环化聚丁二烯的合成及其在光刻胶中的应用

本文扼要地阐述了国内外环化橡胶的研究发展状况，介绍了环化天然橡胶、环化聚异戊二烯橡胶和环化聚丁二烯橡胶的合成新方法及其结构表征技术。其中，重点介绍了环化聚丁二烯橡胶的合成新技术。由于环化橡胶负性光刻胶对金属及硅片的粘接性和耐酸性方面的优异性能以及其良好的热稳定性能，因此被广泛应用于硅、二氧化硅及铬不锈钢等材料的光刻，因而在高密度集成电路的生产与研制上得到了广泛应用。同时，本文还介绍了市场上常见的几种环化橡胶光刻胶产品。     

几种环化橡胶的制备

综述了几种环化橡胶的制备方法,讨论了阳离子环化机理引起的制备方法的差异。     

环化橡胶

天然橡胶在100～150℃加热条件下与环化剂(可以是硫酸、硝酸、磷酸、氯磺酸、苯磺酸中的任何一种)一起反应,经过几小时到几十小时的作用,经历了异构化过程,得到的环状结构产物即被称为环化橡胶。根据环化程度深浅的不同,它的软硬程度也不等,可以是非弹性的,甚至是热塑性的。尽管如此,它们化学式都是C5H8,与天然橡胶相同。不同点在于长链结构中的双键大幅度减少,不饱和度降低。     

稀土催化合成反式,环化和顺反立构嵌段聚异戊二烯

采用新型稀土催化体系Ｌ３－ｎＬｎＸｎ－Ｒ３Ａｌ－ＲＸ，研究了催化体系各组分、室温下再陈沦时间、ＲＸ和Ｒ３Ａ种类及用量、溶剂种类等因素对异戊二烯聚合的影响。在此基础上，经经环化聚合合成出环化聚异戊二烯，并尝试了异戊二 立构癌段聚合，用Ｉ动态力学测试等方法表片了聚合物的结构，合成出含１，４－结构６８．１％含环化结构的２８．９％，顺－１，４和反－１，４链段的Ｔｇ分别为－２９℃和７０℃的顺反立嵌段聚异戊二     

异苯橡胶环化反应动力学研究及产物微细结构表征

本文采用红外光谱法研究了前无报导的聚异苯橡胶环化反应动力学，测定了标题反应的动力学参数：反应级数ｎ＝１；活化能Ｅ＿ａ＝５３．２ｋＪ·ｍｏｌ￣（－１）；指前因子Ａ＝２．２４×１０￣６ｍｉｎ￣（－１），确立了该反应速率常数ｋ＿ｔ与ｓ反应温度Ｔ之间的函数关系为：Ｌｎ（ｋ＿Ｔ／ｍｉｎ￣（－１））＝１４．６２—６．４０×１０￣３Ｋ／Ｔ并采用核磁共振法分析了标题反应的产物环化异苯橡胶的微细结构，提出了标题反应的可能机理，并对活化能及指前因子进行了分析讨论。     

环化橡胶共混物的热学性能和热力学参数

上世纪50年代以来,橡胶科学界一直在关注由天然橡胶（NR）、聚丁二烯橡胶（BR）和异戊二烯橡胶（IR）产生的环化橡胶。环化橡胶产品使用在粘合剂、涂料、油墨的配方中,也用于NR的配合来改善其力学性能,环化NR可加入到胎面胶胶料中来改善牵引性能、胎面耐磨性和耐撕裂性。更进一步的是,以这一发现为基础,环化IR可以与氯化丁基橡胶或NR共混,用于轮胎气密层胶料。     

异苯橡胶环化反应动力学研究圾产物微细结构表征

本采用红外光谱法研究了前无报导的聚异苯橡胶环化反应动力学，测定了标题反应的动力学参数：反应级数ｎ＝１；活化能Ｅａ＝５３．２ｋｊ·ｍｏｌ＾－１；指前因子Ａ＝２．２４×１０＾６ｍｉｎ＾－１，确立了该反应速率常数ｋｔ与ｓ反应温度Ｔ之间的函数关系为：Ｌｎ（ｋＴ／ｍｉｎ＾－１）＝１４．６２－６．４０×１０＾３Ｋ／Ｔ并采用核磁共振法分析了标题反应的产物环化异苯橡胶的微细结构，提出了标题反应的可能机理，并对活     

