共查询到20条相似文献,搜索用时 171 毫秒
1.
2.
采用苯酚和37%甲醛水溶液为原料并以30%氢氧化钠溶液为催化剂制备了高羟甲基含量、低残留甲醛和工艺稳定的热固性酚醛树脂。通过测试合成的树脂中游离酚、游离醛和羟甲基含量研究了醛、酚物质的量比(F/P)、催化剂用量、反应时间和反应温度对酚醛树脂合成的影响,并通过傅里叶变换红外光谱对合成树脂的结构进行了分析。结果表明:当F/P=1.5,催化剂添加质量分数为5%,反应时间2.5 h,反应温度85℃时,制备的树脂性能最佳,其羟甲基含量最高,树脂活性最大,主要为高邻位结构。 相似文献
3.
以苯酚、甲醛为原料,在催化剂的作用下合成酚醛树脂,然后用硼酸改性得到硼酚醛(FB)树脂.采用FB树脂作为基材树脂制作玻璃布层压板,FB树脂的耐热性比普通酚醛树脂高.FB树脂层压板具有好的耐热、阻燃、机械和电气性能,其阻燃性能达到了UL-94垂直燃烧法V-0级. 相似文献
4.
通过钛酸四丁酯与热塑性酚醛树脂(Novolac树脂)的酯交换反应合成了一类快速固化型杂化酚醛树脂,可加入六亚甲基四胺进行固化。通过红外、核磁、凝胶时间和粘度等测试研究了树脂的分子结构和理化性能。结果表明:随着钛酸四丁酯用量增大,杂化酚醛树脂的分子质量明显增大,凝胶时间缩短,杂化酚醛树脂溶液的粘度增大,并基本呈线性关系。钛酸酯键有效改进了酚醛树脂的粘接性。固化速率的加快来源于改性树脂分子质量的增大和钛酸酯结构对于固化反应的催化作用;而杂化酚醛树脂粘接性的提高是由于酚醛树脂中的钛酸酯结构起到了偶联剂作用。 相似文献
5.
6.
在合成酚醛树脂的过程中引入有机硅预聚物和硼酸,制得硼硅酚醛树脂,并在此基础上加入正硅酸乙酯,原位水解生成SiO2,进一步改性了硼硅酚醛树脂。分别考查了有机硅预聚物、硼酸和正硅酸乙酯加入量对改性酚醛树脂粘接强度的影响。通过IR考查了改性树脂的结构,硼氧键和硅氧键成功地引入到酚醛树脂中。还通过DSC和不同条件下粘接强度的测试考查了改性树脂的固化性能,确定了其固化工艺。空气气氛中的热重分析则表明改性酚醛树脂初始分解温度为475℃,1000℃残炭率为21%,耐热性明显优于普通酚醛树脂。 相似文献
7.
在合成酚醛树脂的过程中引入有机硅预聚物和硼酸,制得硼硅酚醛树脂,并在此基础上加入正硅酸乙酯,原位水解生成SiO 2,进一步改性了硼硅酚醛树脂。分别考查了有机硅预聚物、硼酸和正硅酸乙酯加入量对改性酚醛树脂粘接强度的影响。通过IR考查了改性树脂的结构,硼氧键和硅氧键成功地引入到酚醛树脂中。还通过DSC和不同条件下粘接强度的测试考查了改性树脂的固化性能,确定了其固化工艺。空气气氛中的热重分析则表明改性酚醛树脂初始分解温度为475℃,1 000℃残炭率为21%,耐热性明显优于普通酚醛树脂。 相似文献
8.
9.
《粘接》2008,29(5):38
黑龙江省石油化学研究院采用复合型催化剂合成了一种新型高耐热酚醛树脂,具有较高的热分解温度,且在500℃以上仍有80%的质量保留。同时,对金属的粘接性能很好,粘接钢的室温剪切强度14.7MPa,而用丁腈橡胶(NBR)和聚乙烯醇缩丁醛(PVB)增韧后性能更佳,剪切强度分别为22.4MPa和20.5MPa。当温度大于250℃时,加入增韧剂的粘接强度会有一定程度降低,但仍比一般的耐高温胶粘接强度高。纯酚醛树脂、NBR增韧和PVB增韧的300℃粘接的剪切强度分别为11.2MPa、8.4MPa、7.9MPa;400℃时分别为5.8MPa、5.1MPa、4.3MPa。由于丁腈橡胶具有较大的活性,能与酚醛树脂发生一定程度的交联,使其增韧效果好于聚乙烯醇缩丁醛。 相似文献
10.
11.
