Synthesis and characterization of compatibilizers for blends of polypropylene carbonate and polybutylene succinate via free‐radical grafting of maleic anhydride

Abstract

This study focuses on creating an optimal grafting compatibilizer for blends of polypropylene carbonate (PPC) and polybutylene succinate (PBS). PPC and PBS were blended separately with different amounts of maleic anhydride (MAH) and with and without dicumyl peroxide (DCP) to aid the free-radical grafting. Titration analysis evidenced that MAH reacted with the polymers terminal groups and backbones using free-radical functionalization. Thermogravimetric analysis (TGA) and gas permeation chromatography (GPC) results demonstrated how the thermal stability of PPC improves with the addition of MAH. Proton NMR proved that, in both PPC and PBS formulations, ring-opening reactions and grafting of the intact MAH ring occur, as well as interchain grafting producing network structures. The rheological analysis showed that small quantities of MAH and DCP increase the viscosity of the resins. The compatibilizer that was determined to be most reactive and stable of all the formulations analyzed was PPC with 2% MAH and DCP and its effect in the morphology of PPC-PBS blends was proven successful by a reduction of the PPC droplet size.

Preparation and rheological study of pentaerythritol triacrylate grafted onto polypropylene induced by air plasma

“…One is that the melt grafting requires much less time, around tens of minutes, than hours in solution or vapor phase grafting . The other is that melting grafting achieves the modification of polymer bulk, more efficient than the only surface modification in solution grafting and vapor phase grafting . There are few reports on the melt grafting modification of materials by plasma‐induced polymerization.…”

Kinetic Model of Maleic Anhydride Grafting onto Poly(Propylene Carbonate) during Melt Compounding

“…Also, dissolution studies on the same samples showed that there was no crosslinking in the system due to the DCP action. Moreover, the amount of potential inner chain grafting was assumed to be very small based on the NMR results found in the previous work . Termination by disproportionation was considered significant.…”

“…This process involves the thermal decomposition of the peroxide into free radicals that can abstract hydrogens from the polymer backbone to induce reaction with MAH. Also, maleic anhydride can undergo esterification reaction with the OH groups of PPC leaving maleic acid end groups, which can further react in the system and also make PPC more thermally stable …”

“…Our previous works describe a detailed examination of the melt compounding of PBS and PPC with varying amounts of MAH and a peroxide initiator. The chemical structure of the compounds, the amount of grafting (grafting efficiency) in the formulations and the potential reaction routes of the system were characterized by means of NMR, FTIR, rheology, titration tests, GPC, and TGA measurements . Moreover, it was found that PPC‐grafted‐MAH (gPPC) increases the strain at break and impact strength of PPC and PBS blends considerably .…”

“…The present work aims to create a model that can properly predict the amount of grafting of PPC‐grafted‐MAH with varied amounts of MAH and peroxide. The kinetic scheme considered is based on the analysis made in the previous studies and other works on free radical grafting of PP aided by peroxide . The purpose is to investigate this reaction scheme further and provide quantitative data of the grafting mechanism and performance prediction.…”