以D,L乳酸为原料，氯化亚锡(SnCl2)与萘二磺酸(NDA)为催化剂体系，熔融缩聚制备聚乳酸，并采用旋光度法、1HNMR和13CNMR核磁共振法、X射线衍射和黏度法等研究萘二磺酸对聚乳酸微结构的影响。SnCl2和NDA分别催化D,L乳酸聚合可制备消旋的非晶态聚乳酸，而SnCl2/NDA催化体系所得的聚乳酸是高光学活性的L构型的结晶聚合物。SnCl2/NDA催化体系具有高度的立构选择性，且SnCl2与NDA配比及其用量对聚乳酸的光学活性、分子链的构型、链段序列分布和晶体结构等微结构均有明显的影响。当SnCl2质量分数为0.5%、n(SnCl2)/n(NDA)为1∶1时，D,L乳酸熔融缩聚可制备光学纯度97.4%的高光学活性的L型聚乳酸。
Abstract
Polys (lactic acid) was prepared from D,Llactic acid through melt polycondesation. Viscometry, polarimetry, 1HNMR, 13CNMR and XRD were performed to detect poly(lactic acid) (PLA) samples. PLA with excessive Lonformation units in polymer chains can be obtained using SnCl2 and naphthalene disulphonic acid (NDA) as catalyst system. Ratios of SnCl2 and NDA and its contents affected the opitical purities of PLAs, PLA microstructures of chains and cryticals. When SnCl2 content was 0.5% and n(SnCl2)/n(NDA) 1∶1, PLA with opitical purity 97.4% was then obtained from D,Llactic acid.
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1]Robert J L, Aubrecht K B. Green chemistry: Ringopening polymerization of lactide to form a biodegradable polymer[J]. J Chem Edu, 2008, 85(2): 258-260.
[2]Platel R H, Hodgson L M, Williams C K. Biocompatible initiators for lactide polymerization[J]. Polym Rev, 2008, 48(1): 11-63.
[3]Tang Z H, Yang Y K, Pang X, et al. Controlled and stereospecific polymerization of raclactide with a singlesite ethyl aluminum and alcohol initiating system[J]. J Appl Polym Sci, 2005, 98(1): 102-108.
[4]高勤卫,李明子,董晓. 聚乳酸的立构选择性聚合的研究进展[J]. 现代化工,2007,27(10):20-24.
[5]高勤卫,李明子,董晓. D,L乳酸的立构选择性聚合[J]. 南京林业大学学报:自然科学版,2008,32(3):43-47.
[6]董晓. 聚乳酸的立构选择性聚合研究[D]. 南京:南京林业大学,2007.
[7]Gao QW, Lan P, Shao H, et al. Direct synthesis with melt polycondensation and microstructure analysis of poly (Llactic acidcoglycolic acid)[J]. Polym J, 2002, 35(11): 786-790.
[8]Spassky N, Wisniewski M, Pluta C, et al. Highly stereoelective polymerization of rac(D,L)lactide with a chiral Schiff’s base /aluminium alkoxide initiator[J]. Macromol Chem Phys, 1996, 197: 2627-2637.
[9]Akihiro Ando, Kunio Kimura, Yuko Onda, et al. New attempt at the stereoselective polymerization of lactide by using crystallization during polymerizaion[J]. Macromolecular Rapid Communications, 2005, 26: 98-102.
[10]Choi E J, Park J K, Chang H N. Effect of polymerization catalysts on the microstructure of poly (LLAcoεCL)[J]. J Polym Sci Part B: Polym Phys, 1994, 32: 2481-2489.
[11]Esoartero J L, Manolova S M, Manolova N, et al. NMR analysis of low molecular weight poly(lactic acid)s[J]. Macromoleculars, 1996, 29: 3535-3539.
[12]Svhindler A, Harper D J. Poly(lactic acid) I stereosequence distribution in the polymerization of racemic dilactide[J]. Polym Sci: Polym Lett, 1976, 14: 729-734.
[13]Chamberlain B M, Cheng M, Moore D R, et al. Polymerization of lactide with zinc and magnesium betadiiminate complexes: stereocontrol and mechanism[J]. J Am Chem Soc, 2001, 123(14): 3229-3238.
[14]Coates Geoffrey W, Ovitt Tina M. Stereoselective ringopening polymerization of lactide: Synthesis of syndiotactic and heterotactic poly(lactic acid)s[C]//Book of Abstracts, 219th ACS National Meeting, San Francisco, CA, 2000.
[15]Kricheldorf H R, and Sumbel M. Polylactones18 polymerization of L,Llactide with Sn(Ⅱ) and Sn(Ⅳ) halogenides[J]. Eur Polym, 1989, 25: 585-591.
基金
收稿日期：2008-08-29修回日期：2009-02-18基金项目：国家自然科学基金资助项目(50573032)作者简介：高勤卫(1968—)，副教授，博士，研究方向为生物高分子材料、环境友好高分子材料、高分子物理与化学。Email: Qinway_gao@yahoo.com.cn。引文格式：高勤卫,何刚,李明子,等. 氯化亚锡/萘二磺酸对D,L乳酸聚合物微结构的影响[J]. 南京林业大学学报:自然科学版,2009,33(3):111-115.
PDF(636922 KB)
