以涤纶废丝、废块制备对苯二甲酸二(2-乙基)己酯的研究

探讨了涤纶(PET)生产中的废丝、废块与2 乙基己醇(2 EH)直接醇解合成对苯二甲酸二(2 乙基)己酯(DOTP)的工艺过程及条件。当n(2 EH)∶n(PET)=(2 8～3 0)∶1,反应温度210～230℃,催化剂用量占总投料量的质量分数为0 2%～0 3%时,可以得到二级品标准的DOTP,对PET的收率为97 5%～97 9%。     

用废涤纶丝合成对苯二甲酸二（2－乙基己）酯及应用

本文介绍了以废涤纶丝为主要原料，用酯交换法生产对苯二甲酸二（２－乙基已）酯（ＤＯＴＰ），使用了一种新催化剂，大大缩短反应时间，并介绍了ＤＯＴＰ的应用情况。     

加氢法生产环己烷1,2-二甲酸二(2-乙基己)酯工艺

以邻苯二甲酸二(2-乙基己)酯（DEHP,工业级）为原料,采用固定床加氢工艺和贵金属Ru-Pd催化剂,制备环己烷1,2-二甲酸二(2-乙基己)酯。分别考察了温度、压力、空速、氢气与原料的体积比对反应活性的影响。试验结果表明：在反应温度190℃、压力15MPa、体积空速0.5h?1、氢气与原料的体积比为800∶1的条件下,原料DEHP转化率保持在99.99%以上,目标产物选择性高于99.7%。连续运行1000h,催化剂仍具有优异的加氢活性。     

固体酸催化合成马来酸(2-乙基己)酯

用固体酸作催化剂制备了马 来酸(2-乙基己)酯 ,并用正 交实验确定了最佳工艺条件 ,此条件下目的产物收率为97.2%。固体酸作催化剂与产 品容易分离 ,后处理简单,有 利于环 保。     

用干氢催化树脂催化合成马来酸二(2-乙基己)酯

用干氢催化树脂作催化剂合成了马来酸二(乙-乙基己)酯,同时与硫酸、对甲苯磺酸的催化效果进行了比较。在干氢催化树脂作催化剂情况下,催化剂与产品容易分离,产品后处理简单,从而使生产工艺得以简化,节约能源、减少废水,优于传统的硫酸、对苯磺酸催化剂。     

2-氯乙基膦酸二-(2-氯乙基)酯的合成新方法

研究了标题化合物的合成新方法。以2-氯乙基膦酸二酰氯为原料,与环氧乙烷反应制备得到产物,其气相纯度98%,收率98%。利用1HNMR、13CNMR、31PNMR和HRMS表征确定产物结构,并探讨了反应原料配比、溶剂等对反应的影响,所合成的产物可在分析测试方法开发中直接作为标样使用。     

偏苯三酸三(2-乙基己)酯的合成与应用

介绍了偏苯三酸三(2-乙基己)酯的性能、生产新工艺、应用及发展前景.     

以涤纶废丝、废块制备对苯二甲酸二（2—乙基）己酯的研究

探讨了涤纶(PET)生产中的废丝、废块与2—乙基乙醇(2—EH)直接醇解合成对苯二甲酸二(2—乙基)己酯(DOTP)的工艺过程及条件。当n(2—EH)：n(PET)＝(2．8—3．0)：1，反应温度210—230℃，催化剂用量占总投料量的质量分数为0．2％一0．3％时，可以得到二级品标准的DOTP，对PET的收率为97．5％一97．9％。     

酯化法合成对苯二甲酸二(β-羟乙基酯)的研究

以对苯二甲酸和乙二醇为原料,采用自制催化剂合成出了对苯二甲酸二(β-羟乙基酯)(BHET).最佳反应条件:1 mol对苯二甲酸使用0.2 g催化剂,醇酸摩尔比为12∶1,反应时间为10h,反应温度为185℃.粗品经结晶、重结晶可得质量分数＞99％的BHET产品.     

