新一代耐高温多功能重防腐涂料用树脂——聚芳醚酮的国内外发展历程及现状

聚芳醚酮(PAEK)类树脂属于耐高温、高强度的热塑性工程塑料,作为化工设备重防腐领域中搪玻璃制品的代替品,它已被日本和欧美等国家广为采用。本文从产品开发、应用领域和涂覆工艺等方面论述了PAEK类树脂的发展历程。介绍了国内在PAEK类树脂合成方面所取得的突破:在第一代产品聚醚醚酮(PEEK)的合成中,以新的溶剂环丁砜取代二苯砜,降低了聚合温度,缩短了聚合周期,减少了溶剂消耗,生产效率提高了一倍;在第二代、第三代产品的研发中,立足于国产原料,合成了具有更高耐热等级的PEEKK和PEDEK产品,它们的耐热性比国外产品更好,但成本大幅度下降。     

苯并噁嗪树脂合成、耐热及增韧改性研究进展

介绍了苯并噁嗪(BZ)树脂的合成方法(溶剂法和非溶剂法),特别综述了BZ耐热、增韧改性在单体的分子结构设计、引入其他可聚合官能团、形成共混或共聚物以及加入纳米粒子等方面的研究进展。最后对BZ树脂的发展方向进行了展望。     

高固含量低黏度羟基丙烯酸树脂的制备

分别在采用了单一溶剂二甲苯及二甲苯/正丁醇混合溶剂的两种溶液聚合体系中,以甲基丙烯酸甲酯(MMA)、苯乙烯(St)、丙烯酸丁酯(BA)、丙烯酸(AA)和丙烯酸羟乙酯(HEA)等为聚合单体,偶氮二异丁腈(AIBN)为引发剂,合成了两种高固含量、低黏度的羟基丙烯酸树脂,并采用异佛尔酮二异氰酸酯(IPDI)三聚体分别对这两种羟基丙烯酸树脂进行交联固化。随后对两种羟基丙烯酸树脂的黏度及其固化涂膜的性能分别进行了表征。结果表明:加入正丁醇(作为第二溶剂)可在缩短涂膜的干燥时间,提高涂膜附着力及耐酸碱性能等主要性能指标的同时,显著降低羟基丙烯酸树脂的黏度,使其黏度由1 980 m Pa·s降至850 m Pa·s。通过对聚合反应过程中单体、混合溶剂的比例以及聚合树脂黏度等的调节,成功制备出了固含量高达65%且综合性能较好的羟基丙烯酸树脂。     

生产聚碳酸酯树脂的"清洁"工艺

日本三菱工程塑料公司已开发出一种更符合环保要求的聚碳酸酯 (ＰＣ)树脂生产新工艺 ,并计划于明年建成生产能力为 2 0ｋｔ/ａ的装置。该公司称新工艺避免了传统工艺在双酚Ａ和光气聚合中作为溶剂使用氯代甲烷。新方法在大约 2 0 0℃和 2～ 5ｋＰａ压力下通过酯交换聚合 ,用熔融的碳酸二苯酯和双酚Ａ合成ＰＣ树脂。三菱公司称新工厂的投资大约为 42 0 0万美元。生产聚碳酸酯树脂的“清洁”工艺@郑元昌     

悬浮态乳液聚合制备疏松型聚甲基丙烯酸甲酯树脂

以水为分散相、甲基丙烯酸甲酯(MMA)为连续相进行悬浮态乳液聚合,合成疏松型聚甲基丙烯酸甲酯(PMMA)树脂。研究发现:在聚合体系中加入一定量的PMMA不良溶剂才能制备疏松型PMMA树脂,随不良溶剂环己烷用量和水油比的增大,PMMA树脂的疏松性和邻苯二甲酸二辛酯(DOP)吸收量增加;加入乳化剂使树脂的初级粒子平均粒径变小,而引发剂用量对树脂颗粒内部形态的影响较小。     

