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Srisuwan Y, Srihanam P, Rattanasuk S, Baimark Y. Preparation of Poly(L-lactide)- b-poly(ethylene glycol)- b-poly(L-lactide)/Zinc Oxide Nanocomposite Bioplastics for Potential Use as Flexible and Antibacterial Food Packaging. Polymers (Basel) 2024; 16:1660. [PMID: 38932010 PMCID: PMC11207334 DOI: 10.3390/polym16121660] [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: 05/22/2024] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
High-molecular-weight poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) is a flexible and biodegradable bioplastic that has promising potential in flexible food packaging but it has no antibacterial ability. Thus, in this work, the effect of zinc oxide nanoparticles (nano-ZnOs) which have antimicrobial activity on various properties of PLLA-PEG-PLLA was determined. The addition of nano-ZnOs enhanced the crystallization, tensile, UV-barrier, and antibacterial properties of PLLA-PEG-PLLA. However, the crystallization and tensile properties of nanocomposite films decreased again as the nano-ZnO increased beyond 2 wt%. The nano-ZnO was well distributed in the PLLA-PEG-PLLA matrix when the nano-ZnO content did not exceed 2 wt% and exhibited some nano-ZnO agglomerates when the nano-ZnO content was higher than 2 wt%. The thermal stability and moisture uptake of the PLLA-PEG-PLLA matrix decreased and the film's opacity increased as the nano-ZnO content increased. The PLLA-PEG-PLLA/ZnO nanocomposite films showed good antibacterial activity against bacteria such as Escherichia coli and Staphylococcus aureus. It can be concluded that nano-ZnOs can be used as a multi-functional filler of the flexible PLLA-PEG-PLLA. As a result, the addition of nano-ZnOs as a nucleating, reinforcing, UV-screening, and antibacterial agent in the flexible PLLA-PEG-PLLA matrix may provide protection for both the food and the packaging during transportation and storage.
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Affiliation(s)
- Yaowalak Srisuwan
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Kantarawichai 44150, Mahasarakham, Thailand; (Y.S.); (P.S.)
| | - Prasong Srihanam
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Kantarawichai 44150, Mahasarakham, Thailand; (Y.S.); (P.S.)
| | - Surachai Rattanasuk
- Major of Biology, Department of Science and Technology, Faculty of Liberal Arts and Science, Roi-Et Rajabhat University, Selaphum 45120, Roi-Et, Thailand;
| | - Yodthong Baimark
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Kantarawichai 44150, Mahasarakham, Thailand; (Y.S.); (P.S.)
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2
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Tang L, Guo Z, Zhao Q, Fan X, Pu Y, He B, Chen J. A Biodegradable Janus Sponge for Negative Pressure Wound Therapy. Biomacromolecules 2024; 25:2542-2553. [PMID: 38547378 DOI: 10.1021/acs.biomac.4c00046] [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: 04/09/2024]
Abstract
Negative pressure wound therapy (NPWT) is effective in repairing serious skin injury. The dressing used in the NPWT is important for wound healing. In this paper, we develop biodegradable amphiphilic polyurethanes (PUs) and fabricate the PUs into sponges as wound dressings (Bi@e) with Janus pore architectures for NPWT. The Bi@e is adaptive to all the stages of the wound healing process. The Janus Bi@e sponge consists of two layers: the dense hydrophobic upper layer with small pores provides protection and support during negative pressure drainage, and the loose hydrophilic lower layer with large pores absorbs large amounts of wound exudate and maintains a moist environment. Additionally, antibacterial agent silver sulfadiazine (SSD) is loaded into the sponge against Escherichia coli and Staphylococcus aureus with a concentration of 0.50 wt%. The Janus sponge exhibits a super absorbent capacity of 19.53 times its own water weight and remarkable resistance to compression. In a rat skin defect model, the Janus Bi@e sponge not only prevents the conglutination between regenerative skin and dressing but also accelerates wound healing compared to commercially available NPWT dressing. The Janus Bi@e sponge is a promising dressing for the NPWT.
