1
|
Tian JJ, Liu X, Ye L, Zhang Z, Quinn EC, Shi C, Broadbelt LJ, Marks TJ, Chen EYX. Redesigned Nylon 6 Variants with Enhanced Recyclability, Ductility, and Transparency. Angew Chem Int Ed Engl 2024; 63:e202320214. [PMID: 38418405 DOI: 10.1002/anie.202320214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/17/2024] [Accepted: 02/28/2024] [Indexed: 03/01/2024]
Abstract
Geminal (gem-) disubstitution in heterocyclic monomers is an effective strategy to enhance polymer chemical recyclability by lowering their ceiling temperatures. However, the effects of specific substitution patterns on the monomer's reactivity and the resulting polymer's properties are largely unexplored. Here we show that, by systematically installing gem-dimethyl groups onto ϵ-caprolactam (monomer of nylon 6) from the α to ϵ positions, both the redesigned lactam monomer's reactivity and the resulting gem-nylon 6's properties are highly sensitive to the substitution position, with the monomers ranging from non-polymerizable to polymerizable and the gem-nylon properties ranging from inferior to far superior to the parent nylon 6. Remarkably, the nylon 6 with the gem-dimethyls substituted at the γ position is amorphous and optically transparent, with a higher Tg (by 30 °C), yield stress (by 1.5 MPa), ductility (by 3×), and lower depolymerization temperature (by 60 °C) than conventional nylon 6.
Collapse
Affiliation(s)
- Jun-Jie Tian
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
| | - Xiaoyang Liu
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA
| | - Liwei Ye
- Department of Chemistry and the Trienens Institute for Sustainability and Energy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA
| | - Zhen Zhang
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
| | - Ethan C Quinn
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
| | - Changxia Shi
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
| | - Linda J Broadbelt
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA
| | - Tobin J Marks
- Department of Chemistry and the Trienens Institute for Sustainability and Energy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA
| | - Eugene Y-X Chen
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
| |
Collapse
|
2
|
Zhu K, Li Y, Huan D, Liu H, Li Z, Jin Y, Zhu C. Effect of Novel Compound Redox Initiators on Polymerization Mechanism and Mechanical Properties of Acrylic Resin. Macromol Rapid Commun 2024; 45:e2300579. [PMID: 37984501 DOI: 10.1002/marc.202300579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/14/2023] [Indexed: 11/22/2023]
Abstract
Aiming at the problems of long reaction time and the risk of explosion polymerization of acrylate resin, a small amount of ferrocene (Fc) is added to the existing dibenzoyl peroxide (BPO)/N,N-dimethylaniline (DMA) initiators, and the compound redox initiators (BPO/DMA/ (Fc)) are proposed for acrylate resin polymerization at room temperature. The effect of the content of Fc in the resin on the reaction efficiency and the molding quality of products is researched, and the initiation mechanism of the compound redox initiators is analyzed. It is found that with the addition of Fc, the reaction time of the resin can be shortened by 68% at maximum, the heat release temperature of the resin can be reduced by 40% at maximum, the molecular weight of the reaction products can be increased by 74% at maximum, the tensile and bending properties of the resin castings are increased by 23% and 35% at maximum, respectively, and the bending strength and bending modulus are increased by 57% and 27% at maximum, respectively. The compound redox initiators proposed in this paper can improve the molding efficiency and quality of the product, lay a foundation for the application of acrylic resin in the field of pultrusion molding, perfusion molding, and other in situ molding of thermoplastic composites.
