The antagonistic effect of processing and thermal annealing on both the filler structure and the polymer matrix is explored in polymer nanocomposites based on natural rubber with precipitated silica incorporated by coagulation from aqueous suspension followed by roll-milling. Their structure and linear and non-linear rheology have been studied, with a particular emphasis on the effect of high temperature thermal treatment and the number of milling passes. Small-angle X-ray scattering intensities show that the silica is organized in small, unbreakable aggregates containing ca. 50 primary nanoparticles, which are reorganized on a larger scale in filler networks percolating at the highest silica contents. As expected, the filler network structure is found to be sensitive to milling, more milling inducing rupture, as evidenced by the decreasing Payne effect. After thermal treatment, the nanocomposite structure is found to be rejuvenated, erasing the effect of the previous milling on the low-strain modulus. In parallel, the dynamics of the samples described by the rheology or the calorimetric glass-transition temperature remain unchanged, whereas the natural latex polymer network structure is modified by milling towards a more fluid-like rheology, and cannot be recovered.

在基于天然橡胶的聚合物纳米复合材料中研究了加工和热退火对填料结构和聚合物基体的拮抗作用，该聚合物纳米复合材料具有通过从水悬浮液中凝结然后进行辊磨而形成的沉淀二氧化硅。已经研究了它们的结构以及线性和非线性流变学，特别强调了高温热处理的效果和铣削道次。小角X射线散射强度表明，二氧化硅组织成小的，不可破碎的聚集体，其中含有约20％的硅。50种主要纳米粒子，它们在填料网络中以更高的二氧化硅含量进行了大规模重组。不出所料，发现填充物网络结构对铣削敏感，更多的铣削引起破裂，如Payne效应下降所证明。热处理后，发现纳米复合材料结构得以恢复活力，从而消除了先前铣削对低应变模量的影响。同时，由流变学或量热玻璃化转变温度描述的样品的动力学保持不变，而天然胶乳聚合物网络结构通过向更像流体的流变学研磨而被改性，并且不能被恢复。