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Affiliation(s)
- Lei Tang
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610065, China
| | - Zhaoyuan Guo
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610065, China
- Ningbo Baoting Biotech Co., Ltd., Ningbo 315010, China
| | - Quan Zhao
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610065, China
| | - Xi Fan
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610065, China
| | - Yuji Pu
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610065, China
| | - Bin He
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610065, China
| | - Jianlin Chen
- School of Laboratory Medicine, Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, Chengdu 610500, China
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3
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Shao GQ, Zhang H, Xu D, Wu FF, Jin YM, Yang N, Yu KJ, Xu XM. Insights into starch-based gels: Selection, fabrication, and application. Int J Biol Macromol 2024; 258:128864. [PMID: 38158059 DOI: 10.1016/j.ijbiomac.2023.128864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/06/2023] [Accepted: 12/15/2023] [Indexed: 01/03/2024]
Abstract
Starch a natural polymer, has made significant advancements in recent decades, offering superior performance and versatility compared to synthetic materials. This review discusses up-to-date diverse applications of starch gels, their fabrication techniques, and their advantages over synthetic materials. Starch gels renewability, biocompatibility, biodegradability, scalability, and affordability make them attractive. Also, advanced theoretical foundations and emerging industrial technologies could further expand their scope and functions inspiring new applications.
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Affiliation(s)
- Guo-Qiang Shao
- School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Huang Zhang
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; Henan University of Animal Husbandry and Economics, 6 Longzihu North Road, Zhengzhou, 450046, PR China
| | - Dan Xu
- School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Feng-Feng Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Ya-Mei Jin
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Na Yang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Ke-Jing Yu
- Key Laboratory of Eco-Textiles, Ministry of Education, School of Textile Science and Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Xue-Ming Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China.
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Baniasadi H, Madani Z, Mohan M, Vaara M, Lipponen S, Vapaavuori J, Seppälä JV. Heat-Induced Actuator Fibers: Starch-Containing Biopolyamide Composites for Functional Textiles. ACS APPLIED MATERIALS & INTERFACES 2023; 15:48584-48600. [PMID: 37787649 PMCID: PMC10591286 DOI: 10.1021/acsami.3c08774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 09/21/2023] [Indexed: 10/04/2023]
Abstract
This study introduces the development of a thermally responsive shape-morphing fabric using low-melting-point polyamide shape memory actuators. To facilitate the blending of biomaterials, we report the synthesis and characterization of a biopolyamide with a relatively low melting point. Additionally, we present a straightforward and solvent-free method for the compatibilization of starch particles with the synthesized biopolyamide, aiming to enhance the sustainability of polyamide and customize the actuation temperature. Subsequently, homogeneous dispersion of up to 70 wt % compatibilized starch particles into the matrix is achieved. The resulting composites exhibit excellent mechanical properties comparable to those reported for soft and tough materials, making them well suited for textile integration. Furthermore, cyclic thermomechanical tests were conducted to evaluate the shape memory and shape recovery of both plain polyamide and composites. The results confirmed their remarkable shape recovery properties. To demonstrate the potential application of biocomposites in textiles, a heat-responsive fabric was created using thermoresponsive shape memory polymer actuators composed of a biocomposite containing 50 wt % compatibilized starch. This fabric demonstrates the ability to repeatedly undergo significant heat-induced deformations by opening and closing pores, thereby exposing hidden functionalities through heat stimulation. This innovative approach provides a convenient pathway for designing heat-responsive textiles, adding value to state-of-the-art smart textiles.