Collapse
Affiliation(s)
- Kang Zhu
- Department of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
| | - Yong Li
- Department of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
- Jiangsu Key Laboratory of Hi-Tech Research of Wind Turbine Design, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
| | - Dajun Huan
- Department of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
| | - Hao Liu
- Department of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
| | - Ziyi Li
- Department of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
| | - Yue Jin
- Department of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
| | - Chunling Zhu
- Jiangsu Key Laboratory of Hi-Tech Research of Wind Turbine Design, Nanjing University of Aeronautics and Astronautics, Nanjing, 210001, P. R. China
| |
Collapse
|
3
|
Lagarinhos J, Magalhães da Silva S, Oliveira JM. Non-Isothermal Crystallization Kinetics of Polyamide 6/Graphene Nanoplatelets Nanocomposites Obtained via In Situ Polymerization: Effect of Nanofiller Size. Polymers (Basel) 2023; 15:4109. [PMID: 37896362 PMCID: PMC10610371 DOI: 10.3390/polym15204109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/29/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Thermoplastic resin transfer molding (T-RTM) technology was applied to synthesize graphene nanoplatelets-based nanocomposites via anionic ring-opening polymerization (AROP). Polyamide 6 (PA6) was obtained by AROP and was used as the polymeric matrix of the developed nanocomposites. The non-isothermal crystallization behavior of PA6 and nanocomposites was analyzed by differential scanning calorimetry (DSC). Nanocomposites with 0.5 wt.% of graphene nanoplatelets (GNPs) with two different diameter sizes were prepared. Results have shown that the crystallization temperature shifted to higher values in the presence of GNPs. This behavior is more noticeable for the nanocomposite prepared with smaller GNPs (PA6/GN). The crystallization kinetic behavior of all samples was assessed by Avrami and Liu's models. It was observed that GNPs increased the crystallization rate, thus revealing a nucleating ability, and also validated the reduction of half-time crystallization values. Such tendency was also supported by the lower activation energy values determined by Friedman's method.
Collapse
Affiliation(s)
- Joana Lagarinhos
- EMaRT Group—Emerging: Materials, Research, Technology, University of Aveiro, 3810-193 Aveiro, Portugal; (J.L.); (J.M.O.)
- School of Design, Management and Production Technologies, University of Aveiro, Estrada do Cercal 449, 3720-509 Oliveira de Azeméis, Portugal
- CICECO—Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Sara Magalhães da Silva
- EMaRT Group—Emerging: Materials, Research, Technology, University of Aveiro, 3810-193 Aveiro, Portugal; (J.L.); (J.M.O.)
- School of Design, Management and Production Technologies, University of Aveiro, Estrada do Cercal 449, 3720-509 Oliveira de Azeméis, Portugal
- CICECO—Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - José Martinho Oliveira
- EMaRT Group—Emerging: Materials, Research, Technology, University of Aveiro, 3810-193 Aveiro, Portugal; (J.L.); (J.M.O.)
- School of Design, Management and Production Technologies, University of Aveiro, Estrada do Cercal 449, 3720-509 Oliveira de Azeméis, Portugal
- CICECO—Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| |
Collapse
|
4
|
Yoon M, Lim CS. Comparative experiments on amine vs. acid anhydride curing agents for epoxy resin required for automotive parts. JOURNAL OF POLYMER RESEARCH 2023. [DOI: 10.1007/s10965-022-03396-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
5
|
Varghese M, Grinstaff MW. Beyond nylon 6: polyamides via ring opening polymerization of designer lactam monomers for biomedical applications. Chem Soc Rev 2022; 51:8258-8275. [PMID: 36047318 PMCID: PMC9856205 DOI: 10.1039/d1cs00930c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Ring opening polymerization (ROP) of lactams is a highly efficient and versatile method to synthesize polyamides. Within the last ten years, significant advances in polymerization methodology and monomer diversity are ushering in a new era of polyamide chemistry. We begin with a discussion of polymerization techniques including the most widely used anionic ring opening polymerization (AROP), and less prevalent cationic ROP and enzyme-catalyzed ROP. Next, we describe new monomers being explored for ROP with increased functionality and stereochemistry. We emphasize the relationships between composition, structure, and properties, and how chemists can control composition and structure to dictate a desired property or performance. Finally, we discuss biomedical applications of the synthesized polyamides, specifically as biomaterials and pharmaceuticals, with examples to include as antimicrobial agents, cell adhesion substrates, and drug delivery scaffolds.
