There are many classification methods of PPS. According to the molecular weight, PPS can be divided into high, medium and low molecular weight resins. According to the structure and composition, PPS can be divided into branched chain type, straight chain type and modified resin. At present, the market is often divided into injection grade, coating grade and fiber grade according to their application. This paper focuses on the first two types.
The processing performance of injection grade PPS is outstanding, which can improve the dimensional stability and reduce the molding shrinkage. Injection grade PPS is widely used in electrical and electronic field, material manufacturing industry and chemical industry. It is mainly used to make precision electrical connectors, high temperature resistant contactors, high temperature resistant electrical parts, insulating electrical parts and anti-corrosion sealing parts.
Coating grade PPS has the characteristics of high temperature resistance, radiation resistance and chemical resistance. Because there are two lone pair electrons on the sulfur atom of PPS molecule, it has strong adhesion with metal. It is not necessary to spray primer during construction, but only need to add part of fluorine resin to improve its wear resistance and non adhesion. Coating grade PPS can be sprayed by electrostatic spraying, thermal spraying and suspension spraying.
Coating grade PPS is widely used in mechanical engineering, which can improve the interface bonding between fiber and PPS, and improve the high temperature boiling resistance of the composite under the same conditions. Ouyang energy et al. Explained the micro mechanism of PPS reinforced by aramid fiber by molecular mechanics calculation: after the introduction of epoxy group on aramid fiber, the electrostatic interaction and van der Waals force of the composite system were improved, and the total energy of the interface system decreased significantly, which indicated that the mutual attraction of the two components increased and the structural stability of the interface was improved.