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Affiliation(s)
- Hossein Baniasadi
- Polymer
Technology, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Zahra Madani
- Department
of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Mithila Mohan
- Department
of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Maija Vaara
- Department
of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Sami Lipponen
- Polymer
Technology, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Jaana Vapaavuori
- Department
of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Jukka V. Seppälä
- Polymer
Technology, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
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Srihanam P, Srisuwan Y, Phromsopha T, Manphae A, Baimark Y. Improvement in Phase Compatibility and Mechanical Properties of Poly(L-lactide)- b-poly(ethylene glycol)- b-poly(L-lactide)/thermoplastic Starch Blends with Citric Acid. Polymers (Basel) 2023; 15:3966. [PMID: 37836015 PMCID: PMC10575249 DOI: 10.3390/polym15193966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/03/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
Flexible poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) block copolymer (PLLA-PEG-PLLA) bioplastic has been blended with low-cost thermoplastic starch (TPS) to prepare fully biodegradable bioplastics. However, the mechanical properties of PLLA-PEG-PLLA matrix decrease after the addition of TPS. In this work, citric acid (CA) was used as a compatibilizer to improve the phase compatibility and mechanical properties of PLLA-PEG-PLLA/TPS blends. TPS was first modified with CA (1.5 %wt, 3 %wt, and 4.5%wt) before melt blending with PLLA-PEG-PLLA. The PLLA-PEG-PLLA/modified TPS ratio was constant at 60/40 by weight. CA modification of TPS suppressed the crystallinity and enhanced the thermal stability of the PLLA-PEG-PLLA matrix, as determined through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The compatibility between the dispersed TPS and PLLA-PEG-PLLA phases was improved through modification of TPS with CA, as revealed by the smaller size of the co-continuous TPS phase from scanning electron microscopy (SEM) analysis. Increasing the hydrophilicity of the blends containing modified TPS confirmed the improvement in phase compatibility of the components. From the tensile test, the ultimate tensile strength, elongation at break, and Young's modulus of the blends increased with the CA content. In conclusion, CA showed a promising behavior in improving the phase compatibility and mechanical properties of PLLA-PEG-PLLA/TPS blends. These PLLA-PEG-PLLA/modified TPS blends have potential to be used as flexible bioplastic products.
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Affiliation(s)
- Prasong Srihanam
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand; (P.S.); (Y.S.); (T.P.)
| | - Yaowalak Srisuwan
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand; (P.S.); (Y.S.); (T.P.)
| | - Theeraphol Phromsopha
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand; (P.S.); (Y.S.); (T.P.)
| | - Apirada Manphae
- Scientific Instrument Academic Service Unit, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand;
| | - Yodthong Baimark
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand; (P.S.); (Y.S.); (T.P.)
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6
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Thongsomboon W, Srihanam P, Baimark Y. Preparation of flexible poly(l-lactide)-b-poly(ethylene glycol)-b-poly(l-lactide)/talcum/thermoplastic starch ternary composites for use as heat-resistant and single-use bioplastics. Int J Biol Macromol 2023; 230:123172. [PMID: 36639081 DOI: 10.1016/j.ijbiomac.2023.123172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/19/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
Poly(l-lactide)-b-poly(ethylene glycol)-b-poly(l-lactide) block copolymer (PLLA-PEG-PLLA) is a highly flexible bioplastic, yet its use in practical applications is limited due to its poor heat resistance and high production cost. In this study, talcum was used as a nucleating agent to improve the heat resistance, and thermoplastic starch (TPS) was used as a low-cost filler to reduce the cost of production. PLLA-PEG-PLLA/talcum/TPS and PLLA/talcum/TPS ternary composites with 4 wt% talcum and various TPS contents were prepared by melt blending before injection molding and were then evaluated. When PEG middle-blocks were present, the PLLA-PEG-PLLA-based composites showed a higher crystallinity, more flexibility, and a higher heat resistance than the PLLA-based composites. Although the addition of TPS decreased the heat resistance of all the composites, the PLLA-PEG-PLLA/talcum/TPS composites still had high Vicat softening temperatures (VST, 113-131 °C) and demonstrated a good dimensional stability to heat by maintaining their original shapes upon heat exposure. The biodegradation test in soil suggested that the synergistic effect of the PEG middle-blocks and TPS significantly increased the biodegradability of the PLLA-PEG-PLLA/talcum/TPS composites. This improved heat resistance, lower cost, and accelerated biodegradation make PLLA-PEG-PLLA/talcum/TPS composites a promising material to be used as heat-resistant and single-use bioplastic products.
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Affiliation(s)
- Wiriya Thongsomboon
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand
| | - Prasong Srihanam
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand
| | - Yodthong Baimark
- Biodegradable Polymers Research Unit, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand.
