Abstract
Crystallization kinetics of various blends of poly(lactic acid) (PLA)/polyolefin elastomer (POE) was studied through nonisothermal experimental investigations and theoretical approaches. The PLA/POE blends were prepared in a melt mixing process by using two types of POEs and compatibilizers. The rubber phases used were adopted on the basis of polyethylene (PE) and polypropylene (PP) type olefin elastomers. The effects of two kinds of compatibilizers containing ethylene vinyl acetate copolymer (EVA) and ethylene acrylic ester-glycidyl methacrylate terpolymer (EGMA) on the morphology and various parameters of crystallization of PLA were investigated using scanning electron microscopy (SEM) and differential scanning calorimeter (DSC) measurements, respectively. The morphology investigations on PLA blends containing PP based olefin elastomers showed that the introduction of EGMA compatibilizer into the matrix led to a more than 100% reduction in the size of the rubber droplets. The experimental measurements of crystallization behavior of various PLA/POE blends showed that the POEs and compatibilizers could cause a fall in the initial crystallization temperature more than 13 °C. The theoretical approaches used for studying the kinetics of crystallization of PLA in the presence of various POEs and compatibilizers indicated a decrease in the crystallinity of PLA and a 64% reduction in the activation energy compared to the neat PLA. The results suggest that the largest variation in the crystallization kinetic parameters of PLA was resulted from the PP based olefin elastomer and EGMA compatibilizer.
Highlights
The mechanical behavior of polymers is greatly influenced by their thermal properties [1] and thermal histories [2], which can be determined experimentally [3]
CaroinouclsuPsiLoAns/polyolefin elastomer (POE) blends were prepared via melt mixing process and the effects of POE type, and comVpaatriiboiuliszePrLtAy/pPeOwEebrelemndosniwtoerreedpurseipnagrecdryvstiaalmlizealttiomnixkiinngetpicropcaersasmaentdertshoefetfhfeecPtsLoAf mPOatErixty. pe, Asseasnsdmceonmtspmataibdielizoenrmtyoprephwoelroegmy ionnditiocareteddutshiantgthcreypstraelsleiznacteioonf kEiGnMetiAc paasraamcoemteprsatoibf itlhizeePr LhAadmaantrix. effecAtisvseesrsomleeinntsthmeaddiestorinbumtioornphoof ltohgeyPiOndEipcahtaesdetihnatthtehePLpAresmenatcreixo,feEspGeMciAallaysian cbolemnpdasticboinlitzaeirnihnagd an effective role in the distribution of the POE phase in the Poly(lactic acid) (PLA) matrix, especially in blends containing a PP base POE
The resulting differential scanning calorimeter (DSC) diagrams indicated that the initial crystallization temperature of the PLA matrix shifted to a lower temperature with the introduction of various POEs into the PLA matrix, and the addition of a a PP base POE
Summary
The mechanical behavior of polymers is greatly influenced by their thermal properties [1] and thermal histories [2], which can be determined experimentally [3]. Wu et al [25] reported on the effect of the olefin block copolymer on the toughness strength and mechanical properties of PLA in the presence of a compatibilizer and found that the elastomer phase could enhance the impact toughness of PLA up to 25 times compared to the neat PLA. Their study showed that there was a chemical interaction between PLA and EGMA, while only physical interaction occurred between the olefin block copolymer (OBC) and EGMA, which led to an asymmetric dispersed phase morphology Their results indicated that the crystallization behavior of PLA depends on both the content of the dispersed phase and the type of the second polymer used in the blend. The effects of various compatibilizers on the morphology of the prepared PLA/POE blends were evaluated by scanning electron microscopy (SEM) and the size of the dispersed rubber phase was calculated using statistical analysis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
