粉末橡胶和液体橡胶的加工工艺

本文主要介绍了粉末橡胶的液体橡胶的加工工艺、设备及其用该项技术覆盖的制品所具有的特性，并对新技术的设备能耗和生产效率等进行了比较。     

国际橡胶工业兴衰的启示

一部世界橡胶工业的发展史,实际上也是橡胶技术进步和科学管理的演变记录。现有资料中最早记载橡胶存在于地球上的是1496年哥伦布(Christropher Columbus)第二次到新大陆时,在南美洲发现了天然橡胶树,当地人称之谓“卡乌丘”CAU-UCHU,意思是“流泪树”。当时由于最基本的加工技术尚未为人类掌握,只能任其自生自灭。直到1839年固特异(Charles Goodyear)发明了橡胶的“硫化”技术之后,才使这宝贵的天然材料开始有了实用价值,从而陆续设厂加工生产。然而真正形成一门引人注目的橡胶工业,还是在本世纪初。时至今日,橡胶工业已是现代化国家必不可少的经济组成部门,无论国防民用、太空     

氯化橡胶随笔

近阅涂料杂志,偶有所感,随笔探讨,以供交流。 日文杂志“涂装涂料”(1994年8月P80)中载有日本的“中国涂料株式会社”的商品介绍,其中有: SC无四氯化碳的氯化橡胶涂料 它不含四氯化碳,不会破坏臭氧层,符合国际Montreal议定书,施工性和漆膜性质与以往的氯化像胶涂料不变,可用于海运集装箱的防腐蚀和装饰。     

耐低温橡胶的研究进展

综述了耐低温橡胶的研究进展,主要对氟橡胶、硅橡胶、丁腈橡胶、丙烯酸酯橡胶和聚氨酯橡胶的耐寒性性能及其改良方法进行了介绍,总结了目前提高橡胶耐低温性能的主要途径及对未来的发展方向提出一些看法,为制备耐低温橡胶提供参考。     

New thermosetting coatings using blocked carboxyl groups

Characteristics of blocked carboxylic acid compounds obtained by blocking carboxyl groups with alkyl vinyl ethers were studied, and new thermosetting coatings using blocked carboxyl groups and epoxide were also studied. Polybasic carboxylic acids were esterified with alkyl vinyl ethers to obtain blocked carboxylic acids having the hemiacetal ester moieties. Most of blocked carboxylic acids obtained were liquids and showed an excellent solubility in organic solvents and a good compatibility with epoxy resins. Although the blocked carboxylic acids were stable under ambient conditions, they could regenerate the corresponding carboxylic acids accompanied by the elimination of alkyl vinyl ethers by the thermal dissociation. They could be used as noble thermal latent hardeners. Curing of the blocked carboxyl groups and epoxide in the presence of relatively weak Lewis acid proceeded through a sequence of three-step reactions consisting of deblocking of alkyl vinyl ethers, esterification of epoxide, and the addition of alkyl vinyl ether to 2-hydroxyalkyl ester. The main product of the curing system was 2-acetalalkyl ester, but not 2-hydroxylalkyl ester. The new one-package thermosetting coatings using blocked carboxyl groups have been evaluated for use in the practical automotive and coil coatings line production. VOCs reduction, low-toxicity, and cost saving are satisfactory for the application of the systems. And the cured films of the coatings offered advantages in the high durability, the acid resistance and the soil resistance.     

高性能水性聚氨酯涂料的研制

针对水性聚氨酯涂料普遍存在耐水、耐溶剂性能差、固化涂膜硬度低等缺点,通过在水性聚氨酯涂料的制备过程中引入半干性油、单体及乙烯基三乙氧基硅烷改善其性能。在半干性油的氧化交联与乙烯基三乙氧基硅烷自交联的共同作用下,涂膜的交联密度变大,性能明显提升。     

Synthesis and applications of cyclic carbonate functional polymers in thermosetting coatings

Thermosetting coatings based on the cyclic carbonate–amine reaction are attractive since polyurethane coatings can be made without the use of isocyanates. Cyclic carbonate functional polymers were prepared via the free radical solution copolymerization of vinyl ethylene carbonate with vinyl ester monomers. The level of vinyl ethylene carbonate was varied from 10 to 50%. In order to develop an understanding of the kinetics of the reaction of cyclic carbonates with amines, kinetics of a number of amines were determined with a model cyclic carbonate, propylene carbonate. The kinetic information was used to help select appropriate amine crosslinkers and develop thermosetting coatings using cyclic carbonate functional polymers and oligomers. For screening of coating properties, clear coating formulations were applied to pretreated metal panels and cured at 80°C for 45 min. A number of coatings were prepared to study the effect of amine, stoichiometry, solvent, and copolymer composition on the coatings properties. Coatings prepared had excellent solvent resistance, good gloss, and high pendulum hardness.     