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7
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Kumar R, Alex Y, Nayak B, Mohanty S. Effect of poly (ethylene glycol) on 3D printed PLA/PEG blend: A study of physical, mechanical characterization and printability assessment. J Mech Behav Biomed Mater 2023; 141:105813. [PMID: 37015146 DOI: 10.1016/j.jmbbm.2023.105813] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/23/2023] [Accepted: 03/26/2023] [Indexed: 04/01/2023]
Abstract
The growing popularity of additive manufacturing in the science, industry is associated with high-quality products for futuristic applications. This study presents an in-depth characterization and analysis of the effect of poly (ethylene glycol) (PEG) having molecular weight 6000 g/mol used with various concentrations (1%,3%,5%) to modify the 3D printed Polylactide (PLA) part. The influence of PEG on the morphology, structure, thermal, wettability and mechanical properties of the 3D-printed PLA/PEG part was investigated. Herein, the mechanical property of injection moulding, 3D printed specimens, and finite element analysis (FEA) simulation results were also compared. The structure and properties of PLA/PEG blends were different from those of virgin PLA. By DSC analysis, it was found that the glass transition temperature (Tg) and cold crystallization temperature decreased in the case of the PLA/PEG blend. From TGA it was observed that PLA/PEG blend was thermally stable. It was shown that with the addition of PEG into PLA the tensile strength and young's modulus decrease, whereas elongation percentage and impact strength increase predominantly. The contact angle results indicate that the addition of PEG lowers the contact angle value of the PLA/PEG blend (from 69.32 ± 1.4° to 45.67 ± 1.2°) and increases surface wettability. With 5% PEG loading, PLA/PEG blend showed optimum structural and mechanical properties together with simple processibility.
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8
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Phase Morphology, Mechanical, and Thermal Properties of Calcium Carbonate-Reinforced Poly(L-lactide)- b-poly(ethylene glycol)- b-poly(L-lactide) Bioplastics. Polymers (Basel) 2023; 15:polym15020301. [PMID: 36679183 PMCID: PMC9862968 DOI: 10.3390/polym15020301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/30/2022] [Accepted: 12/31/2022] [Indexed: 01/11/2023] Open
Abstract
Poly(L-lactide) (PLLA) is a promising candidate as a bioplastic because of its non-toxicity and biodegradability. However, the low flexibility of PLLA limits its use in many applications. Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-b-PEG-b-PLLA) block copolymer is of interest for bioplastic applications due to its superior flexibility compared to PLLA. The aim of this work is to modify PLLA-b-PEG-b-PLLA using a low-cost calcium carbonate (CaCO3) filler to improve material properties compared to PLLA/CaCO3 composites. The addition of CaCO3 enhanced the crystallinity and thermal stability for the PLLA-b-PEG-b-PLLA matrix but not for the PLLA matrix, as determined by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). Phase morphology investigation using scanning electron microscopy (SEM) revealed that the interfacial adhesion between PLLA-b-PEG-b-PLLA and CaCO3 was stronger than between PLLA and CaCO3. Additionally, tensile testing was carried out to determine the mechanical properties of the composites. With the addition of CaCO3, the tensile stress and Young's modulus of the PLLA-b-PEG-b-PLLA matrix were increased, whereas these properties of the PLLA matrix were significantly decreased. Thus, CaCO3 shows great promise as an inexpensive filler that can induce nucleation and reinforcing effects for PLLA-b-PEG-b-PLLA bioplastics.