Collapse
Affiliation(s)
- Maria Varghese
- Departments of Chemistry and Biomedical Engineering, Boston University, Boston, MA, 02215, USA.
| | - Mark W Grinstaff
- Departments of Chemistry and Biomedical Engineering, Boston University, Boston, MA, 02215, USA.
| |
Collapse
|
6
|
Agarwal A, Shaida B, Rastogi M, Singh NB. Food Packaging Materials with Special Reference to Biopolymers-Properties and Applications. CHEMISTRY AFRICA 2022. [PMCID: PMC9389508 DOI: 10.1007/s42250-022-00446-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Food is an important material for survival. The increasing world population, urbanization, and globalization are responsible for more food. This has increased challenges in food storage and safety. Therefore, it is necessary to preserve food by suitable packaging materials. The packaging materials are useful for giving longer life to the food and improving quality during transportation, storage and distribution. Innovations and developments in food packaging, have become very important in the food industry. Variety of packaging materials such as plastics, paper, metal, and glass are used in food packaging. Most widely used packaging materials are non-biodegradable plastics but these are harmful to environment and human health. Therefore, the food industry is in search of environment friendly replacement of non-biodegradable plastics by biodegradable plastics. However, no systematic literature is available on the subject, so there is a need to summarise the available information in a systematic way. Polymer packaging materials with special reference to biodegradable plastics have been discussed in detail. Different type of biodegradable plastics with their functionality and applications in food packaging have been summarised. Literature available has shown that biodegradable plastics are much better for food packaging as compared to other packaging materials. Increasing fundamental research in the use of biodegradable polymers in food packaging and effort to protect the environment, requires deep understanding and there are lot of challenges for commercialization, which are to be tackled. All these aspects have been discussed in this review article.
Collapse
|
7
|
Thermoplastic Composite Materials Approach for More Circular Components: From Monomer to In Situ Polymerization, a Review. JOURNAL OF COMPOSITES SCIENCE 2022. [DOI: 10.3390/jcs6050132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To move toward eco-sustainable and circular composites, one of the most effective solutions is to create thermoplastic composites. The strong commitment of world organizations in the field of safeguarding the planet has directed the research of these materials toward production processes with a lower environmental impact and a strong propensity to recycle the polymeric part. Under its chemical properties, Nylon 6 is the polymer that best satisfies this specific trade-off. The most common production processes that use a thermosetting matrix are described. Subsequently, the work aimed at investigating the use of thermoplastics in the same processes to obtain comparable performances with the materials that are currently used. Particular attention was given to the in situ anionic polymerization process of Nylon 6, starting from the ε-caprolactam monomer. The dependencies of the process parameters, such as temperature, time, pressure, humidity, and concentration of initiators and activators, were therefore investigated with reference to the vacuum infusion technique, currently optimized only to produce thermosetting matrix composites, but promising for the realization of thermoplastic matrix composite; this is the reason why we chose to focus our attention on the vacuum infusion. Finally, three production processes of the polymeric matrix and glass fiber composites were compared in terms of carbon footprint and cumulative energy demand (CED) through life-cycle assessment (LCA).
Collapse
|
8
|
Optimising Crystallisation during Rapid Prototyping of Fe3O4-PA6 Polymer Nanocomposite Component. JOURNAL OF COMPOSITES SCIENCE 2022. [DOI: 10.3390/jcs6030083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Polymer components capable of self-healing can rapidly be manufactured by injecting the monomer (ε-caprolactam), activator and catalyst mixed with a small amount of magnetic nanoparticles into a steel mould. The anionic polymerisation of the monomer produces a polymer component capturing magnetic nanoparticles in a dispersed state. Any microcracks developed in this nanocomposite component can be healed by exposing it to an external alternating magnetic field. Due to the magnetocaloric effect, the nanoparticles locally melt the polymer in response to the magnetic field and fill the cracks, but the nanoparticles require establishing a network within the matrix of the polymer through effective dispersion for functional and uniform melting. The dispersed nanoparticles, however, affect the degree of crystallinity of the polymer depending on the radius of gyration of the polymer chain and the diameter of the magnetic nanoparticle agglomerates. The variation in the degree of crystallinity and crystallite size induced by nanoparticles can affect the melting temperature as well as its mechanical strength after testing for applications, such as stimuli-based self-healing. In the case of in situ synthesis of the polyamide-6 (PA6) magnetic nanocomposite (PMC), there is an opportunity to alter the degree of crystallinity and crystallite size by optimising the catalyst and activator concentration in the monomer. This optimisation method offers an opportunity to tune the crystallinity and, thus, the properties of PMC, which otherwise can be affected by the addition of nanoparticles. To study the effect of the concentration of the catalyst and activator on thermal properties, the degree of crystallinity and the crystallite size of the component (PMC), the ratio of activator and catalyst is varied during the anionic polymerisation of ε-caprolactam, but the concentration of Fe3O4 nanoparticles is kept constant at 1 wt%. Differential Scanning Calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), XRD (X-ray diffraction) and Thermogravimetric analysis (TGA) were used to find the required concentration of the activator and catalyst for optimum properties. It was observed that the sample with 30% N-acetyl caprolactam (NACL) (with 50% EtMgBr) among all of the samples was most suitable to Rapid Prototype the PMC dog-bone sample with the desired degree of crystallinity and required formability.
