聚(对苯二甲酸乙二醇酯-co-对苯二甲酸异山梨醇酯)预结晶及固相聚合研究

研究了不同异山梨醇(ISB)含量的聚(对苯二甲酸乙二醇酯-co-对苯二甲酸异山梨醇酯)(PEIT)共聚酯预结晶及固相聚合工艺。探讨了温度、时间与PEIT共聚酯预结晶温度、固相聚合反应速率之间的关系;利用差式扫描量热仪(DSC)分析研究PEIT共聚固相聚合前后的热性能变化情况。结果表明:随着ISB用量的增加,PEIT共聚酯结晶困难,预结晶时间增加,固相聚合反应速率减慢;随着温度升高,PEIT共聚酯固相聚合反应速率加快,但仍慢于聚对苯二甲酸乙二醇酯(PET);固相增粘后PEIT共聚酯玻璃化转变温度(Tg)与ISB含量呈线性上升关系。     

聚对苯二甲酸乙二醇酯／蒙脱土复合物的制备与表征

分别采用蒙脱土与对苯二甲酸乙二醇酯(BHET)和与乙二醇(EG)混合的方法，通过原位插层聚合制备聚对苯二甲酸乙二醇酯／蒙脱土(PET／MMT)复合材料，研究了MMT含量对PET粘均相对分子质量、复合材料微观结构及热和结晶性能的影响。结果表明，随有机化MMT的加入量增加，PET的粘均相对分子质量降低；将有机化MMT分散在乙二醇中再聚合所得复合物中MMT分散更为均匀；MMT的加入使PET的玻璃化温度、冷结晶温度和维卡软化温度降低，BHET法的PET结晶度和热结晶温度增加，而EG法的PET结晶度和热结晶温度下降。     

聚酯类共混改性聚对苯二甲酸丁二醇酯

讨论了聚碳酸酯(PC)、聚对苯二甲酸乙二醇酯(PET)以及聚苯二甲酸三甲酯(PTT)共混改性聚对苯二甲酸丁二醇酯(PBT)的研究进展。聚酯之间具有较好的相容性。通过添加其它聚酯弥补了PBT的一些缺点，从而拓宽了PBT的应用领域。     

纤维用PET/CGP的共混改性研究

采用聚对苯二甲酸乙二醇酯(PET)与聚对苯二甲酸乙二醇酯聚对苯二甲酸丁二醇酯聚丁二醇共聚酯(CGP)以不同比例共混制得一系列的改性聚酯,研究了共混改性聚酯切片的热性能和流变性能。结果表明,随着CGP加入量的增加,PET/CGP共混体系的玻璃化转变温度Tg,冷结晶峰温度Tc和熔点Tm均有所下降,热稳定性比普通PET低;PET/CGP熔体呈现“切力变稀”现象,其表观黏度明显下降。     

聚对苯二甲酸乙二醇酯合成基本原理Ⅱ.聚对苯二甲酸乙二醇酯的合成

概述了聚对苯二甲酸乙二醇酯(PET)合成的基本原理，以及由对苯二甲酸乙二醇酯(BHET)单体经缩聚反应合成PET的反应机理、合成过程中的主要化学反应，详述了BHET缩聚合成PET的主要影响因素。由BHET缩聚合成PET属于逐步缩合聚合过程，缩聚过程中存在多个化学反应，包括链增长反应、链降解反应及网状结构凝胶物生成的副反应。BHET缩聚合成PET的影响因素主要有催化剂种类及其用量、稳定剂种类及其用量、反应温度、反应釜余压及物料的液层厚度等。今后，在PET及其共聚酯的合成中，应加大无毒催化剂的使用与推广、非石油基原料的开发及化学改性共聚酯的开发，以及废旧聚酯的化学法回收再生利用。     

快速结晶聚对苯二甲酸乙二醇酯复合物

本发明提供了一种快速结晶聚对苯二甲酸乙二醇酯复合物及其制备方法。该复合物由30—80份(重量份数，下同)聚对苯二甲酸乙二醇酯、012—8份复合结晶成核剂、10—25份复合阻燃剂、10—60份填充增强剂、0．1—5份其它加工助剂经熔融挤出而成。本发明采用快速结晶技术，解决了聚对苯二甲酸乙二醇酯作为工程塑料使用时成型加工过程中结晶速率慢、注模温度高、模塑周期长的缺点，可广泛用于制造电子电器、机器机械、家电等的零部件。     

