端噁唑啉聚醚对环氧树脂的固化与增韧作用的研究

用IR、DSC等分析方法研究了端2-噁唑啉聚环氧丙烷(活性聚醚)与环氧树脂的固化反应,对固化机理作了讨论。并考察了不同分子量活性聚醚对环氧树脂的增韧作用。结果表明,此活性聚醚对环氧树脂增韧效果明显,固化树脂综合性能较好。     

在Bu_2SnO-Bu_3PO_4缩合物的存在下以端羟基聚醚增韧环氧树脂

工业中大量生产的端羟基聚醚 ,由于羟基的反应活性不够 ,不能直接用于增韧胺类固化的环氧树脂 .Bu2 SnO Bu3PO4 缩合物能催化羟基对环氧基的加成反应 .本文研究在Bu2 SnO Bu3PO4 缩合物Sn P6 70 0的存在下以端羟基聚四氢呋喃 (PTMG)增韧芳香胺 4,4′ 二氨基二苯砜 (DDS)固化的环氧树脂 .PTMG首先与环氧树脂反应生成嵌段共聚物 ,在固化时发生微相分离 .分散相的尺寸在有利于增韧的范围内 .PTMG在分子量与浓度适当时 ,能使树脂的断裂韧性大大提高 ;抗弯强度也有显著提高 ,而Tg 和模量略有降低 .     

氟碳链封端聚醚酰亚胺改性环氧树脂的相分离研究

采用差示扫描量热仪(DSC), 扫描电子显微镜(SEM)和时间分辨光散射(TRLS)研究不同分子量的氟碳链封端聚醚酰亚胺对改性环氧树脂的相分离的影响. 结果表明, 氟碳链端基的引 入, 由于低表面能氟碳链封