乙烯-三氟氯乙烯共聚物粉末氟树脂及涂料的研究

以Freon溶液沉淀聚合体系合成ECTFE (乙烯 -三氟氯乙烯 ,简称F30 )共聚物粉末氟树脂的聚合工艺 ,讨论了聚合反应单体不同配比、不同溶剂配比等对聚合产物性能的影响 ,并检测了涂膜的理化性能     

多元共聚高吸油树脂合成及性能研究

以(甲基)丙烯酸酯类、苯乙烯为主要共聚单体,双甲基丙烯酸乙二醇酯(EGDMA)、二乙烯基苯(DVB)等为交联剂,采用悬浮共聚工艺合成了一系列高吸油树脂.研究了树脂共聚单体组成、丙烯酸单体链长、交联剂种类、交联度、引发剂量以及聚合工艺等因素对吸油树脂吸油量等性能的影响.结果表明:采用EGDMA交联时以丙烯酸十四酯的效果最佳,采用DVB交联时以丙烯酸十二酯效果最佳;交联剂种类及交联度大小对树脂吸油性能及树脂形态有明显影响;树脂交联度的大小明显影响树脂共聚物的转化率与可溶性分率,也明显影响树脂产品的收率.在最佳合成条件下制备的高吸油树脂具有较佳的吸油性能,对甲苯的吸附量可达17.32 g/g树脂.     

水溶性丙烯酸树脂的制备研究

用于水性油墨的水溶性丙烯酸树脂由丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)三种单体采用传统的自由基溶液聚合方式合成,通过大量的对比实验筛选了各种不同的反应条件,获得了最佳合成工艺,包括引发剂、溶剂、加料方式、聚合时间和温度。对影响树脂性能的指标如共聚物组成、玻璃化转变温度Tg等各种因素,采用DSC、IR等分析方法进行了详尽的分析和表证。     

聚丙烯酸钠类高吸水性树脂的研究

采用反相悬浮聚合法合成高吸水性树脂.将丙烯酸(单体,水相)用氢氧化钠部分中和,然后与环己烷(溶剂,油相)共混,用水溶性的过硫酸钾做引发剂,N,N-亚甲基双丙烯酰胺做交联剂,在一定的反应温度和时间下,得到聚丙烯酸钠高吸水性树脂.     

高固体份含羟基丙烯酸树脂合成新方法及其聚氨酯涂料的制备

本文介绍了一种合成分子量相对较高,分子量分布很窄,而且粘度低的高固体份含羟基丙烯酸树脂的新方法,并研究了聚合温度,反应混合物添加速率,引发剂,链转移剂及溶剂的类型与用量等各参数对丙烯酸树脂A和丙烯酸树脂B的结构与性质的影响,A、B两种树脂分别是由单体MMA／St/BA/PGMA与MMA／St/EA/HEMA合成而得。结果表明,单体的物理与化学性质对最终产物树脂的结构与性质有着很大影响：PGMA含有大量α－H,容易在合成中引起支化反应,巯基乙醇不但能在链端引入羟基基因,而且也是获得窄分子量分而树脂的最佳链转移剂,溶剂的结构和组成在合成高固体份,低粘度的丙烯酸树脂中起着重要作用。溶剂油与Cypar－9份别含有异链烷烃和环烷烃,为合成高固体含量丙烯酸树脂的最佳选择,在这两种溶剂中合成的树脂呈半固相分离状,如若最终获得溶液树脂,则聚合温度与溶剂量对树脂结构与性质有很大影响,若最终获得溶涨或半固相分离状树脂,则聚合温度与溶剂量对树脂结构与性质影响不大。以这种方法合成的含羟基丙烯酸树脂,以异氰酸酯作固化剂制备的清漆的性能相当于甚至优于目前市面上流行的Joncryl 920制备的清漆的性能。     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.     

泡沫起泡性、稳定性及评价方法

本文论述了泡沫的两个基本性质:起泡性和稳定性。对起泡性和提高泡沫稳定性的方法作了评价。