橡胶颗粒增韧高分子材料的超强韧化与微纳米多级有序层状微观结构

Rubber toughening polystyrene polymer is one of the most successful examples, however it is basing on the expense of the strength. The composite has higher toughness as the rubber content increasing, meanwhile its strength loses dramatically. Can it make the toughness increase notably basing on the constant content of rubber domains? Our previous studies showed that the rubber domains through the pressure-induced-flow (PIF) field could be changed from a spherical particle to flat dish-like rubber domains, the flat disk-like rubber domains was segregated by continuous polystyrene phase, thus formed ordered layer-like rubber domains. The ordered layered structure is the same as natural nacre of ordered layered structure. It can further improve rubber-toughening amorphous materials` toughness and strength simultaneously, such as high impact polystyrene HIPS, acrylonitrile-butadiene-styrene copolymer ABS. The project is proposed on previous studies to use micro copolymerization polymer particles with nano rubber domains (such as styrene-butadiene-styrene block copolymer SBS, polybutadiene grafted styrene acrylonitrile copolymer PB-g-SAN, etc.) as toughening phase to tough polymer materials, through pressure-induced flow field, the micro copolymer particles and its internal nano rubbery domains become flat. The micro/nano multistage ordered layered structure can be constructed in the polymer materials, such as polystyrene (PS) and so on, the novel toughening method for further toughening rubber-toughened polymer is established.

橡胶增韧高分子是高分子增韧中最成功的方法之一，但其以牺牲强度为代价，橡胶含量越高增韧效果越好，而强度损失越多。是否能不通过增加橡胶含量提高韧性呢？我们前期的研究表明，橡胶相在压力诱导流动场中可以从球状颗粒演变成为扁平的碟状颗粒，这种扁平碟状橡胶相被聚苯乙烯（PS）连续相隔离，从而形成有序层状结构的橡胶相。这种有序层状结构（与天然贝壳的有序层状结构相似）可以进一步同时提高橡胶相增韧无定形材料（高抗冲聚苯乙烯HIPS与苯乙烯-丁二烯-丙烯腈共聚物ABS）的韧性和强度。本项目拟在此基础上，用含纳米橡胶相的共聚高分子微米颗粒（如苯乙烯-丁二烯-苯乙烯嵌段共聚物SBS、聚丁二烯接枝苯乙烯丙烯腈共聚物PB-g-SAN等）作为增韧相，在压力诱导流动场中，微米级高分子颗粒及其中的纳米橡胶相变形为扁平状，在聚苯乙烯等高分子材料中构筑微纳米多级有序层状结构，建立橡胶相增韧高分子材料进一步强韧化的新方法。

项目执行期间发表论文18篇，会议论文2篇，申请发明专利3件，授权1件，培养研究生3名，全面完成了项目的各项计划任务，达到预期目标，取得以下主要成果。.1、建立了微纳米多级有序层状特征参数与宏观性能之间关系； .本项目用压力诱导流动成型方法，可以在通用高分子材料中构筑多级有序层状微观结构，与此同时大量引入无机刚性粒子作为银纹的引发点，银纹的增加导致能量耗散的增加，从而大幅度提高材料的冲击韧性，并同时提高强度，而且刚性粒子引入会增加其刚性。以含纳米橡胶相的共聚高分子微米颗粒（如苯乙烯-丁二烯-苯乙烯嵌段共聚物SBS、聚丁二烯接枝苯乙烯丙烯腈共聚物PB-g-SAN等）作为增韧相，在压力诱导流动场中，微米级的高分子球状颗粒及其中的纳米橡胶球状颗粒变形为扁平状，在PS、SAN、PP、PPS与PLA等高分子材料中构筑微纳米多级有序层状结构。研究了微观层状结构参数对力学性能和断裂行为的影响规律。.2、在无定形高分子中建立的强韧一体化模型及对其机理的解析；.揭示了橡胶颗粒增韧无定形高分子体系的演变规律及其增强增韧机理，建立了通过形成取向扁平颗粒，提高银纹引发和终止效率，同时提高韧性、强度和刚性的通用高分子材料高性能化新方法。以典型的橡胶增韧高分子（SAN、PS）为研究对象，系统地研究了PIF成型过程中多级微观结构演变规律。这对无定形通用高分子材料的高性能化具有重要意义，并且对半结晶高分子，尤其是特种工程塑料也进行相关探索并收到了较好的结果。