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Li X, Gao B, Zhang S. Adjusting hydrogen bond by Lever Principle to achieve high performance starch-based biodegradable films with low migration quantity. Carbohydr Polym 2022; 298:120107. [DOI: 10.1016/j.carbpol.2022.120107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/06/2022] [Accepted: 09/09/2022] [Indexed: 11/02/2022]
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Enhancement in Crystallizability of Poly(L-Lactide) Using Stereocomplex-Polylactide Powder as a Nucleating Agent. Polymers (Basel) 2022; 14:polym14194092. [PMID: 36236039 PMCID: PMC9571414 DOI: 10.3390/polym14194092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022] Open
Abstract
High-molecular-weight poly(L-lactide) (HMW-PLLA) is a promising candidate for use as a bioplastic because of its biodegradability and compostability. However, the applications of HMW-PLLA have been limited due to its poor crystallizability. In this work, stereocomplex polylactide (scPLA) powder was prepared by precipitation of a low-molecular-weight poly(L-lactide)/poly(D-lactide) (LMW-PLLA/LMW-PDLA) blend solution and investigated for use as a fully-biodegradable nucleating agent for HMW-PLLA compared to LMW-PLLA powder. The obtained LMW-PLLA and scPLA powders with a nearly spherical shape showed complete homo- and stereocomplex crystallites, respectively. HMW-PLLA/LMW-PLLA powder and HMW-PLLA/scPLA powder blends were prepared by melt blending. The LMW-PLLA powder was homogeneously melted in the HMW-PLLA matrices, whereas the scPLA powder had good phase compatibility and was well-dispersed in the HMW-PLLA matrices, as detected by scanning electron microscopy (SEM). It was shown that the enthalpies of crystallization (ΔHc) upon cooling scans for HMW-PLLA largely increased and the half crystallization time (t1/2) dramatically decreased as the scPLA powder content increased; however, the LMW-PLLA powder did not exhibit the same behavior, as determined by differential scanning calorimetry (DSC). The crystallinity content of the HMW-PLLA/scPLA powder blends significantly increased as the scPLA powder content increased, as determined by DSC and X-ray diffractometry (XRD). In conclusion, the fully biodegradable scPLA powder showed good potential for use as an effective nucleating agent to improve the crystallization properties of the HMW-PLLA bioplastic.
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Improvement in Thermal Stability of Flexible Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) Bioplastic by Blending with Native Cassava Starch. Polymers (Basel) 2022; 14:polym14153186. [PMID: 35956700 PMCID: PMC9370861 DOI: 10.3390/polym14153186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 02/05/2023] Open
Abstract
High-molecular-weight poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) triblock copolymer (PLLA-PEG-PLLA) is a promising candidate for use as a biodegradable bioplastic because of its high flexibility. However, the applications of PLLA-PEG-PLLA have been limited due to its high cost and poor thermal stability compared to PLLA. In this work, native cassava starch was blended to reduce the production cost and to improve the thermal stability of PLLA-PEG-PLLA. The starch interacted with PEG middle blocks to increase the thermal stability of the PLLA-PEG-PLLA matrix and to enhance phase adhesion between the PLLA-PEG-PLLA matrix and dispersed starch particles. Tensile stress and strain at break of PLLA-PEG-PLLA films decreased and the hydrophilicity increased as the starch content increased. However, all the PLLA-PEG-PLLA/starch films remained more flexible than the pure PLLA film, representing a promising candidate in biomedical, packaging and agricultural applications.
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12
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Srisuwan Y, Baimark Y. Synergistic effects of PEG middle-blocks and talcum on crystallizability and thermomechanical properties of flexible PLLA- b-PEG- b-PLLA bioplastic. E-POLYMERS 2022. [DOI: 10.1515/epoly-2022-0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In this study, talcum was melt-blended with a flexible poly(l-lactide)-b-polyethylene glycol-b-poly(l-lactide) triblock copolymer (PLLA-PEG-PLLA) with 1, 2, 4, and 8 wt% talcum, for improvement of the crystallization and thermomechanical properties of PLLA-PEG-PLLA compared with PLLA. The crystallizability of PLLA-PEG-PLLA/talcum composites was better than that of PLLA/talcum composites as determined from differential scanning calorimetry. X-ray diffractometry showed that the PLLA-PEG-PLLA/talcum films had a higher degree of crystallinity than the PLLA/talcum films. PEG middle-blocks and talcum showed a synergistic effect for crystallization of PLLA end-blocks. The PLLA-PEG-PLLA/talcum films showed better thermomechanical properties than those of the PLLA/talcum films as determined from dynamic mechanical analysis. This was confirmed from the results of dimensional stability to heat. In summary, the PLLA-PEG-PLLA/talcum composites have potential for use as flexible bioplastics with good dimensional stability to heat.
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Affiliation(s)
- Yaowalak Srisuwan
- Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Biodegradable Polymers Research Unit, Faculty of Science, Mahasarakham University , Mahasarakham 44150 , Thailand
| | - Yodthong Baimark
- Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Biodegradable Polymers Research Unit, Faculty of Science, Mahasarakham University , Mahasarakham 44150 , Thailand
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