【作者】 夏宇正；

【导师】 焦书科；

【作者基本信息】 北京化工大学 ， 材料学， 2002， 博士

【摘要】 热塑性弹性体（TPE）因可采用塑料成型方法进行加工，不仅能耗低而且材料可重复利用，因此其发展速度极快，迄今其产耗量已占橡胶材料的20％。但因众多TPE为物理交联或离子交联，因而与传统的热固性橡胶相比，存在力学性能差、耐热温度低和永久变形大等缺点。因此寻求一种既具传统热固性橡胶C—C、C—S或—S—S—共价交联键，又可进行热塑加工的共价交联的反应和方法对制备力学性能优异的TPE至关重要。解决这一问题的有效方法之一是利用环戊二烯（CPD）和双环戊二烯（DCPD）之间的Diels-Alder热可逆转化反应，将DCPD环引作线型聚合物的交联键，制取—C—C—共价交联的聚合物以提高其力学性能，并利用DCPD在≥170℃解二聚形成带CPD侧基线型分子的性质赋予其热塑加工特性。本研究以环戊二烯二酸盐衍生物作热可逆共价交联剂，通过与聚氯乙烯（PVC）、氯化聚乙烯（CPE）、氯醚橡胶（CER）和丙烯酸酯橡胶（ACM）等含氯聚合物的脱MX酯化反应来实现共价关联，并制取相应的新型TPE。研究了交联剂的制备和混合方法、交联反应的性质和速度、最适配方和工艺、热可逆转化行为及所得共聚物的加工和性能。主要研究内容和结果如下： （1） 首次以碱法（NaOH）取代金属钠法制备中间体CPDNa，该方法不仅操作安全，而且收率和产品纯度均达到金属钠法的水平。并研究了CPDNa与CO₂反应制备DCPD（COOH）₂及其盐的合成条件（气固态CO₂）和反应规律。为了使固相反应更易均匀混合，提出了交联剂颗粒的细化和交联剂母粒的制造方法。 （2） PVC（软、硬）的共价交联。通过熔融反应、模压和注射成型，研究了热可逆交联剂DCPD（COOH）₂及其盐与聚氯乙烯（PVC）的交联反应时，交联剂种类与用量、催化剂种类与用量、助催化剂聚醚分子量大小对交联程度、力学性能、耐热性与热稳定性、流动性能等的影响。结果表明，季胺盐和聚醚醇催化剂可促进PVC的交联，交联PVC的 北京化工大学博士学位论文流变特性与PVC相近，所得产物不仅性能（软制品的耐热性提高10一巧℃、伸长率提高60%）有所改善，而且具有热可逆性，反复加工次数可达三次以上。并分析了产物中存在少量不可逆结构的成因。 （3）研究了CPE的热可逆共价交联反应。以溶液反应法研究了CPE与DCPD（COOK）:的交联反应，制得了凝胶量在80%以上的共价交联CPE，考察了不同牌号CPE（含氯量不同）、催化剂及其用量、反应温度、反应时间及其交联剂用量对CPE凝胶形成量的影响;通过对比实验和IR谱图证明了该凝胶确由CPE与DCPD（COOK）:经双端醋化反应生成;通过反应溶解性实验验证了共价交联CPE的热可逆转化特性。 （4）以共混反应法研究了双环戊二烯二梭酸钾与CPE的熔态交联反应，考察了共混反应温度、共混反应时间及交联剂用量对其物性的影响，成功地制得了物性达到常规硫化胶的CPE一TPE，产品经三次重复加工后，其物性随加工次数增多还略有提高，从而开发出既具常规硫化胶物性、又可热塑加工得到高性能新型CPE一TPE的制造方法，为CPE一TPE的产业化提供一类简捷易行、工序少、产效高的新方法。 （5）研究了CER在溶液中与DCPD（COOK）:的交联反应，制得了凝胶形成量高达88%的凝胶，得出了交联反应速度随反应温度提高、交联剂用量和催化剂用量的增大而加快的规律。用IR证明了凝胶形成机理是DCPD（C 00K）:与CER发生双端酷化反应。反应溶解性实验证明了交联的凝胶具有热可逆转化特性。 （6）将DcPD（COoK）:用于丙烯酸酷橡胶混炼体系，以共混反应模压法、挤出反应法，制得了物性接近常规硫化胶，且胶料经三次重复加工后，物性基本不变的新型TPE，开发出一条简捷易行、工序少、产效高、易于生产转化的制造新型ACM一TPE的新方法。 本研究提出了含氯聚合物的交联改性新方法，证实了共价交联结构具有热可逆转化特性，验证了DCPD衍生物对含氯聚合物实施共价交联的普适性，实现了既具共价交联“硫化胶”物性又可塑性加工的新型TPE的预期目标。更多还原