环化氯丁橡胶的表征

在氯丁橡胶中加入环化试剂AlEt2 Cl-C6H5CH2 Cl,在 12 0℃× 2 0min条件下 ,可制备环化氯丁橡胶。借助IR ,1H -NMR ,DSC ,GPC和裂解色谱测试方法对产物进行了表征。结果表明 ,二甲苯溶剂参与了环化反应 ,且随环化度增加 ,参与反应的溶剂二甲苯的数目也逐渐增加 ,并确定了环结构的形成     

环化丁苯橡胶的表征

在ＳＢＲ中加入环化试剂ＡｌＥｔ２Ｃｌ－Ｃ６Ｈ５ＣＨ２Ｃｌ,在１２０℃,２０ｍｉｎ条件下制备了环化ＳＢＲ,并借助ＩＲ,＾１Ｈ－ＮＭＲ,ＤＳＣ,ＧＰＣ等方法对产物性能进行了表征。结果表明,二国本溶剂参与了环化反应,且随环化度增加,参与反应的二甲苯量也逐渐增加,并确定了环结构的形成。利用＾１Ｈ－ＮＭＲ谱图导出了环化ＳＢＲ的环化度和溶剂参与量的计算公式。     

在AlEtCl2—CH2—CH—CH2Cl体系作用下顺—1,4聚丁二烯的环化研究

本文以AIEtCl_2—CH_2=CH—CH_2Cl体系进行了镍系顺-1,4聚丁二烯的环化研究。讨论了催化剂组成、配比、母胶浓度等对环化反应的影响。对产物性能、结构进行了初步表征。     

Synthesis and properties of photosensitive rubbers. I. Direct addition reaction of α,β-unsaturated carboxylic acids to polydienes and polypentenamer

The addition reaction of α,β-unsaturated carboxylic acids to polydienes, such as cis-1,4-polybutadiene, 1,2-polybutadiene, and polypentenamer, was investigated in the presence of acid catalysts in order to obtain photosensitive rubbers. The structures of products obtained were identified as cyclized polydiene rubbers having pendent α,β-unsaturated carboxylate groups. The amount of the incorporated substrates increased up to the maximum of around 20 mole %, and the amount of the residual unsaturated groups in the polymer backbone decreased because of cyclization of the double bond. The products had two glass transition temperatures. These glass transition temperatures were identified as follows: a lower transition, owing to the original polydiene segment where the incorporated carboxylate groups were located; and a higher one, owing to cyclic segment. These two thermal transitions on the polymer backbone indicate that the cyclic structure exists as a block segment in the polymer and the carboxylate group is incorporated at random in a polydiene structure. The synthetic condition needed to obtain a desired amount of the incorporated substrate and the degree of the cyclization of polydienes and polypentenamer were investigated.     

Dynamic mechanial properties of sulfonated cyclized cis-1,4-polyisoprene

Acetyl sulfate was used as sulfonating agent for the sulfonation of cis-1,4-polyisoprene. IR and NMR spectra showed that the sulfonation was accompanied by extensive cyclization. A series of DSC and loss tangent studies of both the sodium salts and the methyl esters was undertaken. It was found that cyclization exerts a profound influence on the micrbrownian segmental motion of the hydrocarbon matrix and is the dominant factor in raising the glass transition temperatures. However, the differences in the mechanical properties between salts and esters suggest that the presence of ions does influence the melt viscosities and shear moduli of the sulfonated cyclized rubbers; this influence can be minimized by esterification or water absorption. It is seen that the ionic effects in these materials are quite typical of those encountered in a wide range of other ionomers.     

Graft copolymers from peroxidized EPDM rubber

The transition metal catalyzed peroxidation of the pendant allylic functionality in EPDM rubbers with tertiary butyl hydroperoxide results in elastomeric, high polymer peroxides. The peroxidized EPDM rubbers are useful as free radical initiators for the polymerization and grafting of vinyl monomers in the preparation of comb-type structures. The grafted EPDM rubbers are efficient impact modifiers for thermoplastic resins so long as the polymer grafted onto the EPDM is identical to or is thermodynamically miscible with the composition of said thermoplastic resin.     

