Graphene oxide-polystyrene graft polymer (SGO-PS) was prepared by reversible addition-fragmentation chain transfer radical polymerization method. Orthogonal experiments indicated that the optimum synthesis reaction conditions for SGO-PS were as follows: the millimole ratio of chain transfer agent to initiator was 0.15 : 0.3, and the amount of styrene was 8 mL at 80°C for 12 hours. The products were characterized by Fourier transform infrared spectroscopy and thermal weightlessness analysis, and the highest grafting rate of SGO-PS was 62.46%. Then, PLA/SGO-PS nanocomposites were prepared using SGO-PS as fillers by melt intercalation method, and its crystallinity, mechanical properties, and thermal stability were significantly improved. Compared with pure PLA, the crystallinity of PLA/SGO-PS (0.3 wt%) nanocomposites was increased by 5 times. Multiple melting behavior tests showed that the introduction of SGO-PS caused the PLA molecular chain to be discharged into the unit cell in time, and the melting temperature shifted to a higher temperature, which ultimately made the grain structure of PLA composites more complete and stable than pure PLA. The rheological performance test showed that the uniform dispersion of SGO-PS in the PLA matrix inhibited the free movement of the PLA molecular chain and caused higher flow resistance, resulting in an increase in the complex viscosity, storage modulus, and loss modulus of PLA/SGO-PS.

中文翻译：

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基于可逆加成断裂链转移的氧化石墨烯-聚苯乙烯接枝聚合物的合成及其对聚乳酸性质、结晶和流变行为的影响

采用可逆加成-断裂链转移自由基聚合法制备氧化石墨烯-聚苯乙烯接枝聚合物（SGO-PS）。正交实验表明，SGO-PS的最佳合成反应条件为：链转移剂与引发剂的毫摩尔比为0.15:0.3，苯乙烯用量为8mL，80℃反应12小时。通过傅里叶变换红外光谱和热失重分析对产物进行表征，SGO-PS的最高接枝率为62.46%。然后，采用熔融插层法以SGO-PS为填料制备了PLA/SGO-PS纳米复合材料，其结晶度、力学性能和热稳定性均得到显着提高。与纯 PLA 相比，PLA/SGO-PS (0.3 wt%) 纳米复合材料的结晶度提高了 5 倍。多次熔融行为试验表明，SGO-PS的引入使PLA分子链及时释放到晶胞中，熔融温度向更高的温度移动，最终使PLA复合材料的晶粒结构更加完整和稳定比纯PLA。流变性能测试表明，SGO-PS在PLA基体中的均匀分散抑制了PLA分子链的自由运动，导致了更高的流动阻力，导致PLA的复数粘度、储能模量和损耗模量增加/ SGO-PS。最终使 PLA 复合材料的晶粒结构比纯 PLA 更完整和稳定。流变性能测试表明，SGO-PS在PLA基体中的均匀分散抑制了PLA分子链的自由运动，导致了更高的流动阻力，导致PLA的复数粘度、储能模量和损耗模量增加/ SGO-PS。最终使 PLA 复合材料的晶粒结构比纯 PLA 更完整和稳定。流变性能测试表明，SGO-PS在PLA基体中的均匀分散抑制了PLA分子链的自由运动，导致了更高的流动阻力，导致PLA的复数粘度、储能模量和损耗模量增加/ SGO-PS。