In situ polymerization of starch with lactic acid in aqueous solution and the microstructure characterization

被引:72
作者
Gong, Qingxia [1 ]
Wang, Li-Qun [1 ]
Tu, Kehua [1 ]
机构
[1] Zhejiang Univ, Inst Polymer Sci, Hangzhou 310027, Peoples R China
关键词
starch; poly(lactic acid); relative reactivity; degree of substitution; degree of polymerization; C-13 magnetic resonance;
D O I
10.1016/j.carbpol.2005.09.005
中图分类号
O69 [应用化学];
学科分类号
081704 ;
摘要
Copolymers of starch grafted with poly (lactic acid) were directly prepared by in situ reaction of cornstarch with lactic acid in aqueous media in the presence of stannous 2-ethyl hexanoate [Sn(Oct)(2)]. The procedure of the graft reaction was elucidated, based on the HPLC analysis, as the ring-opening polymerization (ROP) from starch surface of the small amounts of lactide produced in situ in the reaction system. The detailed chemical microstructure of the resultant graft copolymer was clarified by one- and two-dimensional NMR spectroscopy. Analysis of C-13 NMR spectra of the carbons in starch ring as well as the carbonyl carbons in LA moiety demonstrates that the reactivity of hydroxyl groups at glucopyranan unit of starch decreases in the order of C-6 > C-3 > C-2. The average length of PLA grafts at individual starch ring carbons was also investigated. (c) 2005 Elsevier Ltd. All rights reserved.
引用
收藏
页码:501 / 509
页数:9
相关论文
共 33 条
[21]  
Mani R, 1998, MACROMOL RAPID COMM, V19, P283, DOI 10.1002/(SICI)1521-3927(19980601)19:6<283::AID-MARC283>3.3.CO
[22]  
2-3
[23]   ONE-DIMENSIONAL NUCLEAR-MAGNETIC-RESONANCE STUDIES OF STARCH AND STARCH PRODUCTS [J].
MCINTYRE, DD ;
HO, C ;
VOGEL, HJ .
STARCH-STARKE, 1990, 42 (07) :260-267
[24]   Determination of the degree of branching in normal and amylopectin type potato starch with H-1-NMR spectroscopy - Improved resolution and two-dimensional spectroscopy [J].
Nilsson, GS ;
Bergquist, KE ;
Nilsson, U ;
Gorton, L .
STARCH-STARKE, 1996, 48 (10) :352-357
[25]   Graft polymerization of L-lactide on pullulan through the trimethylsilyl protection method and degradation of the graft copolymers [J].
Ohya, Y ;
Maruhashi, S ;
Ouchi, T .
MACROMOLECULES, 1998, 31 (14) :4662-4665
[26]   Modification of polylactide upon physical properties by solution-cast blends from polylactide and polylactide-grafted dextran [J].
Ouchi, T ;
Kontani, T ;
Ohya, Y .
POLYMER, 2003, 44 (14) :3927-3933
[27]   OBSERVATIONS ON NMR-SPECTRA OF STARCHES IN DIMETHYLSULFOXIDE, IODINE-COMPLEXING, AND SOLVATION IN WATER DIMETHYLSULFOXIDE [J].
PENG, QJ ;
PERLIN, AS .
CARBOHYDRATE RESEARCH, 1987, 160 :57-72
[28]   CONFIGURATIONAL AND CONFORMATIONAL INFLUENCES ON C-13 CHEMICAL SHIFTS OF SOME CARBOHYDRATES [J].
PERLIN, AS ;
CASU, B ;
KOCH, HJ .
CANADIAN JOURNAL OF CHEMISTRY, 1970, 48 (16) :2596-&
[29]   Rapid preparation of starch esters by high temperature/pressure reaction [J].
Shogren, RL .
CARBOHYDRATE POLYMERS, 2003, 52 (03) :319-326
[30]   Cellulose diacetate-graft-poly(lactic acid)s:: synthesis of wide-ranging compositions and their thermal and mechanical properties [J].
Teramoto, Y ;
Nishio, Y .
POLYMER, 2003, 44 (09) :2701-2709