新型生物工程橡胶的设计和制备

以1,3-丙二醇、1,4-丁二醇、癸二酸和衣康酸4种单体为原料,采用熔融缩聚的方法合成新型生物工程橡胶聚(丁二醇/丙二醇/癸二酸/衣康酸)(PBPSI)共聚酯,并采用傅立叶转换红外光谱、凝胶渗透色谱、差示扫描量热仪等对其结构和性能进行表征。结果表明,PBPSI具有较高的相对分子质量、远低于室温的玻璃化温度、优异的物理性能和良好的环境稳定性。     

原位插层聚合法制备共聚酯/蒙脱土纳米复合材料

采用原位插层聚合法,制备了蒙脱土含量较高的共聚酯/蒙脱土纳米复合材料,意在做母料使用,含有该母料的聚合物复合材料的染色性能、吸湿浸润性能、抗静电性能及抗紫外性能等都有所改善。阐述了合适的共聚酯/蒙脱土纳米复合材料的制备工艺,讨论了制备过程中的影响因素,结果发现:在采用酯交换-缩聚反应釜进行原位插层聚合制备共聚酯/蒙脱土纳米复合材料的过程中,蒙脱土在缩聚釜中加入更符合生产实际;缩聚反应的实际过程证明了蒙脱土中含有的金属离子对缩聚反应有催化作用;另外,控制聚合的最终温度不超过278℃。最后,对共聚酯/蒙脱土纳米复合材料的结构进行了表征。     

低熔点快固化聚酯热熔胶的合成与性能研究

在对苯二甲酸二甲酯(DMT)和1,4-丁二醇(BD)合成聚酯体系中引入其它共聚组分,制备了快速结晶的低熔点共聚酯热熔胶,其熔点约为70～120℃。由于熔点越低结晶性能越差,因此在合成聚酯热熔胶的基础上,进一步对其进行改性,且对组成与性能的关系进行了研究。结果表明,聚酯热熔胶的熔点和结晶性能随DMT含量的增加而升高;二元醇体系的配比和含量对熔点和结晶性能有很大影响,当混合二元醇物质的量比为1时具有最低的熔点,BD/HD(1,6-己二醇)体系比EG(乙二醇)/HD体系的结晶速率快,BD/HD体系中结晶速率随HD含量的增加而加快。     

含磷阻燃共聚酯的热降解动力学及耐热性能研究

采用不同的升温速率,用Kissinger法研究了聚对苯二甲酸乙二酯(PET)和侧基含磷共聚酯(FR-PET)在氮气气氛中的热降解动力学;采用时-温等效原理对其耐热性能进行了深入研究,确定了动力学参数与材料寿命方程之间的关系,为直接估算材料的使用寿命提供了捷径。结果表明,阻燃剂的引入降低了PET整个热降解过程的平均活化能、指前因子及反应级数,并使PET的不同失重率所对应的时间延长,即FR-PET的耐热性能有所提高;在同一温度下,360℃以前FR-PET失重一半的时间要短于纯PET,在360℃以后则长于纯PET,说明在高温下相对于纯PET要难于点燃。利用Kissinger法确定的寿命与动力学关系式可较准确地预测材料的寿命。     

纺织浆料用共聚酯的合成

经大量试验,合成出能够溶解于水的,具有差异化性能的聚酯。通过上浆试验、溶液黏度及黏度稳定性测定以及差热分析DSC等分析后,得到该产品完全满足纺织浆料的一般要求。在生产过程中,添加一定量的阻垢剂后,可使溶液中的不溶物大幅度的减少。     

丙三醇对PBST共聚酯结构和性能的影响

基于生物可降解性聚酯——聚丁二酸-共-对苯二甲酸丁二醇酯(PBST),通过原位添加不同含量的丙三醇作为第四单体,制备出共聚改性的PBST共聚酯。通过核磁共振仪(NMR)、差示扫描量热仪(DSC)、广角X射线衍射仪(WAXD)及接触角测试,分别对PBST共聚酯的结构和性能进行了研究。结果表明:丙三醇的加入并没有改变PBST共聚酯的化学组成和结构;随着丙三醇含量的增加,共聚酯的玻璃化转变温度先上升后下降,而熔点是逐步降低的;改性前后和拉伸前后PBST的晶型均未发生变化,但分子结构的规整性受到破坏,且发生拉伸诱导取向;改性PBST共聚酯的亲水性能较纯PBST有明显提高。     

