| 天然橡胶/顺丁橡胶共混物相容性的分子模拟研究 |
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| 引用本文： | 袁晓钦,曹献超,马艳彬,于人同,赵艳芳,陈永平,廖建和.天然橡胶/顺丁橡胶共混物相容性的分子模拟研究[J].热带作物学报,2022,43(11):2215-2223. |
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| 作者姓名： | 袁晓钦 曹献超 马艳彬 于人同 赵艳芳 陈永平 廖建和 |
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| 作者单位： | 海南大学材料科学与工程学院，海南海口 570228 |
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| 基金项目： | 广东省重点领域研发计划项目(2020B020217001);海南省重大科技项目(ZDKJ2016020) |
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| 摘 要： | 天然橡胶（NR）具有优异的综合性能而广泛应用于各个领域，但较差的耐热、耐老化性能影响了NR制品的使用寿命。天然橡胶与顺丁橡胶（BR）共混可改善制品的拉伸强度、耐磨性、抗撕裂性能，提高制品的使用寿命和耐低温性能，二者共混常用于轮胎制造。NR与BR共混，二者的相容性对共混物的相结构和性能具有重要影响。本研究利用Material Studio软件构建模型，采用分子动力学（MD）和耗散粒子动力学（DPD）模拟方法在分子尺度和介观尺度上对室温下NR/BR共混的相容性进行探讨。通过MD模拟，确定了NR和BR在模拟过程的最小聚合度均为20；构建10/90、30/70、50/50、70/30、90/10的NR/BR共混物模型，并计算每个NR/BR共混模型的相互作用参数χ，发现在NR/BR共混体系中NR与BR分子间的相互作用参数χNR-BR始终比临界相互作用参数χC小；分析了不同质量比NR/BR共混物分子间的径向分布函数，发现NR与BR分子间的径向分布函数ginter(r)始终高于NR与NR、BR与BR同种分子间的径向分布函数，表明共混物中不同种类分子间（NR与BR）的相互作用比同种类分子间（NR与NR、BR与BR）的相互作用要强；DPD模拟得到不同质量比NR/BR共混物的介观形貌，发现共混物分散相的相畴尺寸会随着分散相含量的增加而增加，但均未出现宏观相分离的情况。上述模拟结果表明，NR和BR在室温下以不同质量比混合时，始终表现出良好的相容性。为验证模拟结论是否准确，制备了NR/BR共混物试样，并采用动态热机械分析仪对样品进行测试，结果证实了NR/BR共混体系的混溶性。模拟结论与实验结果相匹配，证明分子模拟研究和预测共混物相容性是可行的，可为共混实验提供可靠的参考和指导。
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| 关 键 词： | 天然橡胶 顺丁橡胶 分子动力学 耗散粒子动力学 相容性 |
| 收稿时间： | 2022-04-11 |
Molecular Simulation on Miscibility of NR/BR Blends |
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| YUAN Xiaoqin,CAO Xianchao,MA Yanbin,YU Rentong,ZHAO Yanfang,CHEN Yongping,LIAO Jianhe.Molecular Simulation on Miscibility of NR/BR Blends[J].Chinese Journal of Tropical Crops,2022,43(11):2215-2223. |
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| Authors: | YUAN Xiaoqin CAO Xianchao MA Yanbin YU Rentong ZHAO Yanfang CHEN Yongping LIAO Jianhe |
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| Institution: | School of Material Science and Engineering, Hannan University, Haikou, Hainan 570228, China |
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| Abstract: | Natural rubber (NR) is widely used in various fields for its excellent comprehensive properties, however its poor heat resistance and aging resistance have great influence on the service life of NR products. The blending of natural rubber and cis-butadiene rubber (BR) could not only improve the tensile strength, wear resistance and tear resistance of the product, but also improve the service life and cold resistance of the product, and the NR/BR blends are widely used in tire manufacturing. When NR and BR are blended, the miscibility between NR and BR has an important influence on the phase structure and properties of the blends. In this study, Material Studio software was used to build the models required for the simulation, and molecular dynamics (MD) and dissipative particle dynamics (DPD) simulation methods were performed to investigate the miscibility of NR/BR blends from the molecular and mesoscopic scales at room temperature. The MD simulation results showed that the minimum repeating units of NR and BR in the NR/BR blend models were both 20; Models of NR/BR blends with mass ratios of 10/90, 30/70, 50/50, 70/30, 90/10 were constructed by Material Studio, by calculating the interaction parameter χ of each NR/BR blends, it was found that the interaction parameters of NR-BR in NR/BR blends (χNR/BR) were always smaller than the critical interaction parameter χC; The radial distribution function between molecules of NR/BR blends with different mass ratios were analyzed, and it was found that the radial distribution function ginter (r) between NR and BR molecules were always higher than that between NR and NR, BR and BR molecules of the same species, which showed that the interaction between different species (NR-BR) in the blends is stronger than the interaction between the same species (NR-NR, BR-BR). In addition, DPD simulations results calculated from the NR/BR blends with different mass ratios showed that the domain size of the dispersed phase of the blends increased with the increase of the dispersed phase content while macroscopic phase separation had always not been detected. Furthermore, the samples of NR/BR blends were prepared, and the miscibility of each blending system was confirmed with the results of dynamic mechanical analysis (DMA). The simulation results show that when NR and BR are blended with different mass ratios at room temperature, they always show good compatibility, and the experimental results are consistent with the results of molecular simulation.For this reason, molecular simulation will be of significance to study and predict the miscibility of polymer blend, and it will provide much more reliable guidance for experiment. |
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| Keywords: | natural rubber cis-butadiene rubber molecular dynamics dissipative particle dynamics miscibility |
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