Comparing crystallization kinetics among two G-resin samples and iPP via Flash DSC measurement

We employed the fast-scan chip-calorimeter Flash DSC1 to compare the non-isothermal and isothermal crystallization kinetics among two G-resin samples (mainly separate in different molecular weights of isotactic polypropylene randomly copolymerized with a few 1-butene in SINOPEC brand MT12-s and MT18-s) and homopolymer isotactic polypropylene (iPP, similar molecular weights). The results show that two G-resin samples crystallize slower than iPP, and their differences in the temperature dependence of crystallization rates reveal the chemical confinement effect of comonomers on polymer crystallization. Furthermore, MT18-s crystallizes slightly faster than MT12-s at low temperatures, which can be attributed to its relatively low molecular weight benefiting a high molecular mobility in the low-temperature region.