【Abstract】 It is well known that thermoplastic elastomer(TPE) can be easily processing by means of the processing methods of general plastic materials. Therefore, TPEs have been developed fast in the past decades. However, compared with thermosetting rubbers, most TPEs still have many disadvantages, for example, low mechanical properties, great creep deformation, low heat resistant, due to their crosslinked linkage and sites are based on physical or ionic crosslinkage. To find a new kind of crosslinking reaction method in order to improve their performance is a very important research title. By using the thermal reversibility between cyclopentadiene and di-cyclopentadiene was one of the effecting way, which can form C - C covalent crosslinking bonds as in traditional vulcanized rubber.In this paper, the thermally reversible crosslinking reaction and the properties of synthesized TPE based on the reactions of chlorine containing polymers such as PVC , chlorined polyethylene (CPE ) , epichlorohydrin rubber(CER) and acrylic rubber(ACM) with salts of dicyclopenladienyl dicarboxylate crosslinking agents were studied. All the results are showed as follows:(1) Cyclopentadienyl sodium(CPDNa) was prepared successfully via reaction CPD with NaOH instead of Na, and the effects on CPDNa’s yield were studied in detail, so the optimum reaction conditions were achieved. DCPD(COOH)2 was synthesized via the reaction of CC>2(gas) with CPDNa contrast to the method using solid COi- The effects on the product’s yield and purity were also discussed. The salt derivatives of DCPD(COOH)2 was obtained by the reaction of DCPD(COOH)2 with KOH, NaOH, NH4C1 and metal oxides. The methods for fined crosslinker and the masterbatch of crosslinking agent were put forward.(2)The crosslinking reaction of PVC with DCPD(COOH)2 derivatives was studied by melting reaction, compression mold, and injection mold. The relations between the amount of the agent and crosslinking degree, mechanical property, heat resistent,thermal stability and pyrofluxibility were studied in detail. The results indicted that the crosslinking speed and degree of PVC with crosslinking agent can be prompted via ammonium catalyst, and polyethylene glycol was an excellent accelerator to this crosslinking reaction. The crosslinking products not only processed improved property and thermally reversible property, but can be reformed more than three times. The thermally reversible covalent bonded PVC-TPE with high performance soft PVC were obtained.(3) Potassium salt of dicyclopentadienyl dicarboxylate (DCPD(COOK)2 ) was applied to CPE as crosslinking agent and a crosslinked product with 81.79% gel content was obtained in solution reaction. The effects of kinds of CPE , catalysts and their dosage , temperature, reaction time and the dosage of crosslinking agent on the gel content were studied. It was proved by IR that the gel was generated through esterification between the chlorine-carbon of CPE and the carboxylic salt groups of the crosslinking agent. It was also important that the addition of phase transformation catalyst in CPE system. The crosslinked CPE exhibited thermally reversible behavior due to the dimmer (dicyclopentadiene) /monomer (cyclopentadidne) conversion of -DCPD- moieties via reversible Diels-Alder cycloaddition; The TRTPE’s, based on CPE , mechanical properties such as tensile strength and elongation were closed to that of thermosetting CPE cured with normal vulcanizator. The TRTPE of CPE could be reformed for three times and the mechanical properties after reformation kept unchanged. .(4)The DCPD(COOK)2 was also used in ACM mixed system. The results showed that the new TPE with thermally reversible covalent bond were also obtained ,the gained TPE can be reformed for three times and its mechanical properties after reformmation kept uncharged. Therefore a industrialized method with few equipment and simple procedure was developed.In a word, all the studies in this paper established a new crosslinking method to improve the PVC’s property and to prepare a new class更多还原