聚对苯二甲酸乙二醇异山梨醇酯的结构和性能

以异山梨醇、乙二醇、对苯二甲酸(PTA)为原料,采用PTA法制备了异山梨醇质量分数为20%的对苯二甲酸/乙二醇/异山梨醇的无规共聚酯(PESIT)。PESIT的氢核磁共振谱和红外光谱分析表明,异山梨醇参与了对苯二甲酸与乙二醇的聚合反应。差热和热失重分析表明:PESIT具有较好的热稳定性,玻璃化转变温度和热分解温度较聚对苯二甲酸乙二酯(PET)高。纺丝速度3150 m/min的POY纺丝实验表明:PESIT与PET一样具有好的可纺性,制得的POY断裂强度为1.72 cN/dtex,断裂伸长为175%。     

聚对苯二甲酸乙二醇酯特性的研究进展(英文)

简述了近年来聚对苯二甲酸乙二醇酯，关于热降解、扩链、结晶完整性、双冷结晶峰，以及溶剂诱导结晶等方面的研究进展     

聚对苯二甲酸乙二醇酯合成的研究进展

综述了合成聚对苯二甲酸乙二醇酯的4种方法以及相关的机理,其中详细地阐述了聚酯缩聚过程中所用的催化剂的研究进展,并展望了聚对苯二甲酸乙二醇酯合成技术的发展前景,指明了其发展方向.     

PTMG-b-PET共聚酯的合成及性能

以对苯二甲酸、乙二醇以及聚四氢呋喃(PTMG)为原料,采用熔融缩聚法合成了不同PTMG比例的聚对苯二甲酸乙二醇酯-聚四氢呋喃(PET-PTMG)聚醚酯,研究了PTMG含量对共聚酯缩聚反应过程的影响。利用红外光谱法、核磁共振波谱法分析了共聚酯结构、序列分布,利用差示扫描量热分析(DSC)、热失重分析研究了共聚酯热性能、结晶动力学以及热稳定性。研究表明,投入体系的聚醚基本都进入了聚合物分子链;PTMG含量增加,聚合反应动力黏度增长变缓,共聚酯玻璃化转变温度(T_g)、结晶温度(T_c)、熔点(T_m)均明显降低,熔融结晶温度(T_mc)先上升后下降,试验制备的共聚酯较常规PET结晶速率更快。在氮气氛围中,共聚酯的热降解为一阶反应,PTMG含量增加,共聚酯热稳定性明显降低。     

Synthesis of novel biodegradable poly(butylene succinate) copolyesters composing of isosorbide and poly(ethylene glycol)

A series of biodegradable isosorbide‐based copolyesters poly(butylene succinate‐co‐isosorbide succinate‐co‐polyethyleneoxide succinate) (PB_xI_yE_zS) were synthesized via bulk polycondensation in the presence of dimethyl succinate (DMS), 1,4‐butanediol (BDO), poly(ethylene glycol) (PEG) and isosorbide (ISO). The crystallization behaviors, crystal structure and spherulite morphology of the copolyesters were analyzed by differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXD) and polarizing optical microscopy (POM), respectively. The results indicate that the crystallization behavior of the copolyesters was influenced by the content of isosorbide succinate (IS) and polyethyleneoxide succinate (PEOS) units, which further tuned the mechanical and biodegradable properties of the copolyesters. The PB_xI_yE_zS copolyesters, compared to pure poly(butylene succinate), showed lower crystallization temperature, melting temperature, degree of crystallinity and degradation rate while a significant increase in glass transition temperature with increasing isosorbide content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Poly(ethylene terephthalate‐co‐isophthalate) copolyesters obtained from ethylene terephthalate and isophthalate oligomers

A series of poly(ethylene terephthalate‐co‐isophthalate) copolyesters containing upto 50%‐mole of isophthalic units were prepared by polycondensation from ethylene terephthalate and ethylene isophthalate fractions of linear oligomers containing from 5 to 6 repeating units in average. The polyesters were obtained in good yields and with high‐molecular‐weights. The microstructure of the copolyesters was studied as a function of reaction time by ¹³C‐NMR showing that a random distribution of the comonomers was achieved since the earlier stages of polycondensation. The melting temperature and enthalpy of the copolyesters decreased with the content of isophthalic units so that copolyesters containing more than 25% of these units were amorphous. Isothermal crystallization studies made on crystalline copolyesters revealed that the crystallization rate of copolyesters decreased with the content in isophthalic units. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Nonisothermal crystallization behavior of poly (butylene terephthalate)–poly (ethylene terephthalate‐co‐isophthalate‐co‐sebacate) segmented copolyesters

