Citation: Han Liu, Guang-Su Huang, Lai-Yun Wei, Jian Zeng, Xuan Fu, Cheng Huang, Jin-Rong Wu. Inhomogeneous Natural Network Promoting Strain-induced Crystallization: A Mesoscale Model of Natural Rubber[J]. Chinese Journal of Polymer Science, ;2019, 37(11): 1142-1151. doi: 10.1007/s10118-019-2267-3 shu

Inhomogeneous Natural Network Promoting Strain-induced Crystallization: A Mesoscale Model of Natural Rubber

College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China

Corresponding author: Guang-Su Huang, guangsu-huang@hotmail.com Jin-Rong Wu, wujinrong@scu.edu.cn
Received Date: 18 February 2019
Revised Date: 21 March 2019
Available Online: 6 June 2019

Although synthetic rubbers show continuously improved mechanical properties, natural rubber (NR) remains irreplaceable in the rubber family due to its superior mechanical properties. A mainstream viewpoint regarding the superiority of NR is that NR possesses a natural network formed by linking the poly(cis-1,4-isoprene) chain terminals to protein and phospholipid aggregates; after vulcanization, the natural network additionally contributes to rubber mechanics by both increasing the network density and promoting the strain-induced crystallization (SIC) behavior. However, the reason why the natural network promotes SIC is still unclear; in particular, only using the increased network density cannot explain our finding that the NR shows smaller onset strain of SIC than Gel (the gel component of NR with higher network density) and even vulcanized NR. Herein, we point out that the inhomogeneous chain deformation is the alternative reason why SIC of NR takes place at smaller strain than that of Gel. More specifically, although the natural network is homogenous on the subchain length scale based on the proton double-quantum NMR results, it is essentially inhomogeneous on mesoscale (100 nm), as revealed by the small angle X-ray scattering analysis. This inhomogeneous network also leads to the mesoscale deformation inhomogeneity, as detected by the orientation of stearic acid (SA) probe, thus resulting in the smaller onset strain of SIC of NR. Based on the experimental results, a mesoscale model is proposed to qualitatively describe the crucial roles of inhomogeneous structure and deformation of natural network in NR’s mechanical properties, providing a clue from nature to guide the development of high-performance rubbers with controlled structures at mesoscale.
- Natural Rubber,
- Inhomogeneous natural network,
- Strain-induced crystallization,
- Mesoscale model
1. [1]
  Kohjiya, S; Ikeda, Y. Chemistry, Manufacture and applications of natural rubber. Cambridge, UK, Woodhead Publishing, 2014.
2. [2]
  Gent, A.; Kawahara, S.; Zhao, J. Crystallization and strength of natural rubber and synthetic cis-1,4-polyisoprene. Rubber Chem. Technol. 1998, 71, 668–678. doi: 10.5254/1.3538496
3. [3]
  Tanaka, Y. Structural characterization of natural polyisoprenes: Solve the mystery of natural rubber based on structural study. Rubber Chem. Technol. 2001, 74, 355–375. doi: 10.5254/1.3547643
4. [4]
  Tarachiwin, L.; Sakdapipanich, J.; Ute, K.; Kitayama, T.; Bamba, T.; Fukusaki, E.-i.; Kobayashi, A.; Tanaka, Y. Structural Characterization of α-terminal group of natural rubber. 1. Decomposition of branch-points by lipase and phosphatase treatments. Biomacromolecules 2005, 6, 1851–1857.
5. [5]
  Tarachiwin, L.; Sakdapipanich, J.; Ute, K.; Kitayama, T.; Tanaka, Y. Structural characterization of α-terminal group of natural rubber. 2. Decomposition of branch-points by phospholipase and chemical treatments. Biomacromolecules 2005, 6, 1858–1863. doi: 10.1021/bm058004p
6. [6]
  Karino, T.; Ikeda, Y.; Yasuda, Y.; Kohjiya, S.; Shibayama, M. Nonuniformity in natural rubber as revealed by small-angle neutron scattering, small-angle X-ray scattering, and atomic force microscopy. Biomacromolecules 2007, 8, 693-699. doi: 10.1021/bm060983d
7. [7]
  Toki, S.; Burger, C.; Hsiao, B. S.; Amnuaypornsri, S.; Sakdapipanich, J.; Tanaka, Y. Multi-scaled microstructures in natural rubber characterized by synchrotron X-ray Scattering and optical microscopy. J. Polym. Sci., Part B: Polym. Phys. 2008, 46, 2456–2464. doi: 10.1002/polb.v46:22
8. [8]
  Amnuaypornsri, S.; Sakdapipanich, J.; Toki, S.; Hsiao, B.; Ichikawa, N.; Tanaka, Y. Strain-induced crystallization of natural rubber: effect of proteins and phospholipids. Rubber Chem. Technol. 2008, 81, 753–766. doi: 10.5254/1.3548230
9. [9]
  Tanaka, Y.; Tarachiwin, L. Recent advances in structural characterization of natural rubber. Rubber Chem. Technol. 2009, 82, 283–314. doi: 10.5254/1.3548250
10. [10]
  Toki, S.; Hsiao, B. S.; Amnuaypornsri, S.; Sakdapipanich, J. New insights into the relationship between network structure and strain-induced crystallization in un-vulcanized and vulcanized natural rubber by synchrotron X-ray diffraction. Polymer 2009, 50, 2142–2148. doi: 10.1016/j.polymer.2009.03.001
11. [11]
  Che, J.; Burger C.; Toki, S.; Rong, L.; Hsiao, B. Crystal and crystallites structure of natural rubber and synthetic cis-1,4-polyisoprene by a new two dimensional wide angle X-ray diffraction simulation method. I. Strain-induced crystallization. Macromolecules 2013, 46, 4520–4528.
