Environment-friendly synthesis of amphiphilic polyester-graft-poly(vinyl alcohol)

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• 作者：Nadia Guerrouani ; Benoit Couturaud ; André ; Mas ; ^{andre.mas02@univ-montp2.fr} ; Franç ; ois Schué ; Jean-Jacques Robin
• 关键词：Graft copolymers ; Amphiphilic copolymers ; Ring opening polymerization (ROP) ; Poly(vinyl alcohol) ; Poly(l-lactide)
• 刊名：European Polymer Journal
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：49
• 期：6
• 页码：1621-1633
• 全文大小：974 K

文摘

Experimental conditions for the synthesis of poly(¦Å-caprolatone)-graft-poly(vinyl alcohol) (PCL-g-PVA) and poly(l-lactide)-graft-poly(vinyl alcohol) (PLLA-g-PVA) via a PVA/MgH₂ macroinitiator were optimized. Heat stability of PVA (99 % hydrolyzed) in l-lactide (L-LA) melt was studied by DSC, TGA to lower the reaction temperature and time in order to avoid degradation. Thus, no degradation of copolymers occurred and ¹³C NMR study showed that l-lactide was incorporated in graft chains as isotactic poly(l-lactide) without racemisation for 140-160 ¡ãC, up to 25 h, L-LA/PVA ratio in the range 3-12. Such synthesis using non-toxic catalyst and reactants in a solvent-free medium can be described as environment-friendly. Amphiphilic behavior of copolymers was studied in aqueous solution according to their chemical structures: critical micelle concentration CMC (0.03-0.5 g L^?1), average diameter of micelles (80-150 nm), surface tension ¦Ã_CMC (46-63 mN m^?1), hydrophilic to lipophilic balance HLB (Griffin definition 4-7), and also from cast films: surface energy ¦Ã_s (36-50 mJ m^?2). This environment-friendly process is suitable for the use of graft PVA copolymers in biomedical area for investigations under micelle applications.