Aliphatic polyester-grafted starch-like polysaccharides by ring-opening polymerization
- 作者：Dubois ; Philippe ; Krishnan ; Mohan ; Narayan ; Ramani
- 关键词：Aliphatic polyester ; Polycaprolactone ; Polysaccharide
- 刊名：Polymer
- 出版年：1999
- 期刊代码：83_00323861
- 类别：ms
- 出版时间：May, 1999
- 卷：40
- 期：11
- 页码：3091-3100
- 文件大小：949 K
摘要
This paper reports on the synthesis of aliphatic polyester-grafted starch by in situ ring-opening polymerization (ROP) of ε-caprolactone in the presence of starch-like polysaccharides that may be granular or plasticized, or a mixture of these, wherein the in situ ROP is conducted in the bulk, i.e. in the absence of solvents. The polymerization is initiated from the starch phase with the amylose/amylopectin hydroxyl functions in the presence of a catalyst such as Sn(Oct)2, or by adequate modification/activation of the surface hydroxyls into titanium or aluminium alkoxides, thereby promoting grafting and good interfacial adhesion between the two starch/polycaprolactone (PCL) phases. Evidence for coupling of the active initiator species onto the starch hydroxyls, aluminium alkoxides for instance, is shown by an aluminium peak in the X-ray photoelectron spectroscopy scan of a starch surface reacted with triethylaluminium. Good interfacial adhesion is confirmed by scanning electron microscopy images of surface fractures and by selective extraction experiments in toluene, which is a good solvent for solubilizing the non-grafted PCL chains.