Collapse
|
9
|
Mashayekhi R, Ehsani M, Ahmadi S, Khajavi R, Khonakdar HA. Synthesis of star-shaped polyamide-6/SiO2 nanocomposites by in situ anionic polymerization through reactive extrusion. IRANIAN POLYMER JOURNAL 2022. [DOI: 10.1007/s13726-021-00994-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
The flame retardancy of polyamide 6—prepared by in situ polymerisation of ε-caprolactam—For T-RTM applications. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2021.109797] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
11
|
Song L, Wang X, Xie P, Ding Y, Dang K, Yang W. Dissolution window in in situ polymerization preparation of polyamide single‐polymer composites. POLYM ENG SCI 2021. [DOI: 10.1002/pen.25690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Le Song
- College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing China
| | - Xiulei Wang
- College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing China
| | - Pengcheng Xie
- College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing China
- State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing China
| | - Yumei Ding
- College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing China
| | - Kaifang Dang
- College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing China
| | - Weimin Yang
- College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing China
- State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing China
| |
Collapse
|
12
|
Minchenkov K, Vedernikov A, Safonov A, Akhatov I. Thermoplastic Pultrusion: A Review. Polymers (Basel) 2021; 13:polym13020180. [PMID: 33419119 PMCID: PMC7825514 DOI: 10.3390/polym13020180] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 11/16/2022] Open
Abstract
Pultrusion is one of the most efficient methods of producing polymer composite structures with a constant cross-section. Pultruded profiles are widely used in bridge construction, transportation industry, energy sector, and civil and architectural engineering. However, in spite of the many advantages thermoplastic composites have over the thermoset ones, the thermoplastic pultrusion market demonstrates significantly lower production volumes as compared to those of the thermoset one. Examining the thermoplastic pultrusion processes, raw materials, mechanical properties of thermoplastic composites, process simulation techniques, patents, and applications of thermoplastic pultrusion, this overview aims to analyze the existing gap between thermoset and thermoplastic pultrusions in order to promote the development of the latter one. Therefore, observing thermoplastic pultrusion from a new perspective, we intend to identify current shortcomings and issues, and to propose future research and application directions.
Collapse
|
13
|
Moisture Adsorption and Desorption Behavior of Raw Materials for the T-RTM Process. JOURNAL OF COMPOSITES SCIENCE 2021. [DOI: 10.3390/jcs5010012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of fiber reinforced plastics (FRPs) has significant potential to reduce the weight of components. As regards the sustainability of these components, thermoplastic matrices offer more potential for recycling than thermoset ones. A possible manufacturing process for the production of thermoplastic FRPs is thermoplastic resin transfer molding (T-RTM). In this very moisture-sensitive process, ε-caprolactam in addition to an activator and catalyst polymerizes anionically to polyamide 6 (aPA6). The anionic polymerization of aPA6 is slowed down or even completely blocked by the presence of water. This study analyses the sorption behavior of the matrix, fiber, binder and core materials for the production of anionic polyamide 6 composites, which are processed in the thermoplastic RTM process. Water vapor sorption measurements are used to determine the adsorption and desorption behavior of the materials. The maximum moisture loading of the materials provides information about the water adsorption capacity of the material. This knowledge is crucial for correct handling of the materials to achieve a fast process and good properties of the final product.
