聚丙烯长丝光氧老化过程中断裂强力和特性粘度的相关性

在聚丙烯土工织物光氧老化过程中,由链断裂反应所致的聚合物相对分子质量的降低是导致织物强力下降的主要原因.因为聚合物的相对分子质量可以用其溶液的特性粘度来表征,因此针对光氧老化过程中聚丙烯长丝的特性粘度变化进行了研究,以找到聚丙烯长丝断裂强力下降与相对分子质量之间的关系.在试验中分别采取了人工加速紫外辐射老化和户外自然曝晒老化两种试验条件,并对试验过程中所取的样品同时进行断裂强力测试和特性粘度测试.对测试结果分析后发现：在特性粘度和断裂强力之间存在线性相关.但是不同的老化条件下,线性相关的斜率有所不同,即特性粘度对断裂强力的影响程度有所差别.研究中采用红外光谱方法对各个取样进行了测试,红外测试结果很好地解释了造成上述差别的原因.

Correlation between Tensile Strength and Intrinsic Viscosity of Polypropylene Filaments during Photo-oxidation Process

Sample of polypropylene filaments were exposed to different UV irradiation conditions via artificial accelerated ageing and outdoor atmospheric ageing. The tensile strength of aged samples and also the intrinsic viscosity of the corresponding specimens were tested. FTIR technique was used to determine the carbonylated products that related to molecular weight distribution resulting from UV irradiation. Our results showed that a linear correlation could be established between tensile strength and intrinsic viscosity of samples tested. However, the correlation varies under different ageing conditions. FTIR results indicated that different UV intensity which result in the different carbonylated products during accelerated ageing and outdoor exposure lead to the difference between two correlation above mentioned.