1
|
Payungwong N, Sakdapipanich J, Wu J, Ho CC. The Interplay of Protein Hydrolysis and Ammonia in the Stability of Hevea Rubber Latex during Storage. Polymers (Basel) 2023; 15:4636. [PMID: 38139887 PMCID: PMC10747496 DOI: 10.3390/polym15244636] [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: 10/09/2023] [Revised: 11/03/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Natural rubber (NR) latex derived from Hevea brasiliensis is a complex colloid comprising mainly rubber hydrocarbons (latex particles) and a multitude of minor non-rubber constituents such as non-rubber particles, proteins, lipids, carbohydrates, and soluble organic and inorganic substances. NR latex is susceptible to enzymatic attack after it leaves the trees. It is usually preserved with ammonia and, to a lesser extent, with other preservatives to enhance its colloidal stability during storage. Despite numerous studies in the literature on the influence of rubber proteins on NR latex stability, issues regarding the effect of protein hydrolysis in the presence of ammonia on latex stability during storage are still far from resolved. The present work aims to elucidate the interplay between protein hydrolysis and ammoniation in NR latex stability. Both high- and low-ammonia (with a secondary preservative) NR latexes were used to monitor the changes in their protein compositions during storage. High-ammonia (FNR-A) latex preserved with 0.6% (v/v) ammonia, a low 0.1% ammonia/TMTD/ZnO (FNR-TZ) latex, and a deproteinized NR (PDNR) latex were labeled with fluorescence agents and observed using confocal laser scanning microscopy to determine their protein composition. Protein hydrolysis was confirmed via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results revealed that protein hydrolysis increased with the storage duration. The change in protein composition accompanying hydrolysis also allows the spatial distribution of allergenic proteins to be estimated in the latex. Concurrently, the latex stability increased with the storage duration, as measured by the latex's mechanical stability time (MST) and the zeta potential of the latex particles. As monitored by AFM, the surface roughness of the NR latex film increased markedly during extended storage compared with that of the DPNR latex, which remained smooth. These results underscore the pivotal role of ammonia in bolstering NR latex stability brought on by protein hydrolysis, which greatly impacts latex film's formation behavior. NR latex stability underpins the quality of latex-dipped goods during manufacturing, particularly those for medical gloves.
Collapse
Affiliation(s)
- Narueporn Payungwong
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Nakhon Pathom 73170, Thailand;
| | - Jitladda Sakdapipanich
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Nakhon Pathom 73170, Thailand;
| | - Jinrong Wu
- State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China;
| | - Chee-Cheong Ho
- Faculty of Science, University Tunku Abdul Rahman, Sungai Long Campus, Kajang 43000, Malaysia;
| |
Collapse
|
2
|
Dixit M, Taniguchi T. Role of Terminal Groups of cis-1,4-Polyisoprene Chains in the Formation of Physical Junction Points in Natural Rubber. Biomacromolecules 2023; 24:3589-3602. [PMID: 37527033 DOI: 10.1021/acs.biomac.3c00355] [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: 08/03/2023]
Abstract
The terminal structures of cis-1,4-polyisoprene (PI) chains play a vital role in the excellent comprehensive performance of Hevea natural rubber (NR) with properties such as high toughness, tear-resistance, and wet skid resistance. The cis-1,4-polyisoprene chain constituting NR exhibits a distinct composition of terminal groups comprising two distinct types, namely, the ω and α terminal groups. The structures of the ω terminal [dimethyl allyl (DMA)-(trans-1,4-isoprene)2] and six kinds of α end groups of the polymer chain of NR have been explored by utilizing a newly developed 2D NMR method. In the present work, we examine different kinds of PI melt systems, and we choose various combinations of terminal groups: Hydrogen, one