聚丁二酸丁二醇酯(pbs)的合成与表征-硕士论文.doc

关于聚丁二酸丁二醇酯（PBS）的合成与表征，该材料为生物降解材料，具有非常好的研发前景。


摘  要

聚丁二酸丁二醇酯(poly butylenes succinate , PBS) 具有良好的生物降解性和机械加工性。但是，高分子量的聚合物合成比较困难而降解速度也较慢。此外，其性能也难以满足各种需要，所以需要对其进行改性。本文则通过共聚来改善PBS性能。
本论文采用钛酸四丁酯为催化剂，合成了具有较高分子量的PBS。研究中发现，PBS中添加一定量芳香族组分精对苯二甲酸（PTA），可以改善其力学性能及降解性能。聚合物的化学结构、分子量和结晶度分别通过核磁共振谱、凝胶色谱和DSC检测。
采用钛酸四丁酯为催化剂，通过熔融缩聚的方法制得高分子量的PBS。PBS合成时酸醇用量比为1/1.2，Ti (OBu)4作为催化剂，用量为0.4% (mol /mol)，预聚合时间为2~3小时，缩聚反应温度控制为 230~240℃，GPC检测显示产物分子量可达到8.85万，通过核磁共振表征并证实了PBS的结构。
以钛酸四丁酯为催化剂，PBST通过直接酯化法合成，主要分三步，首先是BD和SA的直接酯化，其最佳条件按照第二章PBS合成的最佳条件；其次是PTA与BD的直接酯化，反应时间为5h，反应温度为220℃；最后是缩聚反应，反应时间为4h，反应温度为260℃，产物分子量最高可以达到6.80万。随着PTA比例增加，要求缩聚温度提高。GPC检测显示PBST具有较高的分子量。而核磁共振表征并证实了PBST的结构。
比较了PBS与PBST的热力学和力学性能，结果发现在一定含量的T组分存在下，共聚物的分子量虽然稍微有所降低，但是其耐热性提高而且力学性能和脆性都有所改善，初始热分解温度由367.74℃上升到372.95℃，断裂强度由26.15MPa提高到31.76MPa，断裂伸长率由99.43%增加到135.67%。
采用土埋法和特定微生物降解法对PBS和PBST的生物降解性能进行了检测。实验结果显示PBS及PBST在降解过程中，都经历诱导期、加速期两个个阶段，有些能够明显看出平坦期。并且特定微生物降解的速度要大于土埋降解的速度，而在微生物中黑曲霉的降解速度又大于米根霉的降解速度，其28d降解率最高可以达到79.57%。

关键词：聚丁二酸丁二醇酯　聚对苯二甲酸丁二醇酯　共聚物　结构分析　降解
ABSTRACT
Poly butylenes succinate has a good biodegradable and mechanical processing, so it was considered the most promising green wood-polymer as well as PLA. It has been found that molecular weight and crystallinity of the PBS are the key factors which determine the biodegradation of it. It has ever been well thought that it is too difficult to synthesize the high molecular weight PBS. Beside, PBS can not satisfy different requirements as materials,therefore ,in this paper ,the modification of PBS was successfully fulfilled by copolymerization.
Using the compound tetrabutyl titanate catalyst, we successfully synthesized the high molecular weight polymers PBS and its copolymers by polycondensation. Research also found that adding aromatic components PTA to PBS can improve PBS’s mechanical properties and control the effective degradation. Polymer chemical structure, molecular weight and degree of crystallinity was Charactered by 1HNMR,GPC and DSC identification.
Tetrabutyl titanate was used as a catalyst and Synthesis high molecular weight PBS by melt polymerization system. SA to BD is 1/1.2, Ti (OBu) 4 as a catalyst to the amount of 0.4% (mol/mol), and pre-polymerization time is 2 ~3 hours. Polycondensation reaction temperature was controlled between 230 ℃and 240 ℃.GPC tests showed that the molecular weight of PBS is about 89000. In addition, the HNMR characterization confirmed that the structure of the PBS.
Tetrabutyl titanate as a catalyst, we synthesized PBST through direct esterification. The first stage was the direct esterification of BD and SA, and the best conditions in accordance with Chapter 2 of the best conditions of PBS, followed by the PTA and BD direct esterification. The reaction time was about 5 h, and the reaction temperature was to 220 ℃. In the third stage polycondensation reaction time was 4 h, the reaction temperature was to 260 ℃.The highest molecular weight was about 68,000. With the increasing proportion of PTA, condensation temperature should increase. GPC tests showed a higher molecular weight PBST. And NMR characterization confirmed the structure of the PBST.
PBS and PBST were compared with the thermodynamic and mechanical properties. It found that certain components in the presence of T, the molecular weight copolymer although was slightly lower, but the heat of decomposition raised. Beside, the mechanical properties and brittle also improved. Initial thermal decomposition temperature rose to 372.95 ℃from 367.74℃, breaking strength from 26.15 MPa to 31.76 MPa, and elongation raised to 135.67% from 99.43%.
 The biodegradable properties of PBS and PBST were determined by soil Buried and microbial. The experimental results show that PBS and PBST have experienced induction period, accelerated phase two stages in the degradation process,, and some can obviously be found that it had flat period. The degradation speed of Aspergillus niger was greater than the degradation speed of Rhizopus oryzae, while Rhizopus oryzae was greater than landfill, and its degradation rate could reach 79.57% after 28d.

KEYWORDS:  Poly butylenes succinate；Polybutylene terephthalate；Copolymer；Structural analysis；Degradability

 
目  录

摘  要 I
ABSTRACT II
第一章  绪　论 1
1.1文献综述 1
1.1.1降解塑料的研究背景和现状 1
1.1.2降解塑料的分类 2
1.1.3生物降解塑料的分类 3
1.1.4 PBS及PBST的研究 4
1.1.5展望 17
1.2选题的目的和研究内容 17
1.2.1选题目的 17
1.2.2研究内容 18
第二章  PBS的合成与表征 19
2.1引言 19
2.2实验部分 19
2.2.1合成实验部分 19
2.2.2表征实验部分 20
2.3结果与讨论 21
2.3.1分子量 21
2.3.2聚合物结构 25
2.4小结 27
第三章  PBST的合成与表征 28
3.1引言 28
3.2实验部分 28
3.2.1试剂与仪器 28
3.2.2合成实验步骤 29
3.2.3 PBST的表征 29
3.3结果与讨论 29
3.3.1分子量 29
3.3.2聚合物组成 31
3.4小结 34
第四章  PBS和PBST的性能比较 35
4.1前言 35
4.2实验部分 35
4.2.1实验仪器 35
4.2.2实验步骤 35
4.3结果与讨论 37
4.3.1分子量 37
4.3.2热力学性能 38
4.3.3力学性能 41
4.4小结 42
第五章  PBS与PBST的降解性实验 43
5.1引言 43
5.2 实验部分 43
5.2.1实验试剂和仪器 43
5.2.2实验菌种 44
 
5.2.3样品性能规格 44
5.2.4薄膜的制备 44
5.2.5微生物培养液的配制 45
5.2.6实验步骤 45
5.3结果与讨论 46
5.3.1 PBS的生物降解性 46
5.3.2 PBST的生物降解性 49
5.4小结 54
第六章  结论与展望 56
6.1结论 56
6.2课题展望以及进一步需要开展的工作 57
参考文献 58
硕士论文期间所获成果 65
致  谢 66