工艺参数对iPP间歇式发泡及结晶行为的影响-材料加工工程专业论文.docxVIP

摘要 摘要 万方数据 万方数据 关键词：等规聚丙烯 二氧化碳 温度 压力 结晶 发泡 II Abst Abstract Abstract Polypropylene foams have some excellent properties, which can be widely used in daily necessities,aircraft,automotive,etc. The cell size and density have a significant impact on the performance of the products during the polypropylene foaming process, so we can control the cell size and density to improve the performance of the products by regulating the process parameters. In addition, polypropylene is a typical semi-crystalline polymer, the crystallization behavior during polypropylene foaming process affects cell size and density and changes the performance of the products. Therefore, it has an important theoretical and practical significance on the research of the crystallization behavior,foaming behavior and effect of foaming on the crystallization behavior of polypropylene. This paper mainly studied the isotactic polypropylene crystallization behavior, foaming characteristics and their relationship under different process parameters, determing the desired temperature range in which the cells can be produced. The crystallization behavior and foaming properties of isotactic polypropylene were analyzed by differential scanning calorimetry(DSC), scanning electron microscopy(SEM), wide angle X-ray diffraction(WAXD) and universal type Rubber Plastic density, abrasion index, foaming rate tester, the main contents and conclusions are presented here: Effect of process parameters on the crystallization behavior of isotactic polypropylene Within the certain pressure and temperature range, as the CO2 pressure and temperature increased, the melting point of the samples does not change substantially, the initial melting temperature gradually increases, the crystallinity of isotactic polypropylene also has an improvement, but not significantly. Effect of process parameters on the foaming behavior of isotactic polypropylene In the batch foaming process the infiltration pressure and temperature pl