In this paper, two different analytical methods were applied to investigate nonisothermal crystallization behavior of copolyesters prepared by melting transesterification processing from bulk polyesters involving poly (butylene terephthalate) (PBT) and ternary amorphous random copolyester poly(ethylene terephthalate‐co‐isophthalate‐co‐sebacate) (PETIS). The results show that the half‐time of crystallization of copolyesters depended on the reaction time and decreased with the content of ternary polyesters in the amorphous segment. The modified Avrami model describes the nonisothermal crystallization kinetics very well. The values of the Avrami exponent range from 2.2503 to 3.7632, and the crystallization kinetics constant ranges from 0.0690 to 0.9358, presenting a mechanism of three‐dimensional spherulitic growth with heterogeneous nucleation. Ozawa analysis, however, failed to describe the nonisothermal crystallization behavior of copolyesters, especially at higher cooling rate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1232–1238, 2003     

Implementing plant‐derived isosorbide and isomannide as comonomers for polyester synthesis: Effects of crystallization properties on optical properties

This article describes the implementation of plant‐derived isosorbide (IS) and isomannide (IM) in the copolymerization modification of poly(ethylene terephthalate). The effects of the two comonomers on the optical, crystallization, and thermal properties of the resulting copolyesters were studied using the following analytical methods: proton nuclear magnetic resonance; differential scanning calorimetry; X‐ray diffraction; thermogravimetry; and ultraviolet‐visible spectroscopy. As comonomers, IS and IM increased the transmittance and reduced the haze of the copolyesters. Moreover, while IM improved the optical properties more than did IS, both monomers improved the optical properties of the copolyesters by lowering its crystallization ability. After the copolymerization modification, the crystallization rate of the copolyesters was reduced, decreasing the crystallinity and crystal size and thereby reducing the light transmission interference. The comonomers also altered the light absorption properties of the copolyesters and conferred a substantial increase in the transmittance of near‐infrared (NIR) wavelengths. These changes in optical properties exhibit the potential of these comonomers for applications in optical materials and NIR detectors. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45444.     

Characterization of the mechanical properties,crystallization, and enzymatic degradation behavior of poly(butylene succinate‐co‐ethyleneoxide‐co‐DL‐lactide) copolyesters

A series of aliphatic biodegradable poly (butylene succinate‐co‐ethyleneoxide‐co‐DL ‐lactide) copolyesters were synthesized by the polycondensation in the presence of dimethyl succinate, 1,4‐butanediol, poly(ethylene glycol), and DL ‐oligo(lactic acid) (OLA). The composition, as well as the sequential structure of the copolyesters, was carefully investigated by ¹H‐NMR. The crystallization behaviors, crystal structure, and spherulite morphology of the copolyesters were analyzed by differential scanning calorimetry, wide angle X‐ray diffraction, and polarizing optical microscopy, respectively. The results indicate that the sequence length of butylene succinate (BS) decreased as the OLA feed molar ratio increasing. The crystallization behavior of the copolyesters was influenced by the composition and sequence length of BS, which further tuned the mechanical properties of the copolyesters. The copolyesters formed the crystal structures and spherulites similar to those of PBS. The incorporation of more content of ethylene oxide (EO) units into the copolyesters led to the enhanced hydrophilicity. The more content of lactide units in the copolyesters facilitated the degradation in the presence of enzymes. The morphology of the copolyester films after degradation was also studied by the scanning electron microscopy. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

三元共聚酯的固相聚合及其产品的性能表征

研究了间苯二甲酸（IPA）质量数分别为1．5％和3．0％的对苯二甲酸－间苯二甲酸－乙二醇共聚酯的固相聚合。探讨了反应温度、IPA质量分数与固相增粘速率之间的关系；利用DSC、TG分析研究了IPA质量分数和固相聚合条件对样品结晶性能及共聚酯热稳定性能的影响。结果表明：随着IPA质量分数的增大，共聚酯的熔点下降，热稳定性能降低，而增粘速率在一定范围内有所增加。     

Nonisothermal crystallization behavior of biodegradable poly(butylene terephthalate‐co‐butylene adipate‐co‐ethylene terephthalate‐co‐ethylene adipate) copolyester

