合成三酚基甲烷三缩水甘油醚工艺研究

三酚基甲烷三缩水甘油醚是一种耐高温环氧树脂,具有良好的韧性和加工性能。这种树脂广泛用于高性能复合材料、封装材料等领域。主要研究以苯酚和对羟基苯甲醛为原料合成三酚基甲烷,再以三酚基甲烷与环氧氯丙烷(ECH)缩合制备三酚基甲烷三缩水甘油醚。通过不同反应条件的对比,得出制备优质三酚基甲烷三缩水甘油醚的最佳工艺条件。     

环氧树脂电子束辐射固化研究进展

电子束(EB)固化技术是1种热固性树脂固化成型新方法。与传统固化方法相比,具有高效,低成本,环保等优点。对环氧树脂电子束固化的特点、反应机理以及应用前景进行了综述。     

三溴代苯基缩水甘油醚的合成

本文报导了一种新型活性阻燃剂─三溴代苯基缩水甘油醚的合成及其应用。     

电子束固化机理

主要从下述几方面介绍了电子束固化机理：电子束和紫外光固经机理比较;电子束与介质相互作用过程;电子束固化过程中起作用的活性粒子;电子束固化丙烯酸酯体系和阳离子体系的机理等。     

不同化学结构环氧树脂电子束固化效果的分析

研究了化学结构对环氧树脂电子束辐射反应速率和辐射固化效果的影响。对于分子量相近的环氧树脂，反应速率大的环氧树脂体系最终达到的反应程度较高。酚醛型环氧树脂辐射反应活性高，固化后的高温模量及玻璃化转变温度高于双酚A型环氧树脂，但固化度沿辐射深度方向下降较快，脂环族环氧树脂的辐射反应活性小，在相同辐射条件下的固化效果差。缩水甘油胺结构的环氧树脂对于碘Wong盐引发的电子束辐射固化反应没有活性。     

多环氧基腰果酚缩水甘油醚改性环氧树脂粘接性能研究

采用间氯过氧苯甲酸(MCPBA)对腰果酚缩水甘油醚(CGE)侧链上的双键进行环氧化,制备了多环氧基腰果酚缩水甘油醚(PECGE)。研究了以三乙烯四胺为固化剂的PECGE改性双酚A型环氧树脂E-51胶粘剂的固化性能、粘接性能和热稳定性。结果表明:PECGE的改性,可延长环氧树脂胶粘剂的适用期、凝胶时间、硬化时间,并提高了室温固化度;PECGE的加入量为10份时,室温固化5d后室温和80℃的拉伸剪切强度分别提高了29.8%和79.4%,加热固化后室温和80℃的拉伸剪切强度分别提高了6.7%和17.1%;对应失重5%的温度值下降了8.5℃。     

邻氯对苯二酚二缩水甘油醚合成及其固化体系研究

以邻氯对苯二酚、环氧氯丙烷为原料,四乙基溴化铵为相转移剂,在碱性条件下,合成邻氯对苯二酚二缩水甘油醚。最佳合成条件:n(环氧氯丙烷)∶n(邻氯对苯二酚)为18,x(催化剂)为1.0%,闭环反应4 h最高收率可达80.5%。通过傅里叶红外光谱仪和显微熔点测定仪对产物结构和熔点进行了表征,并计算出该产物与甲基四氢苯酐(Me–THPA)的固化体系的活化能。     

丙氧基化双酚A缩水甘油醚的合成与固化性能

以丙氧基化双酚A（D33）、环氧氯丙烷（ECH）和液碱为主要原料,采用两步法工艺合成了丙氧基化双酚A缩水甘油醚（DGEPBA）。考察了原料配比、催化剂用量、反应温度、反应时间等因素对反应的影响。结果表明：开环催化剂三氟化硼-乙醚（BF₃-Et₂O）,质量分数0.1%,D33与ECH的质量比为1∶2.0,反应温度70℃,反应时间2.5h;闭环催化剂苄基三乙基氯化铵质量分数0.2%,D33与NaOH的质量比为1∶2.2,反应温度40℃,反应时间6h时,产物环氧值为0.291eq/100g,产率95.4%,黏度为1180mPa·s。通过FTIR和¹H NMR对产物结构进行表征,并将不同质量分数的DEEBAPO掺入到E-51环氧树脂中,与二乙烯三胺（DETA）进行固化,并对其固化物力学性能进行测试。因为DGEPBA的掺入,使得E-51固化物在抗拉伸、抗冲击方面均有明显提高。热失重（TGA）分析表明固化物热稳定性稍有提高,扫描电镜（SEM）显示断裂面为韧性断裂。     

