摘要

Free-radical grafting of ternary-monomer onto polypropylene (PP) particles in the solid state has been studied using supercritical carbon dioxide (SC CO2) as a solvent and a swelling agent. The PP particles were first swelled with the monomers and AIBN as an initiator, using SC CO2 at different experimental conditions of pressure, temperature and treatment time. After releasing CO2, monomers were grafted onto PP in different temperatures. During monomer selection, combination of soft monomer and hard monomer was used in order to tune polarity and flexibility of grafted polymer. FTIR spectra confirmed that ternary-monomer had been grafted onto PP and SEM showed that grafted molecules had been uniformly distributed in the PP substrate. TG analysis indicated that thermal stability of grafting modified PP had been improved, and DSC revealed that grafting leads to a lower degree of crystallinity of polypropylene.

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