Collapse
|
14
|
Kobayashi K, Tanaka III K, Kogen H. Highly Oxidized γ-Lactam-Containing Natural Products: Total Synthesis and Biological Evaluation. HETEROCYCLES 2021. [DOI: 10.3987/rev-20-944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
15
|
Li M, Tao Y. Poly(ε-lysine) and its derivatives via ring-opening polymerization of biorenewable cyclic lysine. Polym Chem 2021. [DOI: 10.1039/d0py01387k] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Minireview focused on poly(ε-lysine) and its derivatives via ring-opening polymerization of biorenewable cyclic lysine.
Collapse
Affiliation(s)
- Maosheng Li
- Key Laboratory of Polymer Ecomaterials
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022
- People's Republic of China
| | - Youhua Tao
- Key Laboratory of Polymer Ecomaterials
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022
- People's Republic of China
| |
Collapse
|
16
|
Altmann HJ, Steinmann M, Elser I, Benedikter MJ, Naumann S, Buchmeiser MR. Dual catalysis with an
N
‐heterocyclic
carbene and a Lewis acid: Thermally latent
precatalyst
for the polymerization of
ε‐caprolactam. JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1002/pol.20200502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hagen J. Altmann
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
| | - Mark Steinmann
- German Institutes of Textile and Fiber Research Denkendorf Denkendorf Germany
| | - Iris Elser
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
| | | | - Stefan Naumann
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
| | - Michael R. Buchmeiser
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
- German Institutes of Textile and Fiber Research Denkendorf Denkendorf Germany
| |
Collapse
|
17
|
Zabegaeva ON, Sapozhnikov DA, Vygodskii YS. Molecular Composites Based on Polyimides. POLYMER SCIENCE SERIES C 2020. [DOI: 10.1134/s1811238220020174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
18
|
Post-Polymerization Heat Effect in the Production of Polyamide 6 by Bulk Quasiliving Anionic Ring-Opening Polymerization of ε-Caprolactam with Industrial Components: A Green Processing Technique. Processes (Basel) 2020. [DOI: 10.3390/pr8070856] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Bulk, solventless anionic ring-opening polymerization (AROP) of ε-caprolactam (CPL) with high yields, without side products and with short reaction times, initiated by caprolactamate-carbamoylcaprolactam initiating systems belong to green polymerization processes, leading to poly(ε-caprolactam) (Polyamide 6, PA6, Nylon 6). However, the effect of post-polymerization heat (i.e., slow, technically feasible cooling) on the fundamental characteristics of the resulting polymers such as yield and molecular weight distributions (MWDs) have not been revealed thus far. Significant post-polymerization effect was found by us in terms of both monomer conversions and MWDs by carrying out CPL polymerization with industrial components under conditions mimicking thermoplastic reaction transfer molding (T-RTM). Remarkably, higher monomer conversions and molecular weights (MWs) were obtained for Polyamide 6 samples prepared without quenching than that for the quenched polymers at the same reaction times. Independent of quenching or non-quenching, Mn of the resulting polymers as a function of conversion fell in the theoretical line of quasiliving AROP of CPL. At high monomer conversions, significant increase of the MW and broadening of the MWDs occurred, indicating pronounced chain–chain coupling. These findings have fundamental importance for designing processing conditions for in situ polymerization processes of ε-caprolactam by various techniques such as T-RTM, reaction injection molding (RIM), and other processing methods of Polyamide 6.
