SnO催化合成环烷酸乙二醇酯增塑剂的研究

介绍了用SnO非酸性催化剂催化合成环烷酸乙二醇酯增塑剂(NAEP)的方法。讨论了反应温度、醇酸摩尔比、催化剂用量和反应时间等因素对酯化反应的影响,给出了适宜的工艺条件。 NAEP应用于PVC电缆料及丁腈橡胶配方中取得了良好的效果。与邻苯二甲酸酯增塑剂相比,具有更好的经济价值。     

固体超强酸在增塑剂合成中的应用

增塑剂在塑料的各种助剂中占有重要地位,采用固体超强酸代替浓硫酸催化合成增塑剂克服了传统方法中采用浓硫酸的许多缺点,将有很大的前景,本文对目前已经采用固体超强酸催化合成增塑剂的应用进行了总结.     

高分子量聚氯乙烯树脂增塑,填充体系的物理力学性能研究

本文研究聚合度及增塑剂、填充剂用量对高分子量聚氯乙烯（ＨＭＷＰＶＣ）树脂物理力学性能的影响规律，并将国内外ＨＭＷＰＶＣ树脂以及ＨＭＷＰＶＣ与通用型ＰＶＣ树脂进行了性能对比。结果表明，ＨＭＷＰＶＣ增塑、填充体系的拉什强度、撕裂强度冲击回弹性及压缩永久形变等物理力学性能均随聚合度的提高而有所增加，而且各项性能均优于通用型ＰＶＣ树脂，可有效地用作橡胶代用品。分子量相同的国内外ＨＭＷＰＶＣ树脂物理力学性能基本相同。但是，后者随着增塑剂用量的增加，弹性比前者有所提高；随着填充剂用量的增加，性能变化比前者缓慢．增加填充剂用量以降低制品的体积成本。笔者还时两者物理力学性能的差异与颗粒形态之间的关系进行了探讨。     

Plane stress fracture toughness of physically aged plasticized PETG as assessed by the essential work of fracture (EWF) method

The plane stress fracture toughness of amorphous copolyester (PETG) sheets plasticized by various amount of neopentylglycol dibenzoate (NPGDB in 0, 5, 10 and 20 wt%) was studied in as-received (AR) and rejuvenated (RJ) states by adopting the essential work of fracture (EWF) method. EWF tests were performed on deeply double-edge notched tensile loaded (DDEN-T) specimens at various deformation rates (2,10 and 100 mm/min) at room temperature. It was established that physical aging strongly affected the EWF terms. The specific yielding-related EWF increased with increasing deformation rate and decreased with increasing plasticizer content. The specific non-essential work and its necking-related constituent, which changed parallel to each other, remained constant up to 10 wt% NPGDB content and decreased afterwards. The plastic zone in the DDEN-T specimens was formed by cold drawing which is governed by the entanglement structure. This was demonstrated by the shape recovery of the plastic zone in the broken DDEN-T specimens after heating them above the T_g of the related PETG compound.     

Li NMR, ionic conductivity and self-diffusion coefficients of lithium ion and solvent of plasticized organic-inorganic hybrid electrolyte based on PPG-PEG-PPG diamine and alkoxysilanes

Organic-inorganic hybrid electrolytes based on poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) (D2000) complexed with LiClO₄ via the co-condensation of an epoxy trialkoxysilane and tetraethoxysilane have been prepared and plasticized by a solution of ethylene carbonate (EC)/propylene carbonate (PC) mixture (1:1 by weight). The cross-linked hybrid network shows no solvent exudation and retains a large amount of plasticizer over 70 wt.% in stable state. The in situ built in silica network provides the hybrid electrolytes with good mechanical properties. The ionic conductivity of the dry hybrid electrolyte films was enhanced by two orders of magnitude via plasticization, reaching a maximum conductivity value of 4.0 × 10⁻³ S/cm at 30 °C. Variable temperature ⁷Li-{¹H} magic angle spinning (MAS) NMR demonstrated that the Li⁺ cations can be complexed by the polymer network as well as by the plasticizing solvents, but not with the incorporated silica network. Furthermore, the ⁷Li chemical shift change indicated a progressive change in the lithium coordination from lithium-polymer to lithium-solvent with increasing temperatures. The role of the solvents and the mobility of the lithium ions were investigated by pulsed gradient spin echo (PGSE) NMR measurements to elucidate the behavior of the ionic conductivity.     