Crosslinking of poly(ethylene glycol) with divalent metal salts of mono(hydroxyethyl) phthalate,anhydride, and bisepoxide

Poly(ethylene glycol)s (PEG) were crosslinked with divalent metal salts of mono(hydroxyethyl) phthalate, anhydride, and bisepoxide to give metal-containing cured rubbers. As the anhydride, hexahydrophthalic anhydride was used, and bisphenol A diglycidyl ether was the bisepoxide used. As for the physical properties of the cured rubbers obtained, the rubbers containing Mg showed much better physical properties than those containing Ca. In addition, the rubbers with high hard block contents and high overall crosslinking densities exhibited high tensile strength and Shore A hardness, and so did the rubbers having a high degree of crystallinity of the PEG soft block. The occurrence of crystallization became easy as the soft block length became longer and the soft block content became higher, or as the crosslinking density of the hard block became lower. The PEG-based rubbers showed much higher water absorption than the previously reported poly(propylene glycol)-based rubbers, due to the much higher hydrophilicity of the PEG block. Resistance to chemical attack and stress–relaxation are also discussed.     

Ionic crosslinking of carboxyl-terminated liquid rubbers with metal oxides

Ionic crosslinking of carboxyl-terminated liquid rubbers with metal oxides and metal carbonates, mainly with the former, were investigated. The liquid rubbers used were a polymer of butadiene (Hycar CTB 2000X162) and a copolymer of butadiene–acrylonitrile (Hycar CTBN 1300X8). The CTBN ionically crosslinked rubbers obtained showed higher tensile strength than the CTB series, due to the polarity effect of the nitrile groups. The ionic rubbers cured with MgO and CaO were studied in detail, and it was found that their tensile strength increased markedly with increase in the metal oxides used, and in addition white carbon and carbon black showed remarkable reinforcing effects. The properties such as tensile strength, elongation, Shore A hardness, and melt index are influenced by humidity. It is characteristic of these ionically crosslinked rubbers that they can be successfully reprocessed.     

Fumaric Acid as a Promoter of Adhesion in Vulcanized Synthetic Rubbers

The addition of dicarboxylic acids to polyurethane adhesives, to improve their adhesion to vulcanized synthetic rubbers, may cause the degradation over time of the adhesives. To avoid the degradation of polyurethane adhesives, this study proposes a surface treatment on vulcanized synthetic rubbers with carboxylic acid solutions instead of adding them to the adhesives. In all the styrene-butadiene rubbers studied, a great improvement in adhesion to polyurethane adhesives has been obtained. The nature of the solvent used to disperse the fumaric acid over the surface, as well as the nature of the rubber, determined the effectiveness of the surface treatment. The use of fumaric acid solutions provided optimum results when the surface of the rubber was slightly roughened. The increase in the adhesion properties of styrene-butadiene rubbers, treated with fumaric acid, has been attributed to an increase in the degree of the surface roughness and to an enhancement in the surface energy (due to the elimination of abhesive substances on the surface of the rubber and to the formation of C-O groups by surface oxidation). The effectiveness of the surface treatment on rubbers with fumaric acid in the adhesion of styrene-butadiene rubbers has been compared with those produced by other common treatments, such as halogenation and roughening. In general, T-peel strengths obtained in the rubbers treated with fumaric acid were similar to those obtained through halogenation and were always higher than those obtained through roughening. Therefore, surface treatment of styrene-butadiene rubbers with fumaric acid can be considered as an alternative method to chemical treatments currently used, especially in the footwear industry.     

填充型导热橡胶研究进展

介绍了导热橡胶的研究现状,综述了导热绝缘与导热非绝缘橡胶导热性能及导热模型的研究进展,重点讨论了金属氧化物、碳化物、氮化物、金属粉、炭黑及各类碳材料填充导热橡胶的研究进展。     

Toughening bismaleimide resins by reactive liquid rubbers

The modification of bismaleimide resins with carboxyl-terminated butadiene–acrylonitrile rubbers (CTBN) was studied. The effects of the rubbers on mechanical and thermal properties such as flexural strength, tensile strength, fracture toughness, glass transition temperature, and decomposition temperature of the rubber-modified bismaleimide resins are discussed. The morphology of these resins were investigated by means of scanning electron microscopy and dynamic mechanical analysis. Addition of the rubbers improved the toughness of the bismaleimide resins without significant reductions in heat resistance of the resins.