Collapse
|
19
|
Zhou S, Fu S, Wang H, Deng Y, Zhou X, Sun W, Zhai Y. Acetal-linked polymeric prodrug micelles based on aliphatic polycarbonates for paclitaxel delivery: preparation, characterization, in vitro release and anti-proliferation effects. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2020; 31:2007-2023. [PMID: 32619161 DOI: 10.1080/09205063.2020.1792046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Acidic tumor microenvironment has been extensively explored to design pH-responsive paclitaxel prodrug micelles for cancer therapy. The object of this study is to investigate the pH-responsive drug release behavior and the anti-proliferation capacity of acetal-linked paclitaxel polymeric prodrug micelles. The prodrug was synthesized and evaluated for paclitaxel content. The prodrug micelles were fabricated and characterized for morphology, size, in vitro pH-responsive paclitaxel release, cellular uptake, and anti-proliferation. Paclitaxel content was 33 wt%. The prodrug micelles exhibited spherical structure with the hydrodynamic diameter of 154 nm. Besides, the in vitro paclitaxel release behavior was verified to be pH-responsive, and 77%, 38%, and 17% of parent free paclitaxel was released from the nano-sized prodrug micelles in 13 h at pH 5.5, 6.5, and 7.4, respectively. The cellular uptake assessment demonstrated the time-dependent internalization of prodrug micelles. Meanwhile, CCK-8 analysis showed that prodrug micelles possessed the potent anti-proliferation effects. Prodrug micelles based on aliphatic polycarbonates present a promising platform for cancer chemotherapy due to the pH-responsive characteristics of acetal bond, potent anti-proliferation effects, and outstanding cytocompatibility of aliphatic polycarbonates.
Collapse
Affiliation(s)
- Shiya Zhou
- School of Pharmacy, Shenyang Pharmaceutical University, Shenhe District, Shenyang, China
| | - Shuwen Fu
- School of Pharmacy, Shenyang Pharmaceutical University, Shenhe District, Shenyang, China
| | - Hanle Wang
- School of Material Science and Engineering, Northeast University, Heping District, Shenyang, China
| | - Yanhao Deng
- School of Medical Devices, Shenyang Pharmaceutical University, Shenhe District, Shenyang, China
| | - Xing Zhou
- Hainan Institute of Materia Medica, Haikou, China
| | - Wei Sun
- School of Medical Devices, Shenyang Pharmaceutical University, Shenhe District, Shenyang, China
| | - Yinglei Zhai
- School of Medical Devices, Shenyang Pharmaceutical University, Shenhe District, Shenyang, China
| |
Collapse
|
20
|
Development and Validation of a Test Mold for Thermoplastic Resin Transfer Molding of Reactive PA-6. Polymers (Basel) 2020; 12:polym12040976. [PMID: 32331333 PMCID: PMC7240526 DOI: 10.3390/polym12040976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/02/2020] [Accepted: 04/07/2020] [Indexed: 11/24/2022] Open
Abstract
Thermoplastic resin transfer molding (T-RTM) is a cutting-edge manufacturing technique for high-volume production of composites with a recyclable thermoplastic matrix. Although a number of reactive thermoplastic matrices as well as industrial manufacturing equipment for T-RTM are commercially available today, the design of a T-RTM mold is still based on the skills and personal experience of the designer. This study summarizes the best knowledge and expertise in mold design and manufacturing and introduces an innovative mold for T-RTM. A concept and basic principles for designing a T-RTM mold are formulated in this study. The mold developed is manufactured and validated.
Collapse
|
21
|
Keirouz A, Radacsi N, Ren Q, Dommann A, Beldi G, Maniura-Weber K, Rossi RM, Fortunato G. Nylon-6/chitosan core/shell antimicrobial nanofibers for the prevention of mesh-associated surgical site infection. J Nanobiotechnology 2020; 18:51. [PMID: 32188479 PMCID: PMC7081698 DOI: 10.1186/s12951-020-00602-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022] Open
Abstract
The state-of-the-art hernia meshes, used in hospitals for hernia repair, are predominantly polymeric textile-based constructs that present high mechanical strength, but lack antimicrobial properties. Consequently, preventing bacterial colonization of implanted prosthetic meshes is of major clinical relevance for patients undergoing hernia repair. In this study, the co-axial electrospinning technique was investigated for the development of a novel mechanically stable structure incorporating dual drug release antimicrobial action. Core/shell structured nanofibers were developed, consisting of Nylon-6 in the core, to provide the appropriate mechanical stability, and Chitosan/Polyethylene oxide in the shell to provide bacteriostatic action. The core/shell structure consisted of a binary antimicrobial system incorporating 5-chloro-8-quinolinol in the chitosan shell, with the sustained release of Poly(hexanide) from the Nylon-6 core of the fibers. Homogeneous nanofibers with a "beads-in-fiber" architecture were observed by TEM, and validated by FTIR and XPS. The composite nanofibrous meshes significantly advance the stress-strain responses in comparison to the counterpart single-polymer electrospun meshes. The antimicrobial effectiveness was evaluated in vitro against two of the most commonly occurring pathogenic bacteria; S. aureus and P. aeruginosa, in surgical site infections. This study illustrates how the tailoring of core/shell nanofibers can be of interest for the development of active antimicrobial surfaces.