12. [12]
  Toki, S.; Che, J.; Rong, L.; Hsiao, B. S.; Amnuaypornsri, S.; Nimpaiboon, A.; Sakdapipanich, J. Entanglements and networks to strain-induced crystallization and stress-strain relations in natural rubber and synthetic polyisoprene at various temperatures. Macromolecules 2013, 46, 5238–5248. doi: 10.1021/ma400504k
13. [13]
  Liu, J.; Wang, S.; Tang, Z.; Huang, J; Guo, B.; Huang, G. Bioinspired engineering of two different types of sacrificial bonds into chemically cross-linked cis-1,4-polyisoprene toward a high-performance elastomer. Macromolecules 2016, 49, 8593–8604. doi: 10.1021/acs.macromol.6b01576
14. [14]
  Zhou, Y.; Kosugi, K.; Yamamoto, Y.; Kawahara, S. Effect of nonrubber components on the mechanical properties of natural rubber. Polym. Adv. Technol. 2017, 28, 159–165. doi: 10.1002/pat.3870
15. [15]
  Wu, J.; Qu, W.; Huang, G.; Wang, S.; Huang, C.; Liu, H. Super-resolution fluorescence imaging of spatial organization of proteins and lipids in natural rubber. Biomacromolecules 2017, 18, 1705–1712. doi: 10.1021/acs.biomac.6b01827
16. [16]
  Sainumsai, W.; Toki, S.; Amnuaypornsri, S.; Nimpaiboon, A.; Sakdapipanich, J.; Rong, L.; Hsiao, B.; Suchiva, K. Dependence of the onset of strain-induced crystallization of natural rubber and its synthetic analogue on crosslink and entanglement by using synchrotron X-Ray. Rubber Chem. Technol. 2017, 90, 728–742. doi: 10.5254/rct.18.82693
17. [17]
  Gabrielle, B.; Gomez, E.; Korb, J. Probing rubber cross-linking generation of industrial polymer networks at nanometer scale. J. Phys. Chem. B 2016, 120, 5581–5589.
18. [18]
  Valentin, J. L.; Posadas, P.; Fernandez-Torres, A.; Malmierca, M. A.; Gonzalez, L.; Chasse, W.; Saalwaechter, K. Inhomogeneities and chain dynamics in diene rubbers vulcanized with different cure systems. Macromolecules 2010, 43, 4210–4222. doi: 10.1021/ma1003437
19. [19]
  Tosaka, M.; Murakami, S.; Poompradub, S.; Kohjiya, S.; Ikeda, Y.; Toki, S.; Sics, I.; Hsiao, B. S. Orientation and crystallization of natural rubber network as revealed by WAXD using synchrotron radiation. Macromolecules 2004, 37, 3299–3309. doi: 10.1021/ma0355608
20. [20]
  Nie, Y. J.; Gao, H. H.; Yu, M. H.; Hu, Z. M.; Reiter, G.; Hu, W. B. Competition of crystal nucleation to fabricate the oriented semi-crystalline polymers. Polymer 2013, 54(13), 3402–3407. doi: 10.1016/j.polymer.2013.04.047
21. [21]
  Zhang, M. M.; Zha, L. Y.; Gao, H. H.; Nie, Y. J.; Hu, W. B. How polydispersity of network polymers influences strain-induced crystal nucleation in a rubber. Chinese J. Polym. Sci. 2014, 32(9), 1218–1223. doi: 10.1007/s10118-014-1495-9
22. [22]
  Weng, G.; Huang, G.; Qu, L.; Nie, Y.; Wu, J. Large-scale orientation in a vulcanized stretched natural rubber network: Proved by in situ synchrotron X-ray diffraction. J. Phys. Chem. B 2010, 114, 7179–7188.
