改性石墨烯/聚氯乙烯复合材料的制备及性能

采用不同含量的硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH570）对石墨烯（GE）进行改性，将改性GE（KH-GE）与聚氯乙烯（PVC）进行熔融混炼制备KH-GE/PVC复合材料。通过FTIR、Raman、XRD、TEM和SEM表征改性前后GE结构变化，并考察了KH-GE/PVC复合材料的力学性能、导电性能及稳定性能。结果表明，GE∶KH570质量比为1∶2时，KH-GE的层间距较大，改善了GE的团聚，使GE在PVC基体中的分散得到了改善。随着KH-GE含量的增加，KH-GE/PVC复合材料的力学性能显著提高，当KH-GE质量分数为1.5wt%时，KH-GE/PVC复合材料的拉伸强度和断裂伸长率分别为23.98 MPa和226.78%，比未添加KH-GE的PVC复合材料分别提高了51.1%和65.73%；相对于纯PVC，当KH-GE质量分数为1.5wt%时，对应的50%热失重（T_50%）及90%热失重（T_90%）分别从289.81℃和486.01℃提高到298.51℃和596.53℃，提高了KH-GE/PVC复合材料的热稳定性，导电性也显著提高。

Preparation and properties of modified graphene/polyvinyl chloride composites

The modified graphene/polyvinyl chloride (KH-GE/PVC) composites were prepared by melting mixing of polyvinyl chloride and modified graphene. The GE was modified with different contents of silane coupling agent γ-methacryloxy propyl trimethoxy silane(KH570), the changes of graphene structure before and after modification were characterized by FTIR, Raman, XRD, TEM and SEM. And the mechanical properties, electrical conductivity and stability of KH-GE/PVC composites were also investigated. The results show that the layer spacing of KH-GE composite is larger whenW(GE:KH570) mass ratio (the total amount is 100) is 1:2. With the increase of KH-GE content, the mechanical properties of KH-GE/PVC composites are significantly improved. When the content of KH-GE is 1.5wt%, the tensile strength and elongation at break of the composite are 23.98 MPa and 226.78%, respectively, which are 51.1% and 65.73% higher than the composite without KH-GE. Comparing with pure PVC, the corresponding 50% thermal weight loss(T_50%) and 90% thermal weight loss(T_90%) increase from 289.81℃ to 298.51℃ and 486.01℃ to 596.53℃ when the content of KH-GE is 1.5wt%. It indicates that the thermal stability of the films are improved and the conductivity of the composites are also enhanced.