八聚(γ-氨丙基)倍半硅氧烷对芳纶纤维的抗紫外接枝改性

UV resistance graft modification of poly( p-phenylene terephthalamide)fiber with polyhedral oligomeric silsesquioxane

利用氨基与酰氯反应生成酰胺键的原理,采用硫酸预处理和酰氯化反应,得到带有酰氯基的对位芳纶纤维,通过与氨基POSS反应,使对紫外光有选择性吸收的八聚氨基POSS通过酰胺键与纤维连接,从而提高了纤维的抗紫外性能,其理想改性条件为:硫酸浓度70%,处理温度80℃,处理时间10 h。通过对接枝改性后和紫外光照射后纤维的结构表征和性能测试,发现该接枝改性工艺不仅较好保持了纤维的基本结构和热稳定性,而且证实了能够使对位芳纶纤维获得了永久的抗紫外性。

Using the reaction of amino and acyl chloride generated amide bond, poly（ p-phenylene tereph-thalamide） （PPTA） fiber was pretreated with sulfuric acid solution and was acyl chlorinated withdichloromethane and thionyl chloride. Then octa-ammonium polyhedral oligomerie silsesquioxanes （POSS-NH2）linked on the fiber surface with the amide bond, which was as UV absorbent to retard UV photoaging. Under theexisting experimental conditions, a higher sulfuric acid solution concentration, a higber temperature or a longertime was beneficial for increasing the fixed amount of POSS and prevent the UV accelerated ageing of the fiber.The surface morphology, tensile strength, crystallinity, degree of orientation of fibers, and intrinsic viscosity ofpolymer solution were characterized in detail. This graft process with POSS-NH2 introduced silicon elements ontothe fiber surface. Changes in the surface morphology and chemical composition are not obvious, except that partof the amide bonds were broken. After UV-accelerated aging, the degree of orientation and the erystallinity of thefiber and the intrinsic viscosity of polymer solution were well maintained. The condensed and macromolecularstructures of the fiber were well protected.