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Impact modification of polypropylene as a function of rubber toughening parameters.

机译：聚丙烯的冲击改性与橡胶增韧参数的关系。

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Perhaps the largest class of polymer blends in use today consists of isotactic polypropylene and ethylene-propylene copolymers. Useful materials are obtained from blends over nearly the entire composition range. A particularly useful morphology is a continuous polypropylene matrix with dispersed ethylene-propylene particles having diameters of 0.3 to 5.0 mum. The ethylene-propylene concentration, modulus, particle size and interfacial adhesion are the major factors in determining the toughness of these blends. Using conventional blending techniques, such as extrusion, it is difficult to change one factor without changing the other. In this work we use compositional quenching and post ripening in a quiescent melt to decouple the interrelation of these rubber toughening parameters to gain insights into the mechanisms of rubber toughened polypropylene.; The compositional quenching process requires the preparation of homogeneous polymer solutions followed by a deep adiabatic flash devolatilization. An apparatus capable of producing 2--5 kg of polymer blends was designed and constructed.; The effect of rubber concentration on the toughness of the polymer blend has been studied, focused on the 23% ethylene-propylene copolymer blend. The effect of enhanced interfacial adhesion between the rubber particle and the polypropylene matrix was investigated by the addition of a graft copolymer. The effects of the rubber phase modulus were investigated with the substituting of the ethylene-propylene copolymer with polystyrene and diene 55.; The polymer blends were compression molded with varying melt times to produce a range of particle size via Ostwald ripening. The toughness was investigated as a function of rubber particle size, modulus, and interfacial adhesion over a broad temperature range. A new analysis technique was applied to aid in the determination of the mechanisms of energy dissipation during a notch Izod impact test. The findings of this technique were applied to the current theories of rubber toughening to bring new insight to the mechanisms of energy dissipation.
机译：也许当今使用的最大种类的聚合物共混物包括全同立构聚丙烯和乙烯-丙烯共聚物。有用的材料是从几乎整个组成范围内的混合物中获得的。特别有用的形态是具有直径为0.3至5.0μm的分散的乙烯-丙烯颗粒的连续聚丙烯基质。乙烯-丙烯浓度，模量，粒度和界面粘合力是确定这些共混物韧性的主要因素。使用常规的混合技术，例如挤压，很难改变一个因素而不改变另一个。在这项工作中，我们在静态熔体中使用成分淬火和后熟，以解耦这些橡胶增韧参数的相互关系，从而深入了解橡胶增韧聚丙烯的机理。组成淬火过程要求制备均相的聚合物溶液，然后进行深度绝热的闪蒸脱挥发分。设计和制造了一种能够生产2--5kg聚合物共混物的设备。已经研究了橡胶浓度对聚合物共混物韧性的影响，重点是23％的乙烯-丙烯共聚物共混物。通过添加接枝共聚物，研究了橡胶颗粒与聚丙烯基体之间增强的界面粘合力的作用。用聚苯乙烯和二烯55代替乙烯-丙烯共聚物，研究了橡胶相模量的影响。聚合物共混物以不同的熔融时间压缩模塑，以通过奥斯特瓦尔德熟化产生一定范围的粒径。在较宽的温度范围内，研究了韧性与橡胶粒径，模量和界面粘合力的关系。应用了一种新的分析技术来帮助确定缺口艾佐德冲击试验过程中的能量耗散机理。这项技术的发现被应用于当前的橡胶增韧理论，从而为耗能机理带来了新的见识。

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