23. [23]
  Ikeda, Y.; Higashitani, N.; Hijikata, K.; Kokubo, Y.; Morita, Y.; Shibayama, M.; Osaka, N.; Suzuki, T.; Endo, H.; Kohjiya, S. Vulcanization: New focus on a traditional technology by small-angle neutron scattering. Macromolecules 2009, 42, 2741–2748. doi: 10.1021/ma802730z
24. [24]
  Ikeda, Y.; Yasuda, Y.; Hijikata, K.; Tosaka, M.; Kohjiya, S. Comparative study on strain-induced crystallization behavior of peroxide cross-linked and sulfur cross-linked natural rubber. Macromolecules 2008, 41, 5876–5884. doi: 10.1021/ma800144u
25. [25]
  Suzuki, T.; Osaka, N.; Endo, H.; Shibayama, M.; Ikeda, Y.; Asai, H.; Higashitani, N.; Kokubo, Y.; Kohjiya, S. Nonuniformity in cross-linked natural rubber as revealed by contrast-variation small-angle neutron scattering. Macromolecules 2010, 43, 1556–1563. doi: 10.1021/ma9019416
26. [26]
  Toki, S.; Sics, I.; Ran, S. F.; Liu, L. Z.; Hsiao, B. S.; Murakami, S.; Senoo, K.; Kohjiya, S. New insights into structural development in natural rubber during uniaxial deformation by in situ synchrotron X-ray diffraction. Macromolecules 2002, 35, 6578–6584. doi: 10.1021/ma0205921
27. [27]
  Tosaka, M. A Route for the thermodynamic description of strain-induced crystallization in sulfur-cured natural rubber. Macromolecules 2009, 42, 6166–6174. doi: 10.1021/ma900954c
28. [28]
  Candau, N.; Laghmach, R.; Chazeau, L.; Chenal J.; Gauthier, C.; Biben, T.; Munch, E. Strain-induced crystallization of natural rubber and cross-link densities heterogeneities. Macromolecules 2014, 47, 5815–5824. doi: 10.1021/ma5006843
29. [29]
  Ran, S.; Fang, D.; Zong, X.; Hsiao, B. S.; Chu, B.; Cunniff, P. M. Structural changes during deformation of Kevlar fibers via on-line synchrotron SAXS/WAXD techniques. Polymer 2001,42, 1601–1612. doi: 10.1016/S0032-3861(00)00460-2
30. [30]
  Shibayama, M.; Kurokawa, H.; Nomura, S.; Muthukumar, M.; Stein, R.; Roy, S. Small-angle neutron scattering from poly(vinyl alcohol)-borate gels. Polymer 1992, 33, 2883–2890. doi: 10.1016/0032-3861(92)90072-5
31. [31]
  Ott, M.; Perez-Aparicio, R.; Schneider, H.; Sotta, P.; Saalwachter, K. Microscopic Study of chain deformation and orientation in uniaxially strained polymer networks: NMR results versus different network models. Macromolecules 2014, 47, 7597–7611. doi: 10.1021/ma5012655
32. [32]
  Saalwaechter, K. Proton Multiple-quantum NMR for the study of chain dynamics and structural constraints in polymeric soft materials. Progress in nuclear magnetic resonance spectroscopy 2007, 51, 1-35. doi: 10.1016/j.pnmrs.2007.01.001
33. [33]
  Saalwächte, K. Chain order and cross-link density of elastomers as investigated by proton multiple-quantum NMR. Macromolecules 2005, 38, 9650–9660. doi: 10.1021/ma051238g
34. [34]
  Pérez-Aparicio, R.; Schiewek, M.; López Valentín, J.; Schneider, H.; Long, D.; Saphiannikova, M.; Sotta, P.; Saalwächter, K.; Ott, M. Local chain deformation and overstrain in reinforced elastomers: An NMR study. Macromolecules 2013, 46, 5549–5560. doi: 10.1021/ma400921k
35. [35]
  Chasse, W.; Valentin, J.; Genesky, G.; Cohen, C.; Saalwachter, K. Precise dipolar coupling constant distribution analysis in proton multi-quantum NMR Elastomers. J. Chem. Phys. 2011, 134, 044907-044916. doi: 10.1063/1.3534856
36. [36]
  Naumovaa, A.; Tschierskeb, C; Saalwächtera, K. Orientation-dependent proton double-quantum NMR build-up function for soft materials with anisotropic mobility. Solid State Nucl. Mag. 2017, 82, 22–28. doi: 10.1016/j.ssnmr.2017.01.006
37. [37]
  Eriko Sato Matsuo, Michal Orkisz, Shao-Tang Sun, Yong Li, Toyoichi Tanaka. Origin of structural inhomogeneity in polymer gels. Macromolecules 1994, 27, 6791–6796. doi: 10.1021/ma00101a018
38. [38]
  Brostowitz, N.; Weiss, R.; Cavicchi, K. Facile fabrication of a shape memory polymer by swelling cross-linked natural rubber with stearic acid. ACS Macro Lett. 2014, 3, 374–377. doi: 10.1021/mz500131r
39. [39]
  Boue, F.; Bastide, J.; Buzier, M.; Collette, C.; Lapp, A.; Herz, J. Dynamics of permanent and temporary networks: Small angle neutron scattering measurements and related remarks on the classical models of rubber deformation. Prog. Colloid Polym. Sci. 1987, 75, 152–170.
40. [40]
  Wagner, M. H. Analysis of small-angle neutron scattering data on poly(dimethylsiloxane) network unfolding. Macromolecules 1994, 27, 5223–5226. doi: 10.1021/ma00096a056
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