Bärwinkel Stefanie, Seidel Andreas, Hobeika Sven, Hufen Ralf, Mörl Michaela, Altstädt Volker
Graduate School, University of Bayreuth, Universitätstraße 30, Bayreuth 95447, Germany.
Covestro Deutschland AG, Business Unit Polycarbonates, Research & Development, Development Blends, Leverkusen 51365, Germany.
Materials (Basel). 2016 Aug 5;9(8):659. doi: 10.3390/ma9080659.
Morphology formation during compounding, as well as injection molding of blends containing 60 wt % polycarbonate (PC) and 40 wt % polybutadiene rubber-modified styrene-acrylonitrile copolymers (ABS), has been investigated by transmission electron microscopy (TEM). Profiles of the blend morphology have been recorded in injection-molded specimens and significant morphology gradients observed between their skin and core. A <10 µm thick surface layer with strongly dispersed and elongated nano-scale (streak-like) styrene acrylonitrile (SAN) phases and well-dispersed, isolated SAN-grafted polybutadiene rubber particles is followed by a 50-150 µm thick skin layer in which polymer morphology is characterized by lamellar SAN/ABS phases. Thickness of these lamellae increases with the distance from the specimen's surface. In the core of the specimens the SAN-grafted polybutadiene rubber particles are exclusively present within the SAN phases, which exhibit a much coarser and less oriented, dispersed morphology compared to the skin. The effects of the viscosity of the SAN in the PC/ABS blends on phase morphologies and correlations with fracture mechanics in tensile and impact tests were investigated, including scanning electron microscopy (SEM) assessment of the fracture surfaces. A model explaining the mechanisms of morphology formation during injection molding of PC/ABS blends is discussed.
通过透射电子显微镜（TEM）研究了在含有60 wt%聚碳酸酯（PC）和40 wt%聚丁二烯橡胶改性苯乙烯-丙烯腈共聚物（ABS）的共混物的混合过程以及注塑成型过程中的形态形成。已记录注塑成型试样中共混物形态的轮廓，并观察到其皮层和芯层之间存在明显的形态梯度。一个厚度小于10 µm的表面层，其中苯乙烯丙烯腈（SAN）相强烈分散且呈细长的纳米级（条纹状），还有分散良好的孤立的SAN接枝聚丁二烯橡胶颗粒，接着是一个厚度为50 - 150 µm的皮层，其中聚合物形态以层状SAN/ABS相为特征。这些薄片的厚度随着与试样表面距离的增加而增大。在试样的芯层中，SAN接枝聚丁二烯橡胶颗粒仅存在于SAN相中，与皮层相比，其呈现出更粗大、取向性更差且更分散的形态。研究了PC/ABS共混物中SAN的粘度对相形态的影响以及在拉伸和冲击试验中与断裂力学的相关性，包括对断裂表面的扫描电子显微镜（SEM）评估。讨论了一个解释PC/ABS共混物注塑成型过程中形态形成机制的模型。
