【作者】 史君；

【导师】 段雪；

【作者基本信息】 北京化工大学 ， 应用化学， 2009， 博士

【摘要】 聚对苯二甲酸乙二醇酯(polyethylene terephthalate,简称PET)成本低且性能优异,在包装业、电子电器、医疗卫生、建筑、汽车等领域得到了广泛应用。但是,PET在使用过程中存在着刚性强、韧性差、结晶速率低等缺点。利用化学改性技术研究开发改性PET,获得具有优异性能的新型聚酯品种,扩大聚酯产品新的应用领域,这方面的工作引起了国内外学术界和产业界的高度重视。本文首先以对苯二甲酸(PTA)、乙二醇(EG)、1,4-环己烷二甲醇(CHDM)为基本原料,采用熔融缩聚方法,通过研制新型催化体系,合成制备了CHDM改性的共聚酯(PETG或PCTG)。然后,以PETG为基础,通过熔融共混的工艺路线,制备得到了PC/PETG、ABS/PETG、PET/PETG及PPS/PETG等合金材料。同时,提出采用氧化铝溶胶为原料,通过原位聚合的工艺路线制备得到了氧化铝溶胶改性PET材料。论文对上述材料的形态结构、结晶行为、热性能及力学性能等进行了研究。论文共分三个部分：1、CHDM改性共聚酯合成及性能研究。2、PETG共聚酯的合金制备及结构性能研究。3、氧化铝溶胶改性PET合成与性能研究。本文的创新点和研究结果如下：1、本文研制的CHDM改性共聚酯合成用催化体系和提出的合成工艺均未见国内外报道。研制出适合在直接酯化法合成工艺使用的新型高效催化复合体系,所制备的共聚酯切片色相b值良好,特性粘度高,产品主要质量指标达到了国外先进技术水平；采用醇解PET制备母液常压下进行PETG酯化反应的先进工艺,适于在PTA法聚酯工业装置上推广使用,基于自主研发的PETG共聚酯材料,通过PETG共聚酯加工性能的系统评价,发现并证明所研制的PETG共聚酯产品可以替代进口产品在国内推广使用。2、以PETG为基础,提出了改善PC/PETG、PET/PETG、ABS/PETG、PPS/PETG四种合金材料性能的设计思路并经系统研究获得成功。在PC/PETG合金材料的研究中,利用PC与PETG的相容性好的特点,改善了PC的应力开裂性和加工性能,通过部分取代PC,降低了PC相关产品的成本；在PET/PETG合金材料的研究中,针对PET在制备工程塑料时具有刚性强韧性差的缺点,改善了PET的韧性；在ABS/PETG合金材料的研究中,部分取代在汽车和电子电器行业广泛使用的PC/ABS材料,降低了高档工程塑料的成本；在PPS/PETG合金材料的研究中,通过对其结晶行为的研究,发现了PETG对PPS结晶性能的主要影响因素。3、提出了以氧化铝溶胶改性PET提高热性能的工艺方案。PET作为包装材料使用的瓶颈问题是需要进一步提高其耐热性,目前的原位聚合技术通常是添加纳米二氧化硅和蒙脱土,目前国内外文献中还未见有相关氧化铝溶胶改性PET方面的报道。本文采用原位聚合制备氧化铝溶胶改性PET,PET的玻璃化转变温度从72℃提高到87℃,同时PET的结晶速率显著提高。更多还原

【Abstract】 Polyethylene terephthalate (PET) has been widely used in package, electronic, health and medical,construction, and automobile fields with its low cost and high performance.However, there still exist some shortcomings such as hard rigidity, poor toughness and low crystallization rate for PET. Modified PET through chemical route can endow new-type polyesters with excellent performances and expansive applications of polyester products with good prospects.In this thesis, PET modified with CHDM(1,4-cyclohexane dimethanol) co-polyester (PETG or PCTG) was first prepared by using terephthalic acid (PTA), ethylene glycol (EG) and 1,4-cyclohexane dimethanol (CHDM) as raw materials through melt polycondensation method. Then, PC/PETG, ABS/PETQ PET/PETG, PPS/PETG and other alloy materials were fabricated by melt blending process route.Besides, alumina sol (Al2O3) modified PET material was synthesized by using in-situ polymerization process.The morphology, structure, crystallization behavior, mechanical and thermal propertied of the above-mentioned material were studied. The thesis is divided into three parts:1.Synthesis and properties of co-polyester modified with CHDM.2.Preparation, structural and properties of PETG co-polyester.3.Synthesis and characterization of modified PET with alumina sol.The innovation results of above research are listed in the following:1.Novel catalytic system and synthesis route were created for the copolyester modified with CHDM. The new highly efficient catalytic system is suitable for the direct esterification process, making polyester chips with good color shade of b value, high intrinsic viscosity. The product quality can achieve the criterion of foreign advanced product. The PETG esterification technology triggered by using PET alcoholysis mother liquor at atmospheric pressure is suitable for industrial application. Based on the independent research and development of the PETG copolyester material, the systematic evaluation of PETG copolyester processing performance showed that PETG co-polyester products can replace the imported products in domestic.2.This design idea, which properties improvment of four kinds of alloys for PC/PETG, PET/PETQ ABS/PETG and PPS/PETG were proposed through blending on the basis of PETG,and the purpose was obtained by systematicly research. For the PC/PETG alloy, the use of PC and PETG has good compatibility to improve PC stress cracking and processing performance,and reduce the product cost through the partial replacement of PC.For the PET/PETG alloy, the toughness of PET is improved. For the ABS/PETG alloy, the partial replacement of PC/ABS material in the automotive and electrical industry can reduce the high-grade engineering plastics cost. For the PPS/PETG alloy, the influence of PETG on the crystallization behavior of PPS was studied.3.The project about improvement of PET thermal performance by PET modified with alumina sol was proposed. PET developed toward package material is rather limited, due to its thermal resistance. Currently in-situ polymerization technology refers to addition of SiO2 Nanocomposites and MMT. There is not reported that PET is modified with alumina sol according to the international literature.In this paper, in-situ polymerization technology of PET modified with alumina sol was adopted. The glass transition temperature of the modified PET increases from 72℃to 87℃and the crystallization rate significantly improved.更多还原