双酚A二缩水甘油醚的合成研究

论述了双酚Ａ二缩水甘油醚的合成方法和较佳反应条件。     

电子束固化复合材料技术

简述了电子束（EB）固化复合材料的特点,介绍电子束固化机理,电子束固化树脂基体性能,复合材料试件及发动机壳体性能及电子束固化技术在航空航天复合材料其他领域的应用前景。     

采用模型化合物研究环氧树脂电子束固化机理

通过红外光谱、凝胶渗透色谱及核磁共振分析研究了单官能模型化合物苯酚缩水甘油醚在不同辐射剂量、引发剂浓度和羟基化合物掺杂情况下的电子束固化反应特性及机理。结果表明,环氧基团反应完全后,大幅度增加辐射剂量不会导致已经聚合的环氧树脂出现明显的辐射降解,但是引发剂浓度的增加和羟基化合物乙醇使聚合环氧树脂的分子质量下降。     

Coating characteristics of electron beam cured bisphenol A diglycidyl ether diacrylate resin containing 1,6-hexanediol diacrylate on wood surface

Electron beam curing of bisphenol A diglycidyl ether diacrylate resin (BDGDA) mixed with varying amount of 1,6-hexanediol diacrylate monomer (HDDA) was investigated using low energy DC electron beam accelerator. Cured coating films were analyzed by Fourier transformed infrared spectroscopy (FTIR), gel fraction, swelling ratio and thermogravimetric (TG) techniques. The wood surfaces cured with different coating compositions were tested for their end use performance properties like gloss, pencil hardness, scratch resistance, mar resistance, abrasion resistance, chemical resistance, steam resistance and cigarette burn resistance. FTIR studies indicated that the density of acrylate functionality and degree of curing increased with the HDDA content in the feed mixture. This observation was supported by gel fraction and swelling studies as well. The thermal stability, pencil hardness, mar resistance, abrasion resistance and solvent resistance properties of coating were observed to improve with the incorporation of HDDA. However, there was significant decrease in gloss and scratch resistance at higher HDDA content. The coating showed excellent steam and stain resistance but poor resistance to cigarette burns.     

Exothermic effect in the process of electron‐beam curing of epoxy resins

Temperature measurements have been performed in the process of electron‐beam curing of EB‐I and EB‐II epoxy resin systems. The influence of initiator content, resin type, and dose rate on the temperature of the systems was studied. Transverse and longitudinal temperatures of samples in the glass vessel were also analyzed. The nature of temperature curves varied with the different epoxy resin systems in the steel mold, but did not change with different contents of the initiator. At the same time, the heat had no effect on the gel fraction of epoxy resin systems. The temperature curve was greatly affected by the dose rate, and its peak value, peak width, and plateau value also increased with it. The transverse temperature of EB‐II glass vessel samples increased as the radiation dose increased and, in the same sample, the temperature reduced as the distance between the radiation center and the test point increased. The longitudinal temperature of EB‐I and EB‐II resin systems in a glass vessel decreased as the radiation depth increased. As the radiation dose increased, the temperature of the EB‐I resin system increased simultaneously, while that of the EB‐II resin system initially increased and then kept constant when the dose reached a certain value. The temperatures of these two resin systems decreased rapidly when the radiation process stopped. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2217–2222, 2004     

Microporous polyurethane-acrylamide film cured by electron beam irradiation

The morphology and aggregation structure of electron beam (EB)-cured microporous polyurethane-acrylamide film was investigated. The urethane-acrylamide prepolymer was synthesized by the reaction of poly(butylene adipate)diol, 4,4′-diphenylmethane diisocyanate, and N-(hydroxymethyl)acrylamide. It was found from scanning electron microscopy that the urethane-acrylamide film, which was prepared by using a methyl ethyl ketone and dimethylformamide (3:1 v/v) mixture as casting solvent, had a microporous structure with pore size of several micrometres, and that the morphology was fixed by EB irradiation. The pore volume of the EB-cured microporous film was determined to be about 460 mm³ g⁻¹ by mercury porosimetry. The micropores were not destroyed even after immersing in solvent, possibly because the cured film had high crystallinity and dense crosslinking. Moreover, it was found by X-ray photoelectron spectroscopy that terminal portions of urethane-acrylamide were localized at the film surface.     