引发剂过氧化二碳酸二(2-乙基己)酯的红外光谱定性分析

运用傅立叶红外光谱技术 ,将常规的红外谱图解析程序和对比定性方法相结合 ,分析了PVC聚合用的引发剂过氧化二碳酸二 (2 -乙基己 )酯 ,并与其标准样品谱图及原材料氯代甲酸 2 -乙基己酯进行了对比定性分析 ,确定了各基团取代情况 ,为判定实验进展情况提供了可靠信息。     

Aminolytic depolymerization of poly (ethylene terephthalate) bottle waste by conventional and microwave irradiation heating

Poly (ethylene terephthalate) (PET) is the most popular thermoplastic polymer. The ever-growing production and utilization of PET has led to postconsumer waste disposal problems because of its nonbiodegradability. The chemical depolymerization of PET waste is a possible remedy, as it results in some recyclable products. The aminolytic depolymerization of PET bottle waste with hydrazine monohydrate by conventional and nonconventional (with microwave irradiation) heating was carried out with simple chemicals as catalysts, such as sodium acetate and sodium sulfate. The yield of the product was optimized through variations in the time of aminolysis, the catalyst concentration, and the PET:hydrazine monohydrate ratio. The pure product obtained in good yield (86%) was analyzed by Fourier transform infrared spectroscopy, NMR, and differential scanning calorimetry and was identified as terephthalic dihydrazide. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Kinetics of neutral hydrolytic depolymerization of PET (polyethylene terephthalate) waste at higher temperature and autogenious pressures

Neutral hydrolytic depolymerization of PET (Polyethylene terephthalate) waste was studied using 0.5‐L high pressure autoclave at the temperatures 100, 150, 200, 230, and 250°C at autogenious pressures 15, 80, 230, and 451 psi (pound per square inch) and time intervals of 60, 90, 120, and 150 min, respectively. The obtained terephthalic acid (TPA) was characterized by measuring its acid value and recording FTIR spectra. Depolymerization of the PET by neutral hydrolysis was found to be first order with velocity constant in the order of 10^?2 min^?1. Energy of activation and frequency factor were obtained by slope and intercept of Arrhenius plot, which were found to be 99.58 KJ mole^?1 and 2.9 × 10⁸ min^?1respectively. Effect of temperature on rate of depolymerization reaction was also studied and optimized: rate of reaction increased drastically on increase in temperature from 150 to 200°C. Modified shrinking core model based on acid values focused the light on depolymerization of the PET into TPA by fragmentation due to formation of pores and cracks. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

有色废弃PET材料化学回收新工艺

为了解决有色废弃PET材料回收难的问题,促进资源循环利用,研究了有色PET以超临界甲醇技术进行解聚,并脱色提纯得到对苯二甲酸二甲酯的工艺流程。探讨了有色PET在超临界甲醇中的降解规律,并对脱色方案进行了筛选。探索了不同级别的PET材料解聚条件的差异。结果表明：纤维级材料在265 ℃,11 MPa下,超临界甲醇解聚30 min后,用溶解-热过滤-沉析的方法脱色提纯,对苯二甲酸二甲酯的产率可达到85%,纯度达到99.9%以上,白度达到87.5%;瓶片级材料呈现的解聚规律与纤维级变化趋势相同,但达到相同的解聚率,明显需要更长的反应时间。     

对苯二甲酸二辛酯生产技术及工艺改进

对TPA法生产对苯二甲酸二辛酯的酯化阶段的回流工艺进行了改进，并对提高DOTP的生产速度进行了讨论。     

Glycolysis of postconsumer polyethylene terephthalate waste

Glycolytic depolymerization of polyethylene terephthalate (PET) bottle waste was attempted using ethylene glycol (EG) in the presence of chlorides of zinc, lithium, didymium, magnesium, and iron as catalysts. Virtual monomer bis (2‐hydroxyethyl terephthalate) (BHET) was obtained in all cases with nearly 74% yield, the highest yield being achieved with zinc chloride catalyst 0.5% w/w, PET : EG ratio 1 : 14 and 8 h under reflux conditions. The results were comparable to other catalysts like common alkalis, acids, and salts of some earth metals and zeolites used earlier although parameters of glycolysis were observed to vary depending on the catalyst. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of urethane oils from waste poly(ethylene terephthalate) bottles