柠檬酸三丁酯、乙酰柠檬酸三丁酯合成工艺的研究

以柠檬酸、正丁醇为原料，采用直接酯化法合成了柠檬酸三丁酯。以柠檬酸三丁酯、乙酐和正丁醇为原料，采用共乙酰化-酯化法合成出乙酰柠檬酸三丁酯，并联产乙酸正丁酯。考察了催化剂用量、原料配比、反应温度、反应时间等因素对反应过程的影响，确定了较佳的操作条件，柠檬酸三丁酯收率≥98％，乙酰柠檬酸三丁酯收率≥98％。采用活性炭脱色技术对产品进行精制，明显改善了产品的色泽。     

Modification of poly(ethylene oxide) electrolyte by Brönsted base terminated oligo(ethylene glycol) and its application in dye-sensitized solar cells

Oligo(ethylene glycol) terminated by pyridine derivatives was designed and synthesized for improving the performance of the dye-sensitized solar cells (DSCs) with poly(ethylene oxide) based electrolyte. Effects of the plasticizer on retarding the recombination reaction in DSCs were characterized by current density–voltage characteristics. Combined with the results on electron density measurements, photovoltage–intensity characteristics correlate the retarded electron recombination with the upward movement of the conduction band edge and the reduced order of recombination reaction. The increased electron lifetimes of the DSCs with plasticizer modified electrolyte were confirmed by a small perturbation voltage decay technique. Additionally, WAXS measurements show that the presence of the plasticizer decreases the crystallinity of PEO electrolyte, which facilitates the mass transport of the redox species as impedance spectra indicated. By introducing guanidinium thiocyanate into the plasticizer modified PEO electrolyte, the performance of the DSCs is further improved, which yields the highest efficiency of 3.5%.     

碳酸钙高填充聚乙烯醇复合材料热塑加工性能研究

采用分子复合和增塑,以水、多元醇和含酰胺基团化合物组成复配增塑剂,通过热塑加工制备了碳酸钙(CaCO3)高填充聚乙烯醇(PVA)复合材料,采用差示扫描量热仪(DSC)、热重分析(TG)、高压毛细管流变仪等研究了复合材料的热性能、流变性能,探讨了复合材料中增塑剂的迁移率及其对制品尺寸稳定性的影响。结果表明,通过分子复合和增塑后,改性PVA及PVA/CaCO3复合材料获得较宽热塑加工窗口,当CaCO3含量为70%时热塑加工窗口达85.5℃;PVA/CaCO3复合材料的熔体为假塑性流体,其黏度满足传统挤出或注塑加工的黏度需要;随环境湿度增加,复合材料中增塑剂迁移率增加,CaCO3可抑制复合材料中增塑剂的迁移,一定程度上提高了复合材料的尺寸稳定性。     

利用生物基腰果酚分子改性制备新型环氧化增塑剂合成研究

以生物基腰果酚(cardanol)原料,对甲苯磺酸为催化剂,与乙酸酐进行酯化反应得到腰果酚乙酸酯(CA);然后,以甲酸为催化剂,双氧水为氧源合成环氧腰果酚乙酸酯(ECA)。考查了双氧水的浓度、甲酸和双氧水用量、反应温度、反应时间等对产品环氧值的影响。确定了最佳工艺条件：n (甲酸) : n (H2O2) : n (CA中双键)=0.2 : 1.5 : 1、反应温度为65 oC、反应时间为6 h。在最优条件下得到的产品为黄色透明油状液体,其环氧值可达到6.8 %。傅里叶红外 (FT-IR) 对CA及ECA进行结构表征,测定了ECA的酸值、加热减量、黏度、热重曲线等。结果表明,ECA符合环保增塑剂的产品性能要求。     

The effect of ethyl-lactate and ethyl-acetate plasticizers on PCL and PCL–HA composites foamed with supercritical CO2

The present study reports foaming of polycaprolactone (PCL) and PCL nano- and micro-composites with dispersed hydroxyapatite (HA) particles by means of binary mixtures of supercritical CO₂ (scCO₂) and either ethyl lactate (EL) or ethyl acetate (EA) as plasticizer. The effect of the size and concentration of HA particles, as well as the effects of the plasticizer type and the incorporation route were investigated aiming to fabricate porous scaffolds with uniform morphology and controlled pore size distribution. For this purpose, foaming experiments were carried out by selecting two operating temperatures, 40 and 45 °C, and two soaking times, 1 and 17 h. Furthermore, a double step of depressurization was used to promote the development of a double-scale pore size structure in porous scaffolds useful for tissue engineering.The results of this study indicated that supercritical foaming of PCL and PCL–HA composites is enhanced when the selected operating temperature and time are 45 °C and 17 h, respectively. Furthermore, although both EL and EA plasticizers enhanced the low temperature foaming of the materials, we demonstrated that the route of incorporation of the plasticizer is a critical aspect for enhancing composite foaming and scaffold fabrication. From this point of view, the best results were achieved when EA was pre-mixed with the polymeric powder for preparing a dough for the foaming process.