DMA unit with two trans isoprene units as ω end groups and ester-terminated isopentene (α1), hydroxy-terminated isopentene (α2), ester-terminated isobutane (α3), hydroxy-terminated isobutane (α4), ester-terminated 1,4-cis-isoprene (α5), and hydroxy-terminated 1,4-cis-isoprene (α6), i.e., HPIH (PI0)-pure PI (Hydrogen terminal), ωPIα1 (PII), ωPIα2 (PIII), ωPIα3 (PIIII), ωPIα4 (PIIV), ωPIα5 (PIV), and ωPIα6 (PIVI). We evaluated dynamic and static properties of PI chains such as the end-to-end vector autocorrelation function (C(t)), its average relaxation time (τ), end-to-end distance (Ree), and radius of gyration (Rg). We also estimated the diffusion coefficients of polyisoprene chains and pair correlation functions [radial distribution functions (RDFs)], potentials of mean force (PMFs) in between end residues, and survival probability (P(τ)) of end groups around the end group by analyzing the equilibrated trajectories of full-atom MD simulations. As per the examination of C(t), rotational relaxation time τ, and RDFs, we discovered that the existence of a strong hydrogen bond in α2-α2, α4-α4, and α6-α6 residues makes the dynamics of hydroxy-terminated polyisoprene chains in ωPIα2,α4,α6 melt systems slower. From the analyses of RDFs and PMFs (W(r)), the association between [α2]-[α2], [α4]-[α4], and [α6]-[α6] terminals in ωPIα2,α4,α6 melt systems is significantly stronger than in [ISO]-[ISO] [Hydrogen terminated 1,4-cis-isoprene:(ISO)] in HPIH and ω-ω, [α1]-[α1], [α3]-[α3], and [α5]-[α5] in ωPIα1,α3,α5 systems. We quantified the fraction of cluster formation of terminal groups of a given size in the seven PI melt systems by employing the criteria of PMFs. It is revealed that no stable cluster exists in the HPIH, ωPIα1, ωPIα3, and ωPIα5 melt systems. Conversely, in the ωPIα2, ωPIα4, and ωPIα6 systems, we perceived stable clusters of [(α2)p] [(α4)p] and [(α6)p] end groups where p (2 ≤ x ≤ 6). These stable clusters validate the presence of physical junction points in between hydroxy-terminated polyisoprene chains through their α2, α4, and α6 terminals. These physical junction points might be crucial for superior properties of NR such as high toughness, crack growth resistance, and strain-induced crystallization.
Collapse
Affiliation(s)
- Mayank Dixit
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Takashi Taniguchi
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| |
Collapse
|
3
|
Tsunoda K, Kitamura Y, Urayama K. Transition of rupture mode of strain crystallizing elastomers in tensile edge-crack tests. SOFT MATTER 2023; 19:1966-1976. [PMID: 36810918 DOI: 10.1039/d3sm00060e] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We revisit the classical results that the fracture energy density (Wb) of strain crystallizing (SC) elastomers exhibits an abrupt change at a characteristic value () of initial notch length (c0) in tensile edge-crack tests. We elucidate that the abrupt change of Wb reflects the transition in rupture mode between the catastrophic crack growth without a significant SIC effect at c0 > and the crack growth like that under cyclic loading (dc/dn mode) at c0 < as a result of a pronounced SIC effect near the crack tip. At c0 < , the tearing energy (G) was considerably enhanced by hardening via SIC near the crack tip, preventing and postponing catastrophic crack growth. The fracture dominated by the dc/dn mode at c0 < was validated by the c0-dependent G characterized by G = (c0/B)1/2/2 and the specific striations on the fracture surface. As the theory expects, coefficient B quantitatively agreed with the result of a separate cyclic loading test using the same specimen. We propose the methodology to quantify the tearing energy enhanced via SIC (GSIC) and to evaluate the dependence of GSIC on ambient temperature (T) and strain rate (). The disappearance of the transition feature in the Wb-c0 relationships enables us to estimate definitely the upper limits of the SIC effects for T (T*) and (*). Comparisons of the GSIC, T*, and * values between natural rubber (NR) and its synthetic analog reveal the superior reinforcement effect via SIC in NR.