Waste poly(ethylene terephthalate) (PET) bottles were glycolyzed by propylene glycol (PG) at a weight ratio of PET to PG of 37.5 : 62.5 using zinc acetate as a catalyst. The glycolyzed product, consisting of oligomeric diols with a number‐average molecular weight range of 458–844, was obtained. It was further reacted with soybean oil and toluene diisocyanate to obtain urethane oils at hydroxyl to isocyanate ratios from 1 : 1 to 1 : 0.7, with and without methanol acting as a blocking agent. All the synthesized urethane oils were yellowish, transparent, low‐viscosity liquids of low molecular weights. A lower diisocyanate content and the presence of a blocking agent resulted in higher viscosity, higher molecular weight, and shorter drying time. The films of all synthesized urethane oils exhibited good hardness and adhesion. They also showed excellent water and acid resistance but only fair alkali resistance. However, these prepared urethane oils had lower flexibility and poorer wear resistance compared to those of the commercial urethane oil. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3040–3045, 2004     

Synthesis and characterization of waterborne polyurethane dispersion from glycolyzed products of waste polyethylene terephthalate used as soft and hard segment

Waste polyethylene terephthalate (PET) bottles were collected, cleaned and then depolymerized by glycolysis with neopentyl glycol (NPG) and dipropylene glycol (DPG), in the presence of N-butyl titanate catalyst. The product, named glycolyzed oligoesters, obtained through the depolymerization, were employed respectively in hard segment and soft segment in the synthesis of novel waterborne polyurethane dispersions (PUDs) via a simple and environmentally benign process. In addition, a polyurethane dispersion without glycolyzed oligoesters was synthesized as a comparison. The bulk structure of PET glycolyzed oligoesters and PUDs films were characterized by Fourier transform infrared spectroscopy (FT-IR), H-nuclear magnetic resonance (¹H NMR) and Gel permeation chromatography (GPC). The results illustrated that glycolyzed oligoesters were successfully introduced into the hard and soft segment of the polyurethanes. Furthermore, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to investigate the thermal properties of the PET glycolyzed oligoesters and PUDs films. The results showed that the thermal resistance of waterborne polyurethanes obtained with glycolyzed oligoesters increased due to lower degrees of phase separation. X-ray diffraction indicated that all synthesized polyurethanes exhibited reduced degrees of orientation. Due to the balance between hard-/soft-segment of the waterborne polyurethane dispersions, the formulations containing glycolyzed oligoesters within the hard segment sections of the polyurethanes provided the best performance.     

应用微波法对废PET进行醇解的研究

研究了一种应用微波技术在常压下对废PET催化降解以实现化学回收的方法。考察了在微波作用下,醇解温度、物料配比、催化剂含量及醇解剂官能度对废PET降解程度及降解产物的影响,并利用红外光谱仪对降解产物的化学结构进行了分析。结果表明:综合考虑废PET的醇解程度、醇解产物的性能以及经济成本因素,选定的最佳工艺条件是微波功率500W时,醇解时间15min、反应温度220℃、二甘醇与废PET的质量比为1.25、醋酸锌用量0.2%;其他反应条件不变,将醇解剂改为甘油和二甘醇的混合醇,混合醇与废PET的质量比为1.5,当二甘醇与甘油质量比为1:1时,醇解产物羟值最高,可以达到477mg/g;实验所得的废PET的二甘醇醇解产物是羟基封端分子链含有醚键的聚酯多元醇。     

玉米乙二醇合成PET的研究

以玉米为原材料生产的乙二醇合成PET并进行固相缩聚,对其生产过程及其结果进行分析和讨论。     

Investigation of alkaline hydrolysis of polyethylene terephthalate by differential scanning calorimetry and thermogravimetric analysis

The hydrolytic depolymerization of polyethylene terephthalate (PET) with alkaline hydroxides was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The reactions of the mixtures were conducted in their solid states under nitrogen atmosphere. The experimental results showed that potassium hydroxide possessed the hydrolytic activity of depolymerizing PET into small molecules such as ethylene glycol; in contrast, sodium hydroxide did not. The production rate of ethylene glycol was enhanced by increasing charge ratio of potassium hydroxide to PET. The presence of water facilitated the alkaline hydrolysis of PET; however, the presence of metal acetates decreased the hydrolysis rate. The activation energy for alkaline hydrolysis of PET determined by the thermograms was in good agreement with the value obtained from the experiments in a batch reactor. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1939–1945, 1998