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Grafting of poly(vinyl chloride) and polypropylene with styrene in a supercritical CO 2 solvent medium: Synthesis and characterization
Author(s) -
Trivedi Akshay H.,
Kwak Soonjong,
Lee Sunggyu
Publication year - 2001
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10889
Subject(s) - copolymer , materials science , polymer chemistry , styrene , thermogravimetric analysis , vinyl chloride , polystyrene , radical initiator , monomer , supercritical fluid , differential scanning calorimetry , polypropylene , solvent , polymer , chemistry , organic chemistry , composite material , physics , thermodynamics
Graft copolymerization of styrene onto poly(vinyl chloride) (PVC) and polypropylene (PP) was carried out in a supercritical CO 2 medium using AIBN as a free radical initiator. The supercritical CO 2 medium served as a reaction medium in addition to being a solvent for the styrene monomer and the free radical initiator. The reaction temperature and pressure were kept above the critical points of the solvent‐monomer mixture to form a homogeneous single‐phase medium. The resulting graft copolymers were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and nuclear magnetic resonance (NMR) techniques. The weight percent of grafting was determined using IR absorbance ratio technique. TGA results showed that the thermal stabilily of grafted copolymer of PVC was better than that of PVC, while grafted copolymer of PP had poorer thermal stability than PP. DSC results showed that glass transition temperatures (T g 's) of the grafted copolymers were higher than those of the starting polymers PVC and PP. The presence of polystyrene attached to the backbone polymer was confirmed by 1 H NMR and 13 C NMR analyses.