Study On Polyamide Fiber Modified By Hyperbranched Polymer

Because of its excellent comprehensive performance with the high impact toughness、 tensile strength wear resistance、electrical properties、self-lubricity and etc.,polyamide (PA-6) is widely used in clothing、packaging、auto、household appliances and optical fiber communication industry etc. Polyamide easy to form hydrogen bonding with water molecule, so it easy to produce thermal degradation in high temperature. The melt viscosity and make processing molding temperature of polyamide is too high, which caused thermal degradation and mechanical properties to decline, applied range of polyamide is limited.Hyperbranched polymer is a young field in the macromolecular science of rapid development, which is the rise of a new branch of polymers with special properties. It is a kind of highly branched polymer that has three-dimensional ellipsoid structure, high solubility, low viscosity, high flowing variability, a large number of terminal functional groups and excellent performance. According to the unique performance of hyperbranched polymer, hyperbranched polymer is introduced in linear, and both are mixed to form blend system. the blend system can improve the performance of the linear polymer, and make its application fields get breakthrough.In this study, through the "one-step" method of the melt polycondensation reaction, a new aromatic hyperbranched polyamide was prepared by AB2monomer,and hyperbranched polyamide was characterized. hyperbranched polyamide as blending components were mixed into PA-6to study its influence on the properties of the blend system.The specific methods of research are as follows:(1)The hyperbranched polyamide was prepared by the step polycondensation reaction with5-aminoisophthalic acid(C8H7NO4)as the monomer and triphenyl phosphate(C18H15O3P) as the condensing agent. and the influence of the experimental conditions on the product are discussed;(2)The complex hyperbranched polyamide was characterized by infrared spectrum;(3)The intrinsic viscosity of hyperbranched polyamide was analyzed, the influence of the reaction conditions on the intrinsic viscosity of hyperbranched polyamide was discussed;(4)According to the proportion of hyperbranched polyamide in the PA-6, the hyperbranched polyamide is introduced in the PA-6to form blend system, the blend and the blending fibre were prepared by using direct molten blending method;(5)The performance of the blend and the blending fibre was analyzed and texted, and the influence of the hyperbranched polyamide on the blend and the blending fibre was studied.The results of the study show that:With increasing the reaction time and temperature, the intrinsic viscosity of the product was increaseed; the spherulites of the blending system became small and crystallinity was increased after the blending system was formed; The blend systems were non-Newtonian and shear-thinning fluid, apparent viscosity of which was decreased with the increased shear rate,The non-Newtonian index and processing temperature was decreased and the shear rate of the blend increased as hyperbranched polymer content enhanced, The viscous flow activity energy of the blend was increased as hyperbranched polymer content enhanced; Rupture strength of the blend at the proportion of1%was slightly lower, rupture strength was obviously reduced when percentage content of the hyperbranched polymer was increased; the compatibility of the blend system was better, its glass transition temperature was dropped and flexibility was increased; the damping performance of the blend system was more enhance than pure polyamide, and With increasing the content of hyperbranched polyamide, the damping performance was increaseed, the impact strength of the blend was improved and its toughness was increased; the thermal stability of the blend system is very preferably; With increasing the content of hyperbranched polyamide, the dyeing and hygroscopic performance enhanced.