کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5205524 | 1502931 | 2017 | 8 صفحه PDF | دانلود رایگان |
Dynamic vulcanization of polylactide (PLA) with castor oil (CO) and three different diisocyanates, namely 4,4â²-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI), was performed to study the effect of diisocyanate type on the vulcanization process and on the morphology as well as mechanical properties of the PLA/CO-based polyurethane blends. The reactivity of the three diisocyanate followed the order of MDIÂ >Â HDIÂ >Â IPDI when reacting with castor oil. Interfacial compatibilization between PLA and the CO-based polyurethane occurred when the less reactive HDI and IPDI was used. Among all the blends, PLA/CO-IPDI showed the finest morphology and the best toughening efficiency. Incorporation of 20Â wt% CO-IPDI increased the elongation at break and notched impact strength of PLA by 47.3 and 6.6 times, respectively. Cavitation induced matrix plastic deformation was observed as the toughening mechanism for the PLA blends with CO-based polyurethane. The effect of CO-IPDI content on the morphology and mechanical properties of PLA was studied in detail. The particle size of dispersed CO-IPDI and the elongation at break increased gradually, the tensile strength and Young's modulus decreased gradually, while the impact strength first increased and then decreased with increasing CO-IPDI content from 5 to 30Â wt%. The maximum impact strength appeared for the blends with 20Â wt% CO-IPDI.
Journal: Polymer Testing - Volume 59, May 2017, Pages 470-477