【作者】 张臣；

【导师】 赵建青；

【作者基本信息】 华南理工大学 ， 高分子化学与物理， 2009， 博士

【摘要】 不饱和聚酯树脂(Unsaturated Polyester Resin,UPR)是热固性树脂中发展较快的品种之一,也是用量最大的热固性树脂。它具有优良的机械性能、电性能和耐化学腐蚀性能,可常温常压固化,原料易得,加工工艺简便。近年来,我国UPR的生产量保持着年均近两位数的增长,发展迅速,但是国内绝大多数企业由于技术原因,只是生产中低端通用型UPR产品,在国际市场无优势,亟需开发新产品来提升竞争力。同时,随人们对环境污染问题认识的深入,国际相关环保法规日益严格,UPR产品的发展在具备高性能要求的同时,向绿色环保趋势发展。为解决长期困扰阻燃UPR产品含卤素和添加阻燃剂损伤UPR性能等问题,本论文对无卤UPR/SiO2纳米复合物制备和含磷反应型阻燃UPR的合成进行了研究。(1)以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和异氰酸基三亚甲基硅烷(ICTEOS)的加成产物(DI)为阻燃剂,将其溶解到UPR预聚物中,利用反应过程中的溶胶-凝胶反应制备得到透明的UPR/SiO2纳米复合物(UPR-DI)。由于DI演变而成的纳米SiO2结构带有苯环和氨基,氨基与UPR分子链上的-C=O之间能形成氢键,使网络状纳米SiO2最终能均匀分散在聚酯基体中。经FTIR、DSC、SEM及EDS对其结构进行了表征,表明形成了均一的纳米复合物。随DI用量由0增至20%,UPR-DI的极限氧指数(LOI)由19升至29,阻燃性能明显增强。分别测试了UPR-DI在空气氛和氮气氛中的TG曲线,利用Ozawa法求解活化能,发现DI用量为10%的UPR/SiO2纳米复合物(UPR-DI10)在热分解转化率大于5%时,较纯UPR具有更高的热分解活化能(Ea)。动态力学分析(DMA)分析结果表明,纳米SiO2在整个体系中起到增强作用,使UPR-DI20的储能模量E’比UPR高。(2)选用甲基磷酸二甲酯(DMMP)为阻燃剂,比较了反应型(“一步法”和“两步法”)和添加型(共混法)两种方式制备无卤阻燃UPR的差别,结果表明“一步法”为制备一种反应型含磷阻燃UPR(P1-UPR)的较佳方法。31P-NMR结果表明DMMP通过酯交换的方式连接到P1-UPR分子主链上。TG-FTIR对热分解气体的分析未发现含磷基团的特征吸收峰,SEM对不同DMMP用量的P1-UPR燃烧后的残留炭进行分析,结果表明随含磷量的增加,残留炭层趋向完整致密。综合两者结果说明,P1-UPR中所含磷主要通过凝聚相阻燃机理来增强阻燃效果。(3)以苯基磷酰二氯为起始原料,合成了阻燃剂BPHPPO和BHEPP,进而制备了两种主链含磷的UPR——P2-UPR和P3-UPR。随阻燃剂用量的增加,P2-UPR和P3-UPR的LOI值及垂直燃烧等级依次增加。TG和DTG分析结果表明,随反应物中BPHPPO用量由0增加至30%,其5%失重温度由275.5℃降至248.0℃。然而,P—O—C键的提前分解促使磷酸类物质的生成并有效阻碍了树脂的进一步分解,空气氛下600℃时残留炭量由0增至4.6%。采用M. R. Kamal模型分别研究了P2-UPR和P3-UPR的固化动力学特征,结果表明,引入BPHPPO后,P2-UPR1与纯UPR相比,出现固化延迟效应,固化反应的活化能由46.5 kJ/mol升至142.4 kJ/mol,且随BPHPPO用量增加而持续增大。而采用不含酚羟基的阻燃剂BHEPP合成的P3-UPR则无固化延迟效应。(4)合成了两种较高热稳定性的磷杂菲类阻燃剂DOPO-MA和DDP,利用元素分析、FTIR和1H-NMR等进行了结构表征,并将它们与马来酸酐、邻苯二甲酸酐及1,2-丙二醇进行缩聚反应,分别制备了P4-UPR和P5-UPR。在热稳定性方面,P4-UPR与纯UPR相当,而P5-UPR则高于纯UPR。P5-UPR在常温下具有与纯UPR相当的电气强度(22～25 MV/m),在155℃比纯UPR下降了6～7 Mv/m。DDP用量为30%的P5-UPR3的阻燃等级可达到UL 94 V-0级。锥形量热测试仪测试结果表明,与纯UPR相比,含磷1.62%的P5-UPR3的最大热释放速率(PHRR)为375kW/m2,降低了42.7%;总释放热(THR)为83 kJ,比纯UPR降低43.2%;有效燃烧热(EHC)下降至纯UPR的40.7%。利用外推法得到P4-UPR3在MEKP+异辛酸钴引发体系下的固化反应工艺参数为:凝胶温度84℃,固化温度103℃,后处理温度121℃。利用Malek方法对P5-UPR和纯UPR的固化动力学过程进行模拟,所得反应动力学模式方程分别为:更多还原

