Poly(butylene succinate)/poly(vinyl phenol) blends. Part 1. Miscibility and crystallization

Miscibility has been investigated in blends of poly(butylene succinate) (PBSU) and poly(vinyl phenol) (PVPh) by differential scanning calorimetry in this work. PBSU is miscible with PVPh as shown by the existence of single composition dependent glass transition temperature over the entire composition range. In addition, the polymer–polymer interaction parameter, obtained from the melting depression of PBSU using the Nishi–Wang equation, is composition dependent, and its value is always negative. This indicates that PBSU/PVPh blends are thermodynamically miscible in the melt. Preliminary morphology study of PBSU/PVPh blends was also studied by optical microscopy (OM). OM experiments show the spherulites of PBSU become larger with the PVPh content, indicative of a decrease in the nucleation density, and the coarseness of PBSU spherulites increases too with increasing the PVPh content in the blends.     

新法合成1，4－二羟基－2－萘甲酸

新法合成１，４ 二羟基 ２ 萘甲酸，操作简便，溶剂消耗少，反应时间短，收率高。探索了影响反应产率的几种因素。     

硫酸氢钠催化合成丁二酸二乙酯

在一水硫酸氢钠存在下 ,由乙醇和丁二酸合成了丁二酸二乙酯。当丁二酸、乙醇和硫酸氢钠的物质的量比为 1∶ 6∶ 0 .2 ,环己烷为溶剂 ,回流分水 5 0 m in,酯收率达 80 .5 %     

全生物降解PBS的扩链改性研究

采用新型扩链剂2,2′-双(2-噁唑啉)(BOZ)对聚丁二酸丁二醇酯(PBS)进行扩链,研究了BOZ加入量、稳定剂加入量、时间、温度对扩链反应的影响。结果表明,选择最佳条件,扩链后的PBS的相对分子质量较未扩链PBS的相对分子质量大为增加,而且扩链PBS相对分子质量分布与未扩链PBS基本一致,说明PBS扩链后的线性度与起始PBS相同,没有支化或交联反应发生。     

DSC and TMDSC study of melting behaviour of poly(butylene succinate) and poly(ethylene succinate)

The subsequent melting behaviour of poly(butylene succinate) (PBSU) and poly(ethylene succinate) (PES) was investigated using DSC and temperature modulated DSC (TMDSC) after they finished nonisothermal crystallization from the melt. PBSU exhibited two melting endotherms in the DSC traces upon heating to the melt, which was ascribed to the melting and recrystallization mechanism. However, one melting endotherm with one shoulder and one crystallization exotherm just prior to the melting endotherm were found for PES. The crystallization exotherm was ascribed to the recrystallization of the melt of the crystallites with low thermal stability, and the shoulder was considered to be the melting endotherm of the crystallites with high thermal stability. The final melting endotherm was ascribed to the melting of the crystallites formed through the reorganization of the crystallites with high thermal stability during the DSC heating process. TMDSC experiments gave the direct evidences to support the proposed models to explain the melting behaviour of PBSU and PES crystallized nonisothermally from the melt.     

聚丁二酸丁二醇酯/纤维素纳米晶复合纤维增强机制

采用熔融纺丝法制备了聚丁二酸丁二醇酯(PBS)/纤维素纳米晶(CNC)复合纤维,重点研究了CNC的分散性、PBS与CNC间氢键作用、PBS分子取向、CNC沿轴向排布以及PBS相结晶度对复合纤维强度的影响。通过光学显微镜和场发射扫描电镜观察发现:高牵伸倍率下的复合纤维较低牵伸倍率下的复合纤维侧面更加平整、光滑,且高牵伸倍率下CNC列。红外光谱图证实了PBS与CNC用力。此外,在提高牵伸倍率时,PBS复合纤维结晶度增大,并且其声速值也明显提高。多因素协同导致PBS/CNC(质量比99/1)复合纤维经4倍牵伸后断裂强度达3.59 cN/dtex,远高于相同处理条件下的纯PBS纤维。     

生物降解材料在水环境中降解性能的研究进展

综述了目前典型生物降解材料在水环境中降解性能的研究现状,详细介绍了聚乳酸（PLA）高分子材料（PLA、PLA共聚物、PLA复合材料等）、聚羟基烷酸酯（PHA）、聚己内酯（PCL）、聚丁二酸丁二醇酯（PBS）、聚（己二酸丁二醇酯?对苯二甲酸乙二醇酯）（PBAT）和CO₂共聚物等在不同水环境中的降解性能;最后总结了生物降解材料未来需要关注的问题和发展方向。     

Synthesis, characterization, and properties of poly(ethylene terephthalate)/poly(1,4-butylene succinate) block copolymers

Reactive blending at 290 °C of a series of mixtures of poly(ethylene terephthalate) (PET) and poly(1,4-butylene succinate) (PBS) led to the formation of block PET/PBS copolyesters. The block lengths of the resulting copolymers decreased with the severity of the treatment. Copolyesters with PET/PBS molar compositions of 90/10, 80/20, 70/30, and 50/50 were prepared by this method and their composition and microstructure were characterized by ¹H and ¹³C NMR, respectively. The T_g, T_m, and crystallinity of the copolymers decreased as the content in PBS and the degree of randomness increased. The elastic modulus and tensile strength of the copolymers decreased with the content of PBS, whereas, on the contrary, the elongation at break increased. The PET/PBS copolymers exhibited a pronounced hydrolytic degradability, which increased with the content in 1,4-butylene succinic units. Hydrolysis mainly occurred on the aliphatic ester groups.     

醋酸羟丙基甲基纤维素琥珀酸酯溶液的高压静电场纺丝

研究了醋酸羟丙基甲基纤维素琥珀酸酯(HPMCAS)溶液高压静电场纺丝过程中高聚物分子量、溶液浓度、静电场强度对成纤性和纤维直径的影响,制备出直径范围为0.43μm～1.0μm的纤维。当溶剂、溶液浓度及静电场强度一定时,重均分子量-Mw分别为2.6万、4.8万和7.2万,HPMCAS溶液中只有7.2万者能纺丝得到光滑纤维。在静电场强度、溶剂组成一定条件下,HPMCAS可纺丝浓度范围为8%～15%(质量分数,下同),且随着纺丝溶液浓度的增大,所得纤维的平均直径逐渐增大。当其它条件保持一定时,随着纺丝电压的增大,所得纤维的平均直径呈下降的趋势,所得纤维结晶度略微增大。     

PBS/氧化石墨烯复合薄膜的制备与性能

目的利用氧化石墨烯(GO)为填料制备聚丁二酸丁二醇酯(PBS)的增强复合薄膜材料。方法以生物可降解材料PBS为基体,以GO为纳米增强相,首先用双十二烷基二甲基溴化胺(DDAB)对GO进行修饰,进而通过溶液复合法制备PBS/GO复合薄膜,并对其力学性能、结晶熔融行为和热稳定性进行表征。结果力学性能测试表明,在GO质量分数为0.1%时,复合薄膜的拉伸强度和断裂伸长率较纯PBS分别提高了37%和25%,但是随着GO含量的继续增加,其拉伸强度和断裂伸长率都呈现出下降趋势;热行为分析表明,GO的加入使PBS的熔融温度和结晶温度均有所提高,结晶度有所下降,但GO对PBS的热稳定性并无明显影响。结论适量GO的加入有利于改善PBS生物降解材料的力学性能和结晶熔融行为。