废旧PET回收循环利用方法的研究进展

综述了废旧聚对苯二甲酸乙二醇酯(PET)的物理回收法、化学回收法、生物回收法和创新循环利用方法.重点总结了废旧PET化学回收法和生物回收法的解聚反应机理和应用情况,介绍了光驱动分解、微波辅助分解和废旧PET的高附加值利用创新方法,分析了不同回收方法的优势与局限性,提出了废旧PET回收循环利用未来可能的发展方向.     

废旧聚酯化学回收法及其再生产物的应用研究进展

化学回收法作为一种能最大程度回收废旧聚酯(PET)以及实现其闭环回收的方法而受到广泛关注。对废旧PET的化学回收方法及其回收再生的PET在不同领域的应用进行了综述，总结了现有的化学回收工艺及其特点。最后提出未来可以从机制层面深入，将较为成熟的降解技术与新兴的技术、助剂结合，进一步提高再生产物的品质，将废旧PET变废为宝，希望为废旧PET回收技术的研究探讨提供一定的参考。     

废旧PET固相增黏回收工艺探索

PET材料在透明塑料领域中价格低廉,且综合性能较好,我国每年废旧PET的产生量非常大,由于PET在自然环境中很难降解,为了减少其对环境的影响,迫切需加大废旧PET的循环利用。目前废旧PET回收工艺主要有物理回收和化学回收2种。制约废旧PET循环使用的主要瓶颈是特性黏度太低,因此研究PET回收增黏工艺对提升废旧PET的回收利用,减少其对环境的影响,具有重要意义。     

废旧PET回收利用进展

聚对苯二甲酸乙二醇酯(PET)是目前使用最广泛的半结晶热塑性聚合物之一,由石化产品制得,生产过程中需要耗费巨大的资源.由于PET化学性质稳定,自然环境下很难降解,废弃材料的不恰当处理导致生态环境问题日趋严重.该文通过对比废旧PET的不同回收利用方法(包括能量回收、物理回收、化学回收、生物回收等)特点、产物、应用场合等,...     

PET的再生利用技术

综述了近年国内外在废旧PET瓶回收利用方面的最新研究进展，总结了废旧PET瓶回收利用的主要方法和其污染物的问题，分析了今后我国废旧PET瓶回收利用技术的发展趋势和应采取的措施，指出了废旧PET回收利用的重要性。     

中科院过程所开发PET降解技术

日前,废旧高分子产品回收利用技术与示范中期检查会在天津召开。中科院过程工程所离子液体清洁过程与节能创新团队吕兴梅研究员汇报了废旧聚对苯二甲酸丁二酯(PET)绿色降解与环保级再利用技术课题的研究进展。
　　该课题针对我国废旧PET化学回收反应速度慢、选择性低和单体难分离等问题,开发基于新型功能化离子液体的催化降解PET并回收利用的新技术。课题组通过对离子液体降解PET反应过程的系统研究、放大规律的揭示、全系统的优化集成,建立了离子液体催化降解PET示范装置,形成了基于离子液体绿色介质的温和高效催化降解废旧PET的核心绿色新工艺。该课题与项目其它课题,如废旧橡胶、涤纶等回收利用技术共同构成一个完整的废旧高分子材料的高值化利用共性技术平台。目前,课题组已完成离子液体催化剂的规模化制备,建立了间歇式／连续式两套模式试验装置,申请国际发明专利1项,中国发明专利3项。     

PET瓶回收应用进展

介绍了国内外废旧PET瓶通过物理或化学回收方法制取再生薄片、粒料、纤维、片材、泡沫塑料、复合材料、涂料等的应用进展；另外，对于闭环循环的PET“瓶-瓶”回收工艺技术进行了专门介绍。     

废弃聚酯化学回收再生利用的方法

简要介绍了废弃聚酯(PET)化学回收利用方法的发展现状,重点介绍了糖解、醇解、水解等化学回收方法及其优缺点,以及目前商业化的化学回收法———复合降解法工艺,对利用市场需求来推动化学法回收PET的商业化发展进行了展望。     