Collapse
Affiliation(s)
- Antonios Keirouz
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014, St. Gallen, Switzerland
- School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Robert Stevenson Road, Edinburgh, EH9 3FB, UK
| | - Norbert Radacsi
- School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Robert Stevenson Road, Edinburgh, EH9 3FB, UK
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014, St. Gallen, Switzerland
| | - Alex Dommann
- Center for X-Ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland
| | - Guido Beldi
- Department of Visceral Surgery and Medicine, Visceral Surgery, Inselspital University Hospital Bern and University Bern, Freiburgstrasse 18, CH-3010, Bern, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014, St. Gallen, Switzerland
| | - René M Rossi
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014, St. Gallen, Switzerland
| | - Giuseppino Fortunato
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014, St. Gallen, Switzerland.
| |
Collapse
|
22
|
Compensation of Water Influence on Anionic Polymerization of ε-Caprolactam: 1. Chemistry and Experiments. JOURNAL OF COMPOSITES SCIENCE 2020. [DOI: 10.3390/jcs4010007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The activated anionic ring opening polymerization of ε-caprolactam to polyamide 6 is highly sensitive to external influences such as water. Based on an initial theory, preliminary reaction kinetic tests are carried out with the aim of compensating the influence of the water by increasing the activator and catalyst concentration. Different formulations of activator and catalyst were studied to understand the influence of water on the concentration of activator and catalyst. It was found that the compensation of added water with activator and catalyst restores the original reaction time. The test plates produced are examined with regard to their mechanical characteristics and the polymer properties. The results of the mechanical characterization show no significant impairment after compensation of the added water. The physical properties of the matrix show degradation with repeated compensation. However, the residual ε-caprolactam content remains below the critical value of 1% for three of the four investigated formulations.
Collapse
|
23
|
Schmidt BVKJ. Trends in Polymers 2017/2018: Polymer Synthesis. Polymers (Basel) 2019; 12:E39. [PMID: 31881763 PMCID: PMC7023566 DOI: 10.3390/polym12010039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 12/22/2019] [Indexed: 12/25/2022] Open
Abstract
Polymer synthesis is a substantial area in polymer science and marks the starting point for all sorts of polymer materials that have a plethora of applications in everyday life but also in academic research [...].
Collapse
|
24
|
The Effect of the Parameters of T-RTM on the Properties of Polyamide 6 Prepared by in Situ Polymerization. MATERIALS 2019; 13:ma13010004. [PMID: 31861346 PMCID: PMC6982258 DOI: 10.3390/ma13010004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/10/2019] [Accepted: 12/16/2019] [Indexed: 11/19/2022]
Abstract
With the rapid development of the automotive industry, there is also a significant need to improve the raw materials used. Therefore, the demand is increasing for polymer composites with a focus on mass reduction and recyclability. Thermoplastic polymers are preferred because of their recyclability. As the automotive industry requires mass production, they require a thermoplastic raw material that can impregnate the reinforcement in a short cycle time. The most suitable monomer for this purpose is caprolactam. It can be most efficiently processed with T-RTM (thermoplastic resin transfer molding) technology, during which polyamide 6 is produced from the low-viscosity monomer by anionic ring-opening (in situ) polymerization in a tempered mold with a sufficiently short cycle time. Manufacturing parameters, such as polymerization time and mold temperature, highly influence the morphological and mechanical properties of the product. In this paper, the properties of polyamide 6 produced by T-RTM are analyzed as a function of the production parameters. We determine the crystallinity and the residual monomer content of the samples and their effect on mechanical properties.
