两性聚苯硫醚的制备和性能

Synthesis and Properties of a Ampholytic Polyphenylene Sulfide(PPS)

通过对磺化聚苯硫醚(P-SO_3)的溴化、季铵基和叔铵基的取代反应,制备了两性聚苯硫醚(P-SO_3-TMA和P-SO_3-DMA).测试了两性聚苯硫醚的溶解性、比浓黏度、特性粘数和热稳定性等性能,研究了几种关键因素对这些性能的影响。结果表明:通过溴化和取代反应,在磺化聚苯硫醚分子链上引入极性基团(季铵基和叔铵基)增强了分子链极性,使两性聚苯硫醚能溶解在极性较大的溶剂中,使P-SO_3-TMA和P-SO_3-DMA的比浓黏度随着水溶液pH值的增加大致呈上升趋势;水溶液的稀释使分子链上磺酸基与季铵基或叔铵基之间的相互吸引力减弱,构象变得疏松,从而使比浓黏度增大;受阳离子影响的大小排序为:NH<_4^+Li+<Na^+<K^+,Mg^(2+)<Ca^(2+),受阴离子影响的大小排序为Br-<C1^-<I^-;在纯水中,两性聚苯硫醚表现出一种比磺化聚苯硫醚稳定的剪切速率.在饱和食盐水中,两性聚苯硫醚的黏度随着剪切速率的增大迅速降低。耐温性较磺化聚苯硫醚也得到提高。

Ampholytic polyphenylene sulfide （P-SO3-TMA and P-SO3-DMA） was prepared from sulfonated polyphenylene sulfide （P-S03） by bromination, followed by the substitution of bromine by qua- ternary ammonium group and tertiary amine group. The properties of ampholytic polyphenylene sulfide, such as dissolubility, reduced viscosity, intrinsic viscosity, theological behavior and thermostability, were investigated, and the effects of key factors on performance were studied. The results showed that polar groups on the chain of sulphonated PPS through bromination and the substitution of bromine by quaternary ammonium group and tertiary amine group, make ampholytic PPS soluble in polarity solvent. The viscosi- ties of P-SO3-TMA and P-SO3-DMA have a increasing trend with raising pH. Aqueous solution diluted make mutual attraction between sulfonic acid group and quaternary ammonium group or tertiary amine group weakened, and the conformation becomes loose, leading to reduced viscosity increasing. The ability of monovalent and divalent catonic charges influencing the viscosity of ampholytic polyphenylene sulfide obeys the following sequence： NH4＋ 〈Li＋ 〈Na＋ 〈K＋, Mg^2＋ 〈Ca^2＋, and anions is： CI^- 〈Br^- 〈1^-. In pure water, rheological behavior of ampholytic PPS represents a relatively stable shear rate compared with P-S03. In saturated salt water, the viscosity decreases quickly with increasing shear rate. And its temperature endurance was improved.