粒子-聚合物相互作用与粒子-粒子相互作用对聚合物基纳米复合物力学性能的影响

聚合物基纳米复合物(PNCs)具有比传统高分子材料更加优异的光学、力学、热力学等性能,广泛应用于各个工程领域.而纳米粒子(NPs)对材料性能提高的机理则是当前聚合物纳米复合物领域研究的重要问题,聚合物纳米复合体系相互作用的影响因素众多,至今尚未明确并完整建立复合体系相互作用与性能增强之间的关系.本文总结了近年来关于纳米粒子填充聚合物基体力学性能的研究,从粒子-聚合物相互作用和粒子-粒子相互作用角度阐述了聚合物纳米复合体系力学性能的增强机理,并根据体系中不同的结构关系分别总结了聚合物/未改性纳米粒子复合体系和聚合物/聚合物接枝纳米粒子复合体系中影响力学性能的因素.该部分内容具有重要的理论和实践意义,有助于构建复合体系微观结构与宏观性能之间的关系,进而对微观层面调控PNCs的力学性能提供指导.

Effects of Particle-polymer Interactions and Particle-particle Interactions on Mechanical Properties of Polymer Nanocomposites

The inclusion of nanoparticles(NPs)or polymer-grafted nanoparticles(PGNPs)can impart the polymeric materials with enhanced properties in polymer nanocomposites(PNCs).Compared to the traditional polymer materials,the excellent performances of PNCs such as superior mechanical,thermodynamic,and optical properties have become a prominent aspect of scientific research.However,it still remains unclear about the relationship between interfacial interactions and mechanical enhancement in PNCs because the various factors i.e.,grafting densityσ(chains/nm2),the chain length of matrix versus the grafted polymer(P/N)and nanoparticle size can complicatedly affect the interfacial characteristics.Understanding the enhancement mechanism of the NPs/PGNPs in PNCs is,therefore,of crucial importance to modulate the properties of PNCs.Based on the successes and failures of the previous study,this review summarizes the mechanism of mechanical enhancement in PNCs,mainly from two perspectives:"particle-polymer interaction"and"particle-particle interaction".According to the different structural and conformation properties in PNCs,these two aspects are discussed in polymer/NPs nanocomposites and polymer/PGNPs nanocomposites,respectively.Strong reinforcement in PNCs inclusion of unmodified NPs is obtained at low NPs contents due to the overlapping of the glassy layer between NPs,and the network structure occurring at high NPs contents can significantly improve the mechanical properties of the polymer/NPs system.The decoration of grafted chains on the NPs surface can remarkably enhance the interfacial interactions between NPs and matrix.Mechanical properties of the grafted system can be affected by the different dispersion states of PGNPs,through controllingσ,P/N and NPs size.The"particle-particle interaction"under different aggregates is the main contribution to the enhancement of the mechanical properties in polymer/PGNPs system.It is anticipated that this review can be helpful to establish the relationship between the microstructure and macroscopic performance in PNCs and to provide guidance on modulating the mechanical properties of PNCs.