首页 | 本学科首页   官方微博 | 高级检索  
     


Synthesis and characterizations of poly(ethylene-co-vinylalcohol)-grafted-poly(3-hydroxybutyrate-co-hydroxyvalerate) copolymers
Authors:Tarik Sadik  Valérie Massardier  Frédéric Becquart  Mohamed Taha
Affiliation:1. Université de Lyon, F-42023, France;2. CNRS, UMR 5223, France;3. IMP@UJM, Université de Saint Etienne, Jean Monnet, F-42023, Saint Etienne, France;4. INSA-Lyon, IMP, UMR5223, Université de Lyon, F-69621 Villeurbanne, France
Abstract:Poly(ethylene-co-vinylalcohol)-grafted-poly(3-hydroxybutyrate-co-hydroxyvalerate) (EVOH-g-PHBV) was prepared by a catalyzed grafting of PHBV onto immiscible EVOH. These reactions were performed at high temperature in the molten state. The choices of Tin(II) bis(2-ethylhexanoate) (Sn(Oct)2) and 1,5,7-Triazabicyclo4.4.0]dec-5-ene (TBD), as catalyst, were justified by a first study in an internal mixer. The catalyst quantity, reaction temperature and reaction time were optimized to apply them in the conditions of a reactive extrusion process with a co-rotating twin screw extruder. High reaction temperature, from 180 °C to 220 °C, associated to intensive mixing led to efficient grafting of PHBV onto EVOH, compatible with short residence times required.Rheological, thermal and morphological analyses were conducted to characterize the obtained copolymers. Molecular weights were determined by SEC. SEM imaging were made on cryo-fractured surfaces of blends extruded with and without catalyst. In most of reaction conditions, a compatible blend was obtained with a fine micro phase separation. Grafted copolymers were only obtained when well defined and controlled conditions are applied.
Keywords:
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号