Collapse
Affiliation(s)
- Katsuhiko Tsunoda
- Sustainable and Advanced Materials Division, Bridgestone Corporation, Tokyo 187-8531, Japan.
| | - Yuji Kitamura
- Sustainable and Advanced Materials Division, Bridgestone Corporation, Tokyo 187-8531, Japan
| | - Kenji Urayama
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
| |
Collapse
|
4
|
Kashihara K, Oouchi M, Kodama Y, Arai T, Horie M, Kitaura T, Ishii Y. High-Field Nuclear Magnetic Resonance Studies Reveal New Structural Landscape of Sulfur-Vulcanized Natural Rubber. Biomacromolecules 2022; 23:4481-4492. [DOI: 10.1021/acs.biomac.2c00141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kousuke Kashihara
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan
- NMR Science and Development Division, SPring-8 Center, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Muneki Oouchi
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan
- NMR Science and Development Division, SPring-8 Center, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Yu Kodama
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan
| | - Tatsuhiro Arai
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan
| | - Miki Horie
- Chemical Analysis Center, Research & Development HQ, Sumitomo Rubber Industries, Ltd., 1-1-2 Tsutsui, Chuo, Kobe 651-0071, Japan
- WORLD INTEC CO., Ltd., 11-2 Otemachi, Kokurakita-ku, Kitakyushu, Fukuoka 803-0814, Japan
| | - Takehiro Kitaura
- Chemical Analysis Center, Research & Development HQ, Sumitomo Rubber Industries, Ltd., 1-1-2 Tsutsui, Chuo, Kobe 651-0071, Japan
| | - Yoshitaka Ishii
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan
- NMR Science and Development Division, SPring-8 Center, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
- RIKEN Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| |
Collapse
|
5
|
Dixit M, Taniguchi T. Substantial Effect of Terminal Groups in cis-Polyisoprene: A Multiscale Molecular Dynamics Simulation Study. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mayank Dixit
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Takashi Taniguchi
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| |
Collapse
|
6
|
Huang YT, Zhou Y, Yu WW, Liao S, Luo MC. Nonprestretching double-network enabled by physical interaction-induced aggregation. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
Kutsukawa R, Imaizumi R, Suenaga‐Hiromori M, Takeshita K, Sakai N, Misawa S, Yamamoto M, Yamaguchi H, Miyagi‐Inoue Y, Waki T, Kataoka K, Nakayama T, Yamashita S, Takahashi S. Structure‐based engineering of a short‐chain
cis
‐prenyltransferase to biosynthesize nonnatural all‐
cis
‐polyisoprenoids: molecular mechanisms for primer substrate recognition and ultimate product chain‐length determination. FEBS J 2022; 289:4602-4621. [DOI: 10.1111/febs.16392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/27/2022] [Accepted: 02/07/2022] [Indexed: 01/15/2023]
Affiliation(s)
- Ryo Kutsukawa
- Graduate School of Engineering Tohoku University Sendai Japan
| | - Riki Imaizumi
- Department of Material Chemistry Graduate School of Natural Science and Technology Kanazawa University Japan
| | | | | | | | - Shuto Misawa
- Department of Material Chemistry Graduate School of Natural Science and Technology Kanazawa University Japan
| | | | | | | | - Toshiyuki Waki
- Graduate School of Engineering Tohoku University Sendai Japan
| | - Kunishige Kataoka
- Department of Material Chemistry Graduate School of Natural Science and Technology Kanazawa University Japan
| | - Toru Nakayama
- Graduate School of Engineering Tohoku University Sendai Japan
| | - Satoshi Yamashita
- Department of Material Chemistry Graduate School of Natural Science and Technology Kanazawa University Japan
| | - Seiji Takahashi
- Graduate School of Engineering Tohoku University Sendai Japan
| |
Collapse
|
8
|
Becht A, Schollmayer C, Holzgrabe U. Fingerprint spectra for drug formulations using a DOSY filter: Pros and cons. J Pharm Biomed Anal 2022; 214:114723. [DOI: 10.1016/j.jpba.2022.114723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 11/16/2022]
|
9
|
The role of natural rubber endogenous proteins in promoting the formation of vulcanization networks. E-POLYMERS 2022. [DOI: 10.1515/epoly-2022-0043] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Non-rubber components are critical in the formation of the natural rubber (NR) vulcanization network, which leads to outstanding mechanical properties of NR. This study reports the effect of NR endogenous proteins (C-serum protein/lutoid protein [CSP/LP]) on the formation of vulcanization networks at the molecular level. Results indicate that CSP/LP has a positive effect on vulcanization. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses demonstrate that the decrease in vulcanization time of CSP/LP is ascribed to coordination interaction between Zn2+ and amide bond. The interaction increases the availability of ZnO in the matrix, thereby promoting the formation of the vulcanized network. CSP/LP also participates in the construction of the vulcanization network as a new crosslinking point, thus increasing crosslinking density and improving the mechanical properties of the NR. This study provides new research ideas for studying the relationship among component–structure–property of NR materials and developing high-strength and high-toughness elastomer materials.