《Journal of Adhesion Science and Technology》2013,27(13):1483-1495
Three phenolic resins were used to study the effect of resin structure and its percentage content on the bonding properties of nitrile rubber-based adhesives. The phenolic resins studied are derived from phenol, resorcinol and para-t-butyl phenol, and are of novalac type. These resins were characterized by infra-red and thermal studies. Several formulations were prepared by varying the phenolic resin/nitrile rubber ratio and these formulations were tested for viscosity and bonding properties. At a given resin-to-rubber ratio, the viscosity for resorcinol-formaldehyde resin was higher than phenol-formaldehyde resin followed by para-t-butyl phenol-formaldehyde resin. The peel strength of nitrile rubber-based adhesive prepared from resorcinol-formaldehyde resin was higher than adhesives that from para-t-butyl phenol-formaldehyde resin followed by phenol-formaldehyde resin. The lap shear strength of nitrile rubber-based adhesive containing para-t-butyl phenol-formaldehyde resin was higher than of adhesives containing the other two resins. The trend observed in peel strength could be explained on the basis of hydrogen bonding between hydroxyl groups of phenolic resin (adhesive) and hydroxyl groups of the starch-coated canvas cloth (adherend), whereas the trend observed in lap shear strength could be explained on the basis of extent of linearity in the resin structure. 相似文献
12.
研究了硫化体系和粘合体系对金属-橡胶粘合性能的影响.结果表明,新型的粘合体系可使橡胶的硫化和粘合两过程协同进行,并在橡胶与金属界面间形成强韧性的树脂网络结构,从而获得良好的粘合效果. 相似文献
13.
14.
15.
16.
E. A. Fitzgerald S. P. Tadros R. F. Almeida G. A. Sienko K. Honda T. Sarubbi 《应用聚合物科学杂志》1992,45(2):363-370
Cresol–formaldehyde resins are important components of photoresists for semiconductor fabrication. The type of methylene bridge and relative amounts thereof are key structural features that determine resin properties. Several model compounds were prepared that represent the various types of methylene bridges that are possible from condensation of meta- and para-cresol with formaldehyde. The methylene bridges were characterized by 13C-NMR spectroscopy, and the assignments made were used to analyze spectra of cresol–formaldehyde novolak resin and several oligomer types. The effect of complexation with metal ion on the methylene bridge chemical shift was investigated for one oligomer. The effect of bridging position on the intramolecular hydrogen bonding of the phenolic hydroxyl group was investigated by infrared spectroscopy. 相似文献
17.
18.
Peng Li Yan Song Zhihong Tang Guangzhi Yang Quangui Guo Lang Liu Junhe Yang 《Ceramics International》2013
Ordered mesoporous carbons doped with MnO nanoparticles (DCs) have been prepared by direct carbonization of a composite of a reverse copolymer-low-molecular-weight phenolic resin dipped in aqueous Mn(NO3)2 solution. The microstructure of the DCs was analyzed by the small-angle X-ray scattering, X-ray diffraction, nitrogen adsorption isotherms and transmission electron microscopy. The results showed that the size of MnO nanoparticles dispersed on the surface of DCs was about 10–50 nm and the pore size of DCs could be tailored from 4.9 to 9.3 nm as the amount of phenolic resin varied. Moreover, the structure of the DCs obtained was stripe-like at low amount of phenolic resin. However, the structure of the DCs becomes disordered as the amount of phenolic resin increases. Because of its nontoxic nature and cost-effective synthesis, these DCs exhibit properties that are needed for an environment-friendly catalyst and electrode materials. 相似文献
19.
对苯酚进行分子设计,使对苯二甲基二甲醚(PXDM)与苯酚在碱性催化剂的作用下发生醚交换反应,生成一种对苯二苯基二甲醚结构,再将其与多聚甲醛在碱性条件下反应制备改性酚醛树脂。采用核磁共振波谱仪,红外光谱仪对改性酚醛树脂的结构进行了表征,并研究了改性剂PXDM的引入对改性酚醛树脂耐热性能的影响。结果表明:成功合成了改性酚醛树脂,且其质量损失5%时的温度及负荷变形温度较普通酚醛树脂分别提高了97.8,46.4℃;经过热老化后,改性酚醛树脂的力学性能损失明显小于普通酚醛树脂,说明改性酚醛树脂具有更优异的耐热性能和良好的热稳定性。 相似文献
20.
对酚醛树脂在轮胎中的应用进行了回顾和展望。在轮胎生产中,酚醛树脂是重要的原材料之一。酚醛树脂具有优异的物理性能以及丰富的反应官能团,在轮胎生产过程中可起到增粘、补强、粘合以及交联等作用。随着轮胎生产技术和材料研发水平的不断提高,酚醛树脂生产企业应顺应时代潮流,不断开发性能更优异、更环保的产品,以满足高性能轮胎生产要求。 相似文献