Pulsed electron beam irradiation of dilute aqueous poly(vinyl methyl ether) solutions

A dilute aqueous solution of the temperature-sensitive polymer, poly(vinyl methyl ether) (PVME), was irradiated by a pulsed electron beam in a closed-loop system. At temperatures, below the lower critical solution temperature (LCST), intramolecular crosslinked macromolecules, nanogels, were formed. With increasing radiation dose D the molecular weights M_w increase, whereas the dimensions (radius of gyration R_g, hydrodynamic radius R_h) of the formed nanogels decrease. The structure of the PVME nanogels was analyzed by field emission scanning electron microscopy (FESEM) and globular structures with d=(10-30) nm were observed. The phase-transition temperature of the nanogels, as determined by cloud point measurements, decreases from T_cr=36 °C (non-irradiated polymer) to T_cr=29 °C (c_p=12.5 mM, D=15 kGy), because of the formation of additional crosslinks and an increase in molecular weights. The same behavior was observed for a pre-irradiated PVME (γ-irradiation) with higher molecular weight due to intermolecular crosslinks. After pulsed electron beam irradiation the molecular weight again slightly increases whereas the dimension decreases. Above D=1 kGy the calculated ρ-parameter (ρ=R_g/R_h) is in the range of ρ=0.5-0.6 that corresponds to freely draining globular structures.     

均苯四甲酸二酐固化环氧树脂的工艺及热性能

将均苯四甲酸二酐与环氧树脂溶于丙酮中,在一定的温度条件下反应,制备了均一的、有一定固化程度的环氧树脂溶液,该溶液可在常温固化。傅里叶变换红外光谱分析表明,所得产物与预期结构相同,最佳反应时间为6 h。采用差示扫描量热法研究其固化工艺,不同升温速率下,体系的固化温度不同,随升温速率增加,固化温度提升,通过动力学计算得到其固化工艺为100℃固化2 h,150℃固化2 h,后处理180℃固化2 h,按此工艺固化的环氧树脂的耐热性能优于常温固化,起始分解温度达到368℃。     

电子束固化水性聚氨酯丙烯酸酯的制备及性能

研究了一种制备水性聚氨酯丙烯酸酯的新方法,通过在扩链剂分子结构中组装离子基团来改善亲水性,解决了聚氨酯丙烯酸酯与水难相溶的问题。采用这种方法制备了一种聚氨酯丙烯酸酯产物,使用FTIR和1H NMR对产物结构进行了表征。对产物与水的储存稳定性、黏度、电子束固化行为及固化后性能进行了研究。结果表明,分散乳液储存稳定性好,经电子束固化后性能(如硬度、附着力、光泽度、柔韧性、热稳定性)优良。     

Poly(4-methylstyrene-co-chloromethylstyrene): A negative electron beam resist—synthesis and lithography evaluation

Synthesis and lithographic characterization of a series of negative acting electron sensitive resists based on poly(4-methylstyrene-co-chloromethylstyrene) are reported. The sensitivity and contrast of these resists were found to depend on the chloromethylstyrene (CMS) content and an optimum value of 5 wt% was determined from consideration of parameters associated with the reproducibility of the synthetic method and also the lithographic performance. Both the sensitivity and resolution were found to depend on the molecular weight and CMS content of the copolymer. Several methods of scale up for the synthesis were explored, the route having a very significant influence on the film formation characteristics of the resists. The reactivity ratios of the monomers were measured in order that the compositional drift, which occurs during the synthesis, could be quantified. The effect of solvent composition and molecular weight of the copolymer were explored in relation to the quality of the resulting lithography. These studies have indicated that the copolymer has the potential of being used as a VLSI sub-micron resist with good plasma etch resistance.     

室温固化低黏度双酚F环氧树脂体系的研究

选择具有设计结构的固化剂和活性稀释剂,并研究其对体系性能的影响,确定了室温固化耐高温低黏度双酚F环氧树脂配方体系。该体系黏度低,凝胶时间较长,耐热性良好,力学性能优异。固化产物的T_g可达110℃以上,拉伸强度可达90 MPa,弯曲强度可达150 MPa。能够很好地适用于低温固化,中、高温使用的树脂基复合材料成型技术。