Structure-property relationships of lightly chemical crosslinked poly(vinyl chloride) thermoplastic elastomer

Abstract

Chemical crosslinked poly(vinyl chloride) (C-PVC) was synthesized by vinyl chloride suspension polymerization in the presence of diallyl phthalate (DAP) and plasticized to prepare poly(vinyl chloride) (PVC) thermoplastic elastomer (TPE) materials. The chemical crosslinking and physical crosslinking structure in chemical crosslinked PVC-TPE were investigated. It showed that the gel fraction and the crosslinking density of gel increased as the feed concentration of DAP increased. C-PVC prepared by VC/DAP copolymerization was lightly crosslinked as compared with irradiation crosslinked PVC. Physical entanglements would greatly influence the crosslinking density of gel when the gel fraction was high. Chemical crosslinking had little influence on the recrystallization behavior of PVC. A structure model of chemical crosslinked PVC-TPE was proposed, in which chemical networks acted with physical networks cooperatively. It also showed that chemical crosslinking and physical crosslinking influenced the processability and mechanical properties of chemical crosslinked PVC-TPE cooperatively. Although the processability of PVC-TPE deteriorated with chemical crosslinking, the dimension stability and elasticity of PVC-TPE were improved as the permanent chemical networks were introduced.

Synthesis of amphiphilic PVC-b-poly(hydroxypropyl acrylate) (PHPA)-b-PVC block copolymers with low PHPA contents and different molecular weights by (Single Electron Transfer)-(Degenerative Chain Transfer) living radical polymerization

“…Figure shows DSC thermograms for the COP45 block copolymer sample, its gel fraction, and a PVC reference sample (S950). In agreement with the findings of Bao et al , the results obtained for lightly crosslinked PVC products, from materials analyzed as a whole, show differences that are due to the presence of crystallites that cannot be easily detected in the DSC profile. Fractionation of the block copolymer allows separation of the gel fraction to take place.…”

“…The presence of a crosslinked fraction in PVC can be identified by determining its gel fraction . The synthesized PVC‐b‐PHPA‐b‐PVC block copolymers had a fraction insoluble in THF.…”

High activated carbon loading mixed matrix membranes for gas separations

“…Distinct advantages arising from PVC plasticization are low cost, versatile processing of various shapes and designs [23], which make soft PVC the main alternative to replace flexible products based on elastomers or leather. The main limitations in the application of soft PVC come from its poor thermal and chemical resistance properties [24,25]. Crosslinking soft PVC by using a crosslinking agent is the most effective way to improve thermal and transport properties of flexible PVC.…”

Crosslinked PVC polymerization: Study on process dependencies

“…There is also some research about the crosslinked PVC polymerization. Recently, Bao et al and Luo et al8–12 have shown an active investigation about crosslinking of PVC during polymerization reaction and published a series of articles about their results. Those results were invaluable especially in that they set up the detailed theoretical background about the crosslinked PVC polymerization which had remained out of researchers' interest for so long.…”