Influence of crosslinking density of poly(butylacrylate) backbone on processibility of poly(vinylchloride) grafted onto poly(butylacrylate)

Abstract

Graft copolymers of vinyl chloride onto poly(butylacry1ate) with alternating amount of diallylphthalate crosslinker (PBA-g-VC) have been synthesized by suspension polymerization. Taking into account different crosslinking density of PBA, the processing behaviour of PBA-g-VC was studied with a Brabender Plasticorder and a viscoelastometer. The experimental results showed that, with increasing crosslinking density of PBA, the processing behaviour of PBA-g-VC improved initially, then reached an optimum and finally declined with further increase in crosslinking density of the backbone. Based on the results of viscoelastometer measurement, the mechanism of change of processibility of graft copolymer is discussed. ZUSAMMENFASSUNG:Vinylchlorid (VC) wurde durch Emulsionspolymerisation auf mit wechselnden Mengen Diallylphthalat vernetztes Polybutylacrylat (PBA) gepfropft. Das Verarbeitungsverhalten der Pfropfprodukte (PBA-g-VC) wurde unter Berucksichtigung der unterschiedlichen Vernetzungsdichte des PBA mit einem Brabender-Plasticorder und einem Viskoelastometer untersucht. Mit zunehmender Vernetzungsdichte verbesserte sich zunachst die Verarbeitbarkeit, erreichte ein Maximum und nahm mit weiter steigender Vernetzungsdichte der Pfropfgrundlage wieder ab. Auf der Grundlage der Ergebnisse der Viskoelastometermessungen wird der Mechanismus der Anderung der Verarbeitbarkeit der Copolymeren diskutiert.

Synthesis and characterization of poly(butyl acrylate‐co‐ethylhexyl acrylate)/ poly(vinyl chloride)[P(BA‐EHA)/PVC] novel core‐shell modifier and its impact modification for a poly(vinyl chloride)‐based blend

“…This implies that adding the P(BA-EHA)/PVC modifier improves the processing properties of PVC. The aforementioned results are completely in agreement with general findings, that one of the roles of crosslinked PBA graft copolymers has an effect of a processing aid [8,24].…”

“…After that, only one torque peak occurs, corresponding to the beginning of the primary particle fusion process, and this torque value at the peak is called the maximum torque, whereas the time needed from compaction to the occurrence of the maximum is called the plastication time. When the fusion process approaches completion, the torque reaches equilibrium [24].…”

“…In general, the lower the glass transition temperature of a processing aid is, the better is the processability of PVC blends with that processing aid [24]. The differences in processability of the PVC blends are attributed to the different ''granule-adhering'' and ''particle-destroying'' abilities of the P(BA-EHA)/PVC modifiers with a change of the crosslinked P(BA-EHA) and grafting copolymer content.…”

Preparation and characterization of poly(butyl acrylate‐co‐2‐ethylhexyl acrylate) grafting of vinyl chloride resin with good impact resistance

“…P(BA–EHA)‐grafted VC resin is substantially a mixture which is composed of the homopolymer of PVC, crosslinked P(BA–EHA), and the P(BA–EHA)‐grafted VC copolymer. So, the determination of the GE requires separating the PVC homopolymer from the P(BA–EHA)‐grafted VC resin 11–13. This is achieved by extraction with tetrahydrofuran, which removes the PVC which is not grafted onto P(BA–EHA), but the crosslinked P(BA–EHA) and its grafted VC copolymer remain.…”

Melt grafting of n‐butyl methacrylate onto poly(vinyl chloride): Synthesis and characterization*

“…The graft copolymerization can be carried out in two ways: solution polymerization process or melt processing during mixing/extrusion process. Many authors have reported the solution polymerization route of modification of PVC with a monomer in a suitable solvent, to improve the thermal stability, processibility, or impact strength of PVC 8–14. However, this method has inherent drawbacks, such as requiring a large quantity of solvent and its removal after the reaction, and remains in the realm of academic interest, although it is not commercially feasible.…”