Collapse
|
10
|
Wang M, Wang R, Chen X, Kong Y, Huang Y, Lv Y, Li G. Effect of non-rubber components on the crosslinking structure and thermo-oxidative degradation of natural rubber. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.109845] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
11
|
Colloidal and rheological properties of natural rubber latex concentrated with hydroxyethyl cellulose and sodium dodecyl sulphate. J Appl Polym Sci 2021. [DOI: 10.1002/app.52034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
12
|
Gimenez-Dejoz J, Tsunoda K, Fukushima Y, Numata K. Computational study of the interaction between natural rubber α-terminal groups and l-quebrachitol, one of the major components of natural rubber. Polym J 2021. [DOI: 10.1038/s41428-021-00569-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
AbstractNatural rubber is a biomaterial with unique physical and chemical features that are indispensable for many industrial applications. It is widely accepted that the α-terminal groups of its biopolymer molecules play a critical role in its exceptional characteristics. Herein, we used molecular dynamics to model recently structurally defined α-terminal groups and their interaction with l-quebrachitol, which is the second most common compound found in natural rubber particles.
Collapse
|
13
|
Hu B, Zhou Y, Luo MC, Wei YC, Liu GX, Liao S, Zhao Y. Influence of l-quebrachitol on the properties of centrifuged natural rubber. E-POLYMERS 2021. [DOI: 10.1515/epoly-2021-0042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Abstract
Nonrubber components (NRCs) play an important role in the outstanding mechanical property of natural rubber (NR). The main inositol component of NRCs in natural rubber latex (NRL) is l-quebrachitol. In this study, the influence of l-quebrachitol on the properties of centrifuged natural rubber (CNR) was investigated. The NRL was centrifuged twice to remove most of the NRCs. After that, l-quebrachitol was added in the latex with per hundreds of rubber (phr) vary from 0% to 0.8%, and the vulcanized CNR were prepared. It is shown that the properties of vulcanized CNR were greatly changed, with T
90 reduced from 19 to 15 min, the tensile strength increased from 5 to 9 MPa, T
g reduced by about 2°C, and the ability for strain-induced crystallization was enhanced. It was proved by FTIR results that l-quebrachitol was linked to the CNR crosslinking network with ester bond.
Collapse
Affiliation(s)
- Benxiang Hu
- Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University , Haikou , 570228 , China
| | - Yuanbing Zhou
- Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University , Haikou , 570228 , China
| | - Ming-Chao Luo
- Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University , Haikou , 570228 , China
| | - Yan-Chan Wei
- Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University , Haikou , 570228 , China
| | - Gui-Xiang Liu
- Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University , Haikou , 570228 , China
| | - Shuangquan Liao
- Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University , Haikou , 570228 , China
| | - Yanfang Zhao
- Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University , Haikou , 570228 , China
| |
Collapse
|
14
|
Aiello F, Gerretzen J, Simons MG, Davies AN, Dani P. A multivariate approach to investigate the NMR CPMG pulse sequence for analysing low MW species in polymers. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2021; 59:172-186. [PMID: 32929750 DOI: 10.1002/mrc.5100] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
Detection and quantification of low molecular weight components in polymeric samples via nuclear magnetic resonance (NMR) spectroscopy can be difficult due to overlapping signal caused by line broadening characteristics of polymers. A way of overcoming this problem could be the exploitation of the difference in relaxation between small molecules and macromolecular species, such as the application of a T2 filter by using the Carr-Purcell-Meiboom-Gill (CPMG) spin-echo pulse sequence. This technique, largely exploited in metabolomics studies, is applied here to material sciences. A Design of Experiments approach was used for evaluating the effect of different acquisition parameters (relaxation delay, echo time and number of cycles) and sample-related ones (concentration and polymer molecular weight) on selected responses, with a particular interest in performing a reliable quantitative analysis. Polymeric samples containing small molecules were analysed by NMR with and without the application of the filter, and analysis of variance was used to identify the most influential parameters. Results indicated that increasing the polymer concentration, hence sample viscosity, further attenuates polymer signals in CPMG experiments because the T2 of those signals tends to decrease with increasing viscosity. The signal-to-noise ratio measured for small molecules can undergo a minimum loss when specific parameters are chosen in relation to the polymer molecular weight. Furthermore, the difference in dynamics between aliphatic and aromatic nuclei, as well as between mobile and stiff polymers, translates into different results in terms of polymer signal reduction, suggesting that the relaxation filter can also be used for obtaining information on the polymer structure.