A series of biodegradable aliphatic‐aromatic copolyester, poly(butylene terephthalate‐co‐butylene adipate‐co‐ethylene terephthalate‐co‐ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic acid (AA), 1,4‐butanediol (BG) and ethylene glycol (EG) by direct esterification and polycondensation. The nonisothermal crystallization behavior of PBATE copolyesters was studied by the means of differential scanning calorimeter, and the nonisothermal crystallization kinetics were analyzed via the Avrami equation modified by Jeziorny, Ozawa analysis and Z.S. Mo method, respectively. The results show that the crystallization peak temperature of PBATE copolyesters shifted to lower temperature at higher cooling rate. The modified Avrami equation could describe the primary stage of nonisothermal crystallization of PBATE copolyesters. The value of the crystallization half‐time (t_1/2) and the crystallization parameter (Z_c) indicates that the crystallization rate of PBATE copolyesters with more PTA content was higher than that with less PTA at a given cooling rate. Ozawa analysis was not suitable to study the nonisothermal crystallization process of PBATE copolyesters, but Z.S. Mo method was successful in treatingthis process. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Fast crystallization of liquid crystalline copolyesters based on poly(ethylene terephthalate)

Crystallization of a series of liquid crystalline copolyesters prepared from p‐hydroxybenzoic acid (HBA), hydroquinone (HQ), terephthalic acid (TA), and poly(ethylene terephthalate) (PET) was investigated by using differential scanning calorimetry (DSC). It was found that these copolyesters are more crystalline than copolyesters prepared from PET and HBA. Insertion of HQ–TA disrupts longer rigid‐rod sequences formed by HBA and thus enhances molecular motion and increases the crystallization rate. The effects of additives on the crystallization of the copolyesters were also studied. Sodium benzoate (SB) and sodium acetate (SA) increase the crystallization rate of the copolyesters at low temperature, but not at high temperature. It is most likely that liquid crystalline copolyesters do not need nucleating agents, and small aggregates of local‐oriented rodlike segments in nematic phase could act as primary nuclei. Chain scission of the copolyesters caused by the reaction with the nucleating agents was proved by the determination of intrinsic viscosity and by the IR spectra. Diphenylketone (DPK) was shown to effectively promote molecular motion of chains, leading to an increase in the crystallization rate at low temperature, but it decreased the crystallization rate at high temperature. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 497–503, 2001     

Biodegradable poly(ethylene succinate) blends and copolymers containing minor amounts of poly(butylene succinate)

Poly(ethylene succinate) (PES), poly(butylene succinate) (PBS), and PES‐rich copolyesters were synthesized using an effective catalyst, titanium tetraisopropoxide. PES was blended with minor amounts of PBS for the comparison. The compositions of the copolyesters and the blends were determined from NMR spectra. Their thermal properties were studied using a differential scanning calorimeter (DSC), a temperature modulated DSC (TMDSC), and a thermogravimetric analyzer. No significant difference exists among the thermal stabilities of these polyesters and blends. For the blends, the reversible curves of TMDSC showed a distinct glass‐rubber transition temperature (T_g), however, the variation of the T_g values with the blend compositions was small. Isothermal crystallization kinetics and the melting behavior after crystallization were examined using DSC. Wide‐angle X‐ray diffractograms (WAXD) were obtained for the isothermally crystallized specimens. The results of DSC and WAXD indicate that the blends have a higher degree of crystallinity and a higher melting temperature than those of the corresponding copolymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

The crystallization rate of poly(ethylene terephthalate) accelerated by co[poly(butylene terephthalate‐p‐oxybenzoate)] copolyesters

Poly(ethylene terephthalate) (PET) was blended with three different kinds of co[poly(butylene terephthalate‐p‐oxybenzoate)] copolyesters, designated B28, B46, and B64, with the level of copolyester varying from 1 to 15 wt %. All samples were prepared by solution blending in a 60/40 by weight phenol/tetrachloroethane solvent at 50°C. The crystallization behavior of samples was then studied via differential scanning calorimetry. The results indicate that these three copolyesters accelerate the crystallization rate of PET in a manner similar to that of a nucleating agent. The acceleration of PET crystallization rate was most pronounced in the PET/B28 blends with a maximum level at 10 wt % of B28. The melting temperatures for the blends are comparable with that of pure PET. The observed changes in crystallization behavior are explained by the effect of the physical state of the copolyester during PET crystallization as well as the amount of copolyester in the blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 587–593, 2000