New vinyl ester monomers for emulsion polymers

New vinyl ester monomers are now available for the preparation of emulsion copolymers with improved hydrolytic stability and water resistance. These improved properties are the result of uniform copolymerization of hydrophobic monomers having approximately the same reactivity as vinyl acetate. Latex coatings with excellent gloss, water spot resistance, blocking and other desirable performance properties can now be obtained with vinyl acetate copolymers.     

Thermoset–thermoplastic hybrid nanoparticles and composite coatings

Structured thermoset–thermoplastic hybrid nanoparticles and composite coatings were successfully synthesized through a novel one-pot approach. Both the polyaddition of epoxy curing and the free radical polymerization of various vinyl monomers were performed in sequence in miniemulsion droplets. Benefiting from the precise control of the compatibility between thermoset phase (epoxy monomer/amine curing agent) and vinyl phase (vinyl monomers/polymers), colloidally stable, core–shell structured thermoset–thermoplastic hybrid nanoparticles between 100 and 200 nm were obtained through chemically induced phase separation. The influence of the compositions on the colloidal stability and morphology of the final hybrid latexes and films was studied in detail. Meanwhile, the mechanical properties of thermoset–thermoplastic coatings and corresponding thermoplastic coatings were investigated. It is found that the thermoset–thermoplastic composite coatings showed significantly improved film properties in terms of hardness compared to the analogous thermoplastic coatings. Furthermore the thermoset–thermoplastic hybrid films were highly transparent even with 33 wt% of epoxy thermoset domains embedded.     

丁烯酸乙烯酯的提取及聚合应用

丁烯酸乙烯酯存在于醋酸乙烯酯生产的工业废液中,可用蒸馏法提取及纯化,具有一些独特的性质:如在一定条件下会聚合形成环状结构;用于以聚醋酸乙烯酯为基础的乳胶漆交联改性时,无须引发剂和加热,只是简单混合即可使耐洗刷次数增加几倍,还可与其它乙烯基酯、氯乙烯、苯乙烯、马来酸酐等多种单体共聚,主要起提供交联的作用.     

Hydrophobic coatings from emulsion polymers

One of the chief requirements of protective coatings is the ability to confer water resistance to painted substrates. To accomplish this task, the coating itself must be water resistant but should also possess the additional performance properties expected of modern coatings. Branched vinyl esters provide the building blocks for preparing very hydrophobic binders by emulsion polymerization. Not only do these monomers have favorable reactivity with vinyl acetate but they also react effectively with acrylates and can be formulated into a wide range of performance coatings. Hydrophobic polymers find use in a wide range of applications including architectural paints, building products and corrosion resistant coatings. In addition to the design of reliable measurements of water resistance, it would be beneficial to be able to predict the water sensitivity of materials based on composition. Calculations of oxygen contents and solubility parameters of polymers are proposed as useful approaches to estimating the hydrophilicity of coatings in order to define the hydrophilic limit imposed on coatings by various water resistance tests. Presented at the 78th Annual Meeting of the Federation of Societies for Coatings Technology, on October 18, 2000, in Chicago, IL. 410 Gregson Dr., Cary, NC 27511.     

巴豆酸乙烯酯的提取及聚合应用

巴豆酸乙烯酯存在于醋酸乙烯酯生产的工业废液中,在一定条件下聚合会形成环状结构。用于改性以聚醋酸乙烯酯为基础的乳胶漆无须引发剂和加热,只是简单混和即可使耐洗刷次数增加几倍,还可与其它乙烯基酯、氯乙烯、苯乙烯、马来酸酐等多种单体交联共聚。     

彩色VAE防水涂料的制备

醋酸乙烯－乙烯共聚物（ＶＡＥ）防水涂料具有色彩美观、耐久性好、施工方便、不污染环境等特点，优于其他类型的防水涂料。介绍了ＶＡＥ防水涂料的配方和制备工艺。列举了该涂料的性能指标。讨论了影响涂料性能的诸种因素。     

苯乙烯-叔碳酸乙烯酯-丙烯酸酯共聚微乳液的合成

通过选择合适的乳化体系及合成工艺，制备具有高光泽度、耐磨、耐色变性的苯乙烯-叔碳酸乙烯酯-丙烯酸酯共聚微乳液树脂，应用于印刷无溶剂上光油、高层建筑外墙水性涂料及透明木器涂料等。