Collapse
Affiliation(s)
- Federica Aiello
- ECG-MAS, Expert Capability Group - Measurement and Analytical Science, Nouryon Chemicals B.V., Deventer, The Netherlands
| | - Jan Gerretzen
- ECG-MAS, Expert Capability Group - Measurement and Analytical Science, Nouryon Chemicals B.V., Deventer, The Netherlands
| | - Marcel G Simons
- ECG-MAS, Expert Capability Group - Measurement and Analytical Science, Nouryon Chemicals B.V., Deventer, The Netherlands
| | - Antony N Davies
- ECG-MAS, Expert Capability Group - Measurement and Analytical Science, Nouryon Chemicals B.V., Deventer, The Netherlands
- SERC, Sustainable Environment Research Centre, Faculty of Computing Engineering and Science, University of South Wales, Pontypridd, UK
| | - Paulo Dani
- ECG-MAS, Expert Capability Group - Measurement and Analytical Science, Nouryon Chemicals B.V., Deventer, The Netherlands
| |
Collapse
|
15
|
Perea-Buceta J, Rico Del Cerro D, Kilpeläinen I, Heikkinen S. Incorporated diffusion ordered heteronuclear multiple bond correlation spectroscopy, 3D iDOSY-HMBC. Merging of diffusion delay with long polarization transfer delay of HMBC. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 323:106892. [PMID: 33387959 DOI: 10.1016/j.jmr.2020.106892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
3D iDOSY-HMBC pulse sequences allow the simplification of HMBC data of mixtures via separation in the diffusion domain. The presented methods utilize incorporated DOSY approach, iDOSY, where the existing delays of the basic pulse sequence are utilized for diffusion attenuation. In the simplest form of the proposed 3D iDOSY-HMBC sequences, no extra delays or RF-pulses were required, only two diffusion gradients were added within HMBC polarization transfer delay.
Collapse
Affiliation(s)
- Jesus Perea-Buceta
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Daniel Rico Del Cerro
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Ilkka Kilpeläinen
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Sami Heikkinen
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland.
| |
Collapse
|
16
|
Zhang H, Zhang L, Chen X, Wang Y, Zhao F, Luo M, Liao S. The Role of Non-Rubber Components on Molecular Network of Natural Rubber during Accelerated Storage. Polymers (Basel) 2020; 12:polym12122880. [PMID: 33266328 PMCID: PMC7760701 DOI: 10.3390/polym12122880] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/28/2020] [Accepted: 11/29/2020] [Indexed: 11/16/2022] Open
Abstract
Though the non-rubber components have long been recognized to be a vital factor affecting the network of natural rubber (NR), the authentic role of non-rubber components on the network during accelerated storage has not been fully illuminated. This work attempts to clarify the impact of non-rubber components on the network for NR during accelerated storage. A natural network model for NR was proposed based on the gel content, crosslinking density, and the non-rubber components distribution for NR before and after centrifugation. Furthermore, the effect of non-rubber components on the network was investigated during accelerated storage. The results show that terminal crosslinking induced by non-rubber components and entanglements are primary factors affecting the network formation during accelerated storage. By applying the tube model to analyze the stress-strain curves of NR, we found that the contribution of the entanglements to the network formation is larger than that of terminal crosslinking during accelerated storage. The work highlights the role of non-rubber components on the network during accelerated storage, which is essential for understanding the storage hardening mechanism of NR.