High Compatibility and Improved Barrier Performance in Blends Based on a Copolyester Modified with a Poly(amino ether) Resin

Summary: The structure and properties of blends of a PCTG and a PAE resin obtained by direct injection molding have been studied. The blends were almost immiscible, and were composed of a nearly pure PAE phase and a mixed PCTG‐rich phase containing minor PAE amounts. Electron microscopy observations showed a high intermixing level between both components. The permeability data indicated an improved barrier protection of PCTG upon PAE addition. The Young's modulus and the yield stress of the blends followed a linear behavior with respect to composition, while values close or slightly below linearity were observed for the break properties. The combined effects of the small dispersed particle size and the proposed good interfacial adhesion are stated as the main factors responsible for the positive mechanical behavior. The impact strength showed an unexpected variability for PCTG‐rich blends, which is attributed to a ductile‐brittle transition of PCTG.

Ductility of PCTG/PAE blends vs. composition.     

PET-PEN共聚酯对PET/PEN共混物的增容作用及其机理

使用聚对苯二甲酸乙二酯(PET)-聚萘二甲酸乙二酯(PEN)无规共聚酯作增容剂,通过双螺杆挤出机熔融共混,制备了不同PET-PEN共聚酯用量的PET/PEN共混物,采用差示扫描量热分析、热重分析、热变形温度测试以及力学实验等方法,研究了该共混物的相容性及其它性能。结果表明,PET-PEN共聚酯对PET/PEN共混物具有明显的增容作用,能有效提高PET/PEN共混物的热稳定性,其用量越高,热稳定性提高越明显,当PET-PEN共聚酯用量为15质量份时,起始失重温度提高了20.3℃。PET-PEN共聚酯增容剂能提高PET/PEN共混物的维卡软化温度、拉伸和弯曲性能以及冲击性能,当PET-PEN共聚酯用量为5质量份时,增容改性的综合效果最好。     

Synthesis of full bio-based,fast degradable,and high strength copolyesters: Poly(butylene succinate-sebacicate-salicylicate-malicate)

The presence of petroleum-based monomers in the backbone of poly(butylene succinate-co-adipate) (PBSA) restricts its application in light of increasingly stringent environmental regulations. In this study, a novel full bio-based biodegradable random copolymer poly(butylene succinate-sebacicate-salicylicate-malicate) (PBSSeSa-c-M) was designed and synthesized. The comprehensive study encompassed the structural alterations, properties, and degradation resulting from the inclusion of salicylicate sebacicate and malicate units. The incorporation of salicylic acid effectively enhanced the tensile modulus of the copolymer, due to the effect of rigid benzene ring. Meanwhile, the addition of sebacic acid regulated the degradation rate. The introduction of malic acid significantly improved the rheological properties, endowing the copolymer with exceptional processability. The obtained high molecular weight PBSSeSa-c-M exhibited outstanding film-blowing processability with an intrinsic viscosity of 1.58 dL/g and melt flow rate of 7.34 g/10 min. The tensile modulus reaches 235.43 MPa that is comparable to commercial PBSA. Besides, the degradation of PBSSeSa-c-M reaches 18.92% over 4 weeks, far higher than that of PBSA. In conclusion, this work provides a design and synthesis for a new kind of biodegradable copolyester that satisfies the requirement of rapid degradation in single-use plastics.     

Novel Copolyesters Based on s-Triazine Derivatives

Ten copolyesters have been synthesized by polycondensation of MPNCCT and different mixtures of diols, such as: BPA + BPC, BPA + BPS, BPA + 1,4-DHA, BPA + Ph, BPA + C, BPA + R, BPA + EG, BPC + Ph, BPC + R, and Ph + 1,4-DHA. All the copolyesters have been characterized by IR spectra, NMR spectra, solubility, density and viscosity measurements and thermogravimetric analysis, TGA.