增黏回收PET专用扩链剂研究进展

随着聚对苯二甲酸乙二醇酯(PET)的应用量不断扩大,对其进行回收利用已成为热门课题之一。废旧PET可以经过扩链增黏后直接再利用,可以通过与其他聚合物材料共混提高相应性能再利用,也可以降解制备对苯二甲酸及其酯类单体,还可以经进一步降解再转化为高附加值精细化学品。本文就化学扩链增黏回收PET技术从专用扩链剂角度进行了评述。     

玻璃钢废旧料回收处理方法

改革开放以来,我国玻璃钢行业快速发展,同时产生的大量的玻璃钢废旧料对环境的污染也日益严重。常规的焚烧掩埋处理方法处理量低、容易造成二次污染等,已无法满足当今环保要求。因此,通过对玻璃钢废旧料回收工艺的不断研究,现有的回收工艺主要分为物理回收工艺、化学回收工艺和能量回收工艺。物理回收及化学回收旨在回收利用玻璃钢废旧料的主要组成,通过粉碎、热解等方法实现了玻璃钢废旧料的资源化。而能量回收主要回收玻璃钢废旧料自身能量,通过燃烧等方式实现能源的重复利用。     

PET降解研究进展

介绍了国内外开发的聚对苯二甲酸乙二醇(酯PET化)学解聚的工艺方法,包括水解法、甲醇解聚法、乙醇解聚法、乙二醇解聚法等,对主要的化学解聚方法的优缺点进行了综合比较,指出我国应该加强PET解聚技术的研究以,彻底解决资源紧张和白色污染问题。     

PET瓶回收技术进展

介绍了目前国内外PETPET瓶的使用和回收概况。简述了PET瓶的解聚、扩链等化学回收方法以及简单回收、溶解／再沉淀法和熔融挤出法等物理回收方法的最新技术进展。     

废弃PET化学回收及制备不饱和聚酯树脂的研究进展

随着聚对苯二甲酸乙二醇酯（PET）材料用量的大幅增长,大量废弃PET制品堆积造成的环境污染问题日益突出,其回收利用技术也随之广受关注。在不同的PET回收方法中,将PET降解为单体或低聚物的化学回收是效率最高、产物利用价值最大的方法,但也存在反应条件苛刻、产物收率低等问题。本文详细梳理了水解法、甲醇醇解法、二元醇醇解法、胺解法和氨解法等化学回收方法的主要特点以及微波加热、离子液体、纳米技术等新兴技术在PET化学回收过程中的应用概况。通过对各种化学回收工艺的比较,文中得出二元醇醇解法是最具商业应用价值方法的结论。在此基础上,文中重点介绍了PET的二元醇解以及进一步制备不饱和聚酯树脂的化学过程、发展现状、制约因素和改进措施。分析表明,由PET二元醇解产物制备不饱和聚酯树脂是提高废弃PET资源化效率、丰富原料供给、推动产品升级的重要途径,开发高效、廉价、环保的新型催化剂或酶催化技术是废弃PET回收领域今后主要的发展方向。     

Glycolyzed PET waste and castor oil‐based polyols for two‐pack coating systems

Useful coating products may be obtained by chemical valorization (glycolysis) of post‐consumed poly(ethylene terephthalate) (PET) wastes. Glycolysis of PET waste was carried out using poly(ethylene glycol) (PEG) of various molecular weights (200, 400, 600). The depolymerized oligoesters obtained were transesterified with castor oil which results in the formation of saturated hydroxyl‐functional polyester polyols. Two‐pack coating systems were formulated using these resins as base component and melamine formaldehyde resins as hardener component. Cured films were tested for their mechanical and chemical performances. The glycolysis of PET using PEG and polyester polyol formation was characterized using Fourier transform infrared spectroscopy and the molecular weights were determined using gel permeation chromatography. Copyright © 2006 Society of Chemical Industry     

废聚酯的循环利用

废聚酯可通过化学解聚等手段来实现其循环利用。阐述了废聚酯循环利用领域的研究现状。介绍了目前国内外开发的废聚酯循环利用工艺方法，其主要方法有水解法、甲醇解聚法、乙二醇解聚法等。     