Collapse
|
25
|
Chemo-rheological studies and monitoring of high-Tg reactive polyphtalamides towards a fast innovative RTM processing of fiber-reinforced thermoplastic composites. Eur Polym J 2019. [DOI: 10.1016/j.eurpolymj.2019.109227] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
26
|
Ageyeva T, Sibikin I, Kovács JG. A Review of Thermoplastic Resin Transfer Molding: Process Modeling and Simulation. Polymers (Basel) 2019; 11:polym11101555. [PMID: 31554305 PMCID: PMC6835702 DOI: 10.3390/polym11101555] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/17/2019] [Accepted: 09/19/2019] [Indexed: 11/16/2022] Open
Abstract
The production and consumption of polymer composites has grown continuously through recent decades and has topped 10 Mt/year. Until very recently, polymer composites almost exclusively had non-recyclable thermoset matrices. The growing amount of plastic, however, inevitably raises the issue of recycling and reuse. Therefore, recyclability has become of paramount importance in the composites industry. As a result, thermoplastics are coming to the forefront. Despite all their advantages, thermoplastics are difficult to use as the matrix of high-performance composites because their high viscosity complicates the impregnation process. A solution could be reactive thermoplastics, such as PA-6, which is synthesized from the ε-caprolactam (ε-CL) monomer via anionic ring opening polymerization (AROP). One of the fastest techniques to process PA-6 into advanced composites is thermoplastic resin transfer molding (T-RTM). Although nowadays T-RTM is close to commercial application, its optimization and control need further research and development, mainly assisted by modeling. This review summarizes recent progress in the modeling of the different aspects of the AROP of ε-CL. It covers the mathematical modeling of reaction kinetics, pressure-volume-temperature behavior, as well as simulation tools and approaches. Based on the research results so far, this review presents the current trends and could even plot the course for future research.
Collapse
Affiliation(s)
- Tatyana Ageyeva
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary.
| | - Ilya Sibikin
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary.
| | - József Gábor Kovács
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary.
| |
Collapse
|
27
|
Boros R, Rajamani PK, Kovács JG. Thermoplastic Overmolding onto Injection-Molded and In Situ Polymerization-Based Polyamides. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E2140. [PMID: 30380762 PMCID: PMC6266369 DOI: 10.3390/ma11112140] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 10/28/2018] [Accepted: 10/29/2018] [Indexed: 11/16/2022]
Abstract
We investigated products manufactured by in situ polymerization, which were reinforced with overmolded ribs. We developed our own mold and prototype product for the project. We used three different materials as preform: a material with a magnesium catalyst, manufactured by in situ polymerization, a Brüggemann AP-NYLON-based in situ polymerization material and an injection-molded PA6 (Durethan B30S, Lanxess GmbH) material. The ribs were formed from the same PA6 material (Durethan B30S, Lanxess GmbH). We examined the effect of the different technological parameters through the pull-off of the overmolded ribs. We measured the effect of melt temperature, holding pressure and holding time, and mold temperature. Considering the individual preforms, we pointed out that monomer migration and binding strength are related, which we concluded from the temperature-dependent mass loss of the materials, measured by thermogravimetric analysis (TGA). Finally, we designed a mold suitable for manufacturing overmolded parts. We designed and built pressure and temperature sensors into the mold to examine and analyze pressures and temperatures around the welding zone of the materials.
Collapse
Affiliation(s)
- Róbert Boros
- Department of Polymer Engineering, Budapest University of Technology and Economics, 1111 Budapest, Hungary.
| | - Praveen Kannan Rajamani
- Department of Polymer Engineering, Budapest University of Technology and Economics, 1111 Budapest, Hungary.
| | - József Gábor Kovács
- Department of Polymer Engineering, Budapest University of Technology and Economics, 1111 Budapest, Hungary.
| |
Collapse
|