Poly(phenylene sulfide) and low-density polyethylene reactive blends. Morphology, tribology, and moldability

Morphology, tribology, and moldability of poly(phenylene sulfide) (PPS) and low density polyethylene (LDPE) reactive blends were investigated. Tribological properties (friction and wear) are synergistically improved in the blends of PPS/LDPE (90/10 by weight). However, the simple blending of PPS/LDPE give rise to the deposition on the mold surface in the cyclic operation of injection molding, which causes poor surface appearance of mold articles and leads to poor productivity. Glycidyl functional materials work as coupling agents between the PPS matrix and the domains of LDPE grafted with maleic anhydride (LDPEgMA) during melt mixing, resulting in the reduction of the domain size. It was found that introduction of the coupling reaction between PPS and LDPEgMA prevents the mold deposition (MD), whereas the good tribological properties are maintained. Furthermore, notched izod impact strength is increased, and then, specific balanced combination of physical and thermal properties can be achieved. Morphological analysis was performed by electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS) on an energy-filtering transmission electron microscope (EFTEM). It was revealed that the LDPE domains are not encapsulated by the glycidyl functional materials, but those two phases are stuck together. It was concluded that the preferable properties were achieved owing to the synchronization of the each three phase, i.e., PPS, LDPE, and the glycidyl functional material's phases, by taking the stuck phase formation.