过渡金属Mn取代多金属氧簇催化醇解废旧PET

合成了一种具有三明治结构的过渡金属Mn取代的多金属氧簇(POMs)催化剂Na12[WZnMn2(H2O)2(ZnW9O34)2],用于催化聚对苯二甲酸乙二醇酯(PET)的醇解过程,对反应温度、反应时间和催化剂量等实验条件进行了优化。结果表明,在催化剂量为PET质量的1.0%、质量比PET/EG(乙二醇)为1:4及190℃的条件下反应80 min,PET降解率可达100%,对苯二甲酸乙二醇酯(BHET)的收率达84.42%。     

Synthesis and characterization of novel polyurethanes based on aminolysis of poly(ethylene terephthalate) wastes,and evaluation of their thermal and mechanical properties

BACKGROUND: Much research is currently directed towards recycling post‐consumer poly(ethylene terephthalate) (PET) products for both environmental and economic reasons. Aminolysis of PET wastes using different amines, such as allylamine, morpholine, hydrazine and polyamines, leads to different reaction products as diamides of terephthalic acid, which do not possess any potential for further chemical reactions. In the past, the use of ethanolamine has been investigated for the aminolytic degradation of PET waste in the presence of different simple chemicals such as sodium acetate as catalysts. The product obtained, bis(2‐hydroxyethylene) terephthalamide (BHETA), has potential for further reactions to obtain useful products. Nevertheless, there has been no report on using recycled BHETA from PET to synthesize polyurethanes. RESULTS: In this research the product of aminolysis of PET waste, BHETA, was prepared. Then novel polyurethanes were synthesized based on the BHETA prepared, 1,4‐butanediol, ether‐type polyol and various molar ratios of hexamethylene diisocyanate. To evaluate the effect of BHETA, the properties of the polyurethanes without and with BHETA were compared. Fourier transform infrared spectra, thermal transitions, degradation, swelling ratio and chemical resistance of the synthesized polyurethanes were investigated. Also, the polyurethanes were applied as adhesives on various substrates. Comparison of the maximum bond strength of the synthesized polyurethane to that of commercial adhesives shows an about 2.2‐fold increase. CONCLUSION: It is possible to synthesize new polyurethanes with interesting properties using BHETA as an aminolysis product of PET waste. These kinds of materials have potential for many applications, such as adhesives and coatings. Copyright © 2008 Society of Chemical Industry     

Recycling PET beverage bottles and improving properties

Recycling PET from bottles has been carried out by three different extrusion methods. Under optimized processing conditions, a virgin poly(ethylene terephthalate (PET), recycled PET and a mixture of virgin and recycled PET, with and without the modifier polypropylene functionalized with maleic anhydride [PP‐graft‐MA]), were processed. Different methods were used to characterize the processed products. The results showed that the intrinsic viscosity and molecular weight decreased as the blend ratio of recycled PET was increased. This was due to thermal exposure as well as shear degradation of recycled PET. Thermal cycles of the processes used for recycling PET and its blending specimens with virgin PET show the importance of the thermal treatment in the improvement of mechanical strength and increased crystallinity. Nevertheless, the properties of the functionalized blends were improved. This behaviour is attributed to a series of chemical and physico‐chemical interactions taking place between the two components. Copyright © 2004 Society of Chemical Industry     

纤维素辐照改性及其应用

辐照技术利用电离辐射诱发物理化学反应(例如交联、聚合、接枝、降解等)对材料进行加工或改性,与常规加工方法相比,具有节能、无环境污染等特点。将辐照技术应用于纤维素改性过程近年已成为非动力核技术应用领域研究的热点之一。本工作对目前纤维素的辐照技术及其基本反应机理进行了概述,其中包括纤维素膜材料、纤维素水凝胶、纤维素微晶/纳米材料,并对纤维素辐照改性过程的辐照环境,包括溶剂、敏化剂、温度、辐照剂量、环境氛围、结晶度等进行了总结。