【Abstract】 Unsaturated polyester resin (UPR) is one sort of thermosetting resins with rapid development, and the amount of usage of UPR is the biggest in thermosetting resins. Raw material for UPR is easily available, and it can be solidified by simple process technique at normal temperature and pressure. UPR shows excellent mechanistic, electrical properties and good chemical corrosion resistance. In recent years, the development of UPR is very rapid and output keeps a double-digit growth in our country. However, due to the technical problem, most of domestic corporations just manufacture mid/low-grade products, which have no predominance in international market. So developing new UPR products to promote competitive power is a problem to be solved immediately. At the same time, with the deep recognition of environmental contamination and gradual establishment of corresponding environmental protection laws, green and environment-friendly concept has been emphasized in the research of high performance UPR.Since flame-retardant UPR containing halogen destroys environment and the additive flame retardant results in the performance loss, to solve the problem, preparation of UPR/SiO2 nanocomposite and synthesis of novel phosphorus-containing UPR have been studied in this thesis.(1) A novel phosphorus-containing unsaturated polyester resin/SiO2 hybrid nanocomposite was prepared from the in-situ sol-gel curing of UPR and triethoxysilane (DI) which was synthesized by the nucleophilic additional reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) and 3-(trieoxysilyl) isocyanate(icteos). Since the structure of nano-SiO2 derived from DI contains phenyl and amino group, which can form hydrogen bonds with–C=O bond on the UPR chain, nano-SiO2 networks can homogeneous disperse in UPR. The structure of SiO2 /UPR nanocomposite was confirmed by FTIR, DSC, SEM and EDS. With the increase of DI contents from 0 to 20%, the limiting oxygen index (LOI) value of the cured UPR-DIs raised from 19 to 29, suggesting a significant improvement in flame retardance. Thermogravimetric analyses (TGA) both in air and in nitrogen were used to estimate mechanism of thermal degradation, and activation energies (Ea) of different degree of conversion (α) were calculated by Ozawa’s method. The UPR-DI containing 10%DI (UPR-DI10) had higher Ea than that of the pure UPR asα>5%. DMA results revealed that nano-SiO2 enhanced strength of the whole system and made the storage modulus higher than that of UPR.(2) With DMMP as flame retardant, the method of one step and two steps for preparing reactive flame-retarded UPR and the method of blending for preparing additive flame-retarded UPR were discussed. The results showed that one step method was the best for reactive flame-retarded P1-UPR. 31P-NMR confirmed that DMMP was imported into the main chain of P1-UPR by ester exchange reaction. Characteristic absorption peaks of phophorus-containing groups did not appear in the TG-FTIR for thermal degraded gas from P1-UPR. Char residues of burned P1-UPR with different usage of DMMP were analyzed by SEM. The results revealed that the layer of char residues became compact with increasing of phosphorus. These results indicated that phosphorus flame-retarded P1-UPR by condensation mechanism.(3) Bis-phenoxy (3-hydroxy) phenyl phosphine oxide (BPHPPO) was synthesized by phenyl phosphonic dichloride and resorcinol, and bis(hydroxyethyl)phenylphosphonate (BHEPP) was synthesized by phenyl phosphonic dichloride and ethylene glycol. P2-UPR and P3-UPR were prepared by condensation reaction with BPHPPO and BHEPP as flame retardant, respectively. UL94-V0 rating and limiting oxygen index (LOI) increased with the increase of flame retardant in the cured P2-UPR and P3-UPR. TG and DTG analysis indicated that decomposition temperature of 5% weight loss decreased from 275.5℃to 248.0℃with increase of BPHPPO content from 0 to 30% in P2-UPR. However, formation of phosphorus-containing acid from the decomposition of P—O—C bonds interfered effectively the further polymer decomposition. And the char residues increased from 0 to 4.6% at 600℃. Curing kinetic parameters of P2-UPR and P3-UPR were calculated by Kamal’s equation using DSC. Compared with pure UPR, retarded effect of P2-UPR happened after the introduction of BPHPPO. Values of Ea increased from 46.5kJ/mol to 262.9kJ/mol with increasing of mass fraction of BPHPPO in P2-UPR from 0 to 18%. While the retarded effect didn’t exist in P3-UPR which was synthesized by BHEPP without phenolic hydroxyl group.(4) DOPO-MA and DDP were synthesized by 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) with maleic acid(MA) and itaconic acid(ITA), respectively. P4-UPR was obtained by reacting PG with MAH, PAH and DOPO-MA, and P5-UPR was obtained by reacting PG with MAH, PAH and DDP. The chemical structures of these compouds were confirmed by EA, FTIR, 1H-NMR and 31P-NMR. The thermal stabilities of P4-UPR and P5-UPR were studied by thermogravimetric analysis (TGA). The results showed that the thermal stability of P4-UPR was close to that of pure UPR, but P5-UPR had higher thermal stability than pure UPR. The electric strength of P5-UPR was almost the same as that of pure UPR(22-25MV/m) at room temperature, while it was 6-7MV/m less than that of pure UPR at 155℃. The flame retardance of P5-UPR3 with the usage of 30% DDP could reach UL 94 V-0. The results of cone calorimeter showed that, in P5-UPR, an increase of phosphorus content from 0 to 1.62% decreased PHRR values from 655 to 375kW/m2 (a 42.7% reduction) and THR values from 146 to 83kJ (a 43.2% reduction). EHC was reduced to 40.7% of the control sample (UPR). With MEKP and cobalt isooctoate used as initiator system, calculated curing conditions for P4-UPR3 were as follow: Tgel =84℃,Tcure = 103℃,and Ttreat = 121℃. Curing kinetics of P5-UPR3 was researched by Malek model. The cure kinetic function could be described using S-B model in the function of f(a)1 =a0.82×(1-a)1.25, and the function for pure UPR was f(a)2 =a0.41×(1-a)0.84。更多还原