Collapse
Affiliation(s)
- Huifeng Zhang
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228, China;
- School of Life and Pharmaceutical Science, Hainan University, Haikou 570228, China
| | - Lu Zhang
- School of Materials Science and Engineering, Hainan University, Haikou 570228, China; (L.Z.); (X.C.); (Y.W.); (F.Z.); (M.L.)
| | - Xu Chen
- School of Materials Science and Engineering, Hainan University, Haikou 570228, China; (L.Z.); (X.C.); (Y.W.); (F.Z.); (M.L.)
| | - Yueqiong Wang
- School of Materials Science and Engineering, Hainan University, Haikou 570228, China; (L.Z.); (X.C.); (Y.W.); (F.Z.); (M.L.)
| | - Fuchun Zhao
- School of Materials Science and Engineering, Hainan University, Haikou 570228, China; (L.Z.); (X.C.); (Y.W.); (F.Z.); (M.L.)
| | - Mingchao Luo
- School of Materials Science and Engineering, Hainan University, Haikou 570228, China; (L.Z.); (X.C.); (Y.W.); (F.Z.); (M.L.)
| | - Shuangquan Liao
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228, China;
- School of Materials Science and Engineering, Hainan University, Haikou 570228, China; (L.Z.); (X.C.); (Y.W.); (F.Z.); (M.L.)
- Correspondence:
| |
Collapse
|
17
|
|
18
|
Yu WW, Xu WZ, Xia JH, Wei YC, Liao S, Luo MC. Toughening natural rubber by the innate sacrificial network. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122419] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
19
|
Exploring the unique characteristics of natural rubber induced by coordination interaction between proteins and Zn2+. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122357] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
20
|
Wei YC, Liu GX, Zhang L, Xu WZ, Liao S, Luo MC. Mimicking the Mechanical Robustness of Natural Rubber Based on a Sacrificial Network Constructed by Phospholipids. ACS APPLIED MATERIALS & INTERFACES 2020; 12:14468-14475. [PMID: 32129596 DOI: 10.1021/acsami.0c01994] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mechanical strength and toughness are usually mutually exclusive, but they can both appear in natural rubber (NR). Previous studies ascribe such excellent properties to highly cis stereoregularity of NR. To our surprise, after the removal of non-rubber components (NRC) by centrifugation, the strength and toughness of NR decrease dramatically. It is still a challenge for us to make out for the problem of how NRC affect the properties of NR. Our group ascribes the superior mechanical robustness of NR to NRC. To further verify such a viewpoint, we add phospholipids (phosphatidylcholines) into NR without NRC. Phosphatidylcholines construct a sacrificial network, which ruptures preferentially upon deformation to dissipate energy. Moreover, some of phosphatidylcholines participate in the vulcanization reaction, which further improves the mechanical strength and energy dissipation. As a result, the mechanical strength and toughness of samples are as high as 21.1 MPa and 49.6 kJ/m2, respectively, which have reached the same level as that of NR. Therefore, this work not only imitates the excellent mechanical robustness of NR but also further provides a rational design for elastomers with excellent mechanical robustness.
Collapse
Affiliation(s)
- Yan-Chan Wei
- Natural Rubber Cooperative Innovation Center of Hainan Province & Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
| | - Gui-Xiang Liu
- Natural Rubber Cooperative Innovation Center of Hainan Province & Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
| | - Ling Zhang
- Natural Rubber Cooperative Innovation Center of Hainan Province & Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
| | - Wen-Zhe Xu
- Natural Rubber Cooperative Innovation Center of Hainan Province & Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
| | - Shuangquan Liao
- Natural Rubber Cooperative Innovation Center of Hainan Province & Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
| | - Ming-Chao Luo
- Natural Rubber Cooperative Innovation Center of Hainan Province & Ministry of Education of PRC, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
| |
Collapse
|
21
|
Sogawa H, Korawit T, Masunaga H, Numata K. Silk/Natural Rubber (NR) and 3,4-Dihydroxyphenylalanine (DOPA)-Modified Silk/NR Composites: Synthesis, Secondary Structure, and Mechanical Properties. Molecules 2020; 25:E235. [PMID: 31935972 PMCID: PMC6982767 DOI: 10.3390/molecules25010235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 12/26/2019] [Accepted: 01/02/2020] [Indexed: 11/16/2022] Open
Abstract
Silk composites with natural rubber (NR) were prepared by mixing degummed silk and NR latex solutions. A significant enhancement of the mechanical properties was confirmed for silk/NR composites compared to a NR-only product, indicating that silk can be applied as an effective reinforcement for rubber materials. Attenuated total reflection Fourier transform infrared (ATR-FTIR) and wide-angle X-ray diffraction (WAXD) analysis revealed that a β-sheet structure was formed in the NR matrix by increasing the silk content above 20 wt%. Then, 3,4-dihydroxyphenylalanine (DOPA)-modified silk was also blended with NR to give a DOPA-silk/NR composite, which showed superior mechanical properties to those of the unmodified silk-based composite. Not only the chemical structure but also the dominant secondary structure of silk in the composite was changed after DOPA modification. It was concluded that both the efficient adhesion property of DOPA residue and the secondary structure change improved the compatibility of silk and NR, resulting in the enhanced mechanical properties of the formed composite. The knowledge obtained herein should contribute to the development of the fabrication of novel silk-based elastic materials.
Collapse
Affiliation(s)
- Hiromitsu Sogawa
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1, Saitama, Wako 351-0198, Japan; (H.S.); (T.K.)
| | - Treratanakulwongs Korawit
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1, Saitama, Wako 351-0198, Japan; (H.S.); (T.K.)
| | - Hiroyasu Masunaga
- Materials Structure Group I, Research & Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan;
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1, Saitama, Wako 351-0198, Japan; (H.S.); (T.K.)
| |
Collapse
|
22
|
Yanchan Wei, Ding A, Jin L, Zhang H, Liao S. Quantitative Analysis of Abnormal Groups on Molecular Chain of Natural Rubber. POLYMER SCIENCE SERIES B 2019. [DOI: 10.1134/s1560090419070030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
23
|
|
24
|
Diehl B, Holzgrabe U, Monakhova Y, Schönberger T. Quo Vadis qNMR? J Pharm Biomed Anal 2019; 177:112847. [PMID: 31505431 DOI: 10.1016/j.jpba.2019.112847] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 01/11/2023]
Abstract
The quantification of a drug, its impurities, and e.g. components of a mixture has become routine in NMR laboratories and many applications have been described in the literature. However, besides simply using 1D 1H or 13C NMR, a number of more advanced methods has been developed and used in the past. Here, we want to describe the applicability of nuclei beyond the classical ones 1H and 13C. Mixtures can be characterized much better by applying various chemometric methods and separating the signals of mixture components can be achieved by DOSY experiments. All these methods contribute to the platform of qNMR methods and extend the possibilities of NMR for quantification and quality evaluation of drugs, excipients, polymers, and plant extracts. However, for quantification purposes, validation is always an issue and it is necessary to think about taking NMR related measures which might be different from the ones considered for chromatographic methods.
Collapse
Affiliation(s)
- Bernd Diehl
- Spectral Service AG, Emil-Hoffmann-Str. 33, 50996, Cologne, Germany
| | - Ulrike Holzgrabe
- Institute of Pharmacy, University of Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany.
| | - Yulia Monakhova
- Spectral Service AG, Emil-Hoffmann-Str. 33, 50996, Cologne, Germany; Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012, Saratov, Russia; Institute of Chemistry, Saint Petersburg State University, 13B Universitetskaya Emb., St Petersburg, 199034, Russia
| | - Torsten Schönberger
- Bundeskriminalamt, Forensic Science Institute, KT43 - Central Analytics II, 65173 Wiesbaden, Germany
| |
Collapse
|