流延聚丙烯(CPP)薄膜专用树脂结构与性能分析

Structure and properties analysis of cast polypropylene(CPP) film

通过Ⅹ线广角衍射和傅里叶变换红外光谱等表征方法,从常规物性、熔体流动速率、熔融结晶、相对分子质量以及分子量分布影响因素等方面对国产A和B流延聚丙烯(CPP)薄膜专用料与国外牌号C和D薄膜专用料的结构与性能进行对比分析。结果表明:国产A专用料熔融指数较高(0.85 g/min),易于加工;国外牌号专用料的弯曲和冲击性能较好,更有韧性;国产A专用料结晶速度更快,能提高设备的生产能力和生产效率,国外牌号C专用料有相对较高的结晶度,制作成膜料后可提高挺括度;4种专用料的主要晶型都是α晶型,聚丙烯链段中存在嵌段全同立构,是头尾相接的聚丙烯链段结构;4种专用料的分子量分布都在3.8以上,其中国外牌号D专用料的重均相对分子质量(M_(w))较高,分子量分布相对较宽,聚合物热性能和流动性能较好。4种CPP薄膜专用料的基础物性和微观结构较为相近,国产专用料还需在力学性能方面有所提升。

The structure and properties of domestic special materials A and B cast polypropylene filmes and two foreign typical brands C and D were compared and analyzed from the characterization methods such as conventional physical properties,melt flow rate,melting crystallization,relative molecular weight,molecular weight distribution,X-ray wide-angle diffraction and Fourier transform infrared spectroscopy.Results showed that the domestic special material A had a higher melting index of 0.85 g/min,which was easy to process. The bending and impact properties of foreign brand were better,and the material was more ductile. Domestic special material A had faster crystallization property,which could improve the production capacity and production efficiency of equipment,foreign brand C had relatively high crystallinity,which could improve the stiffness after making the film-forming material.The main crystal form of the four special materials were all α crystal,and there was a block isostatic structure in the polypropylene chain segment,which was head and tail connected polypropylene chain segment structure. The molecular weight distribution of the four special materials was above 3.8,of which the weight average molecular weight(M_(w)) of the foreign brand D was relatively high,and the molecular weight distribution was relatively wide. Physical and thermal properties and flow properties were better. The four kinds of polypropylene cast film special materials had similar basic properties and microstructures,and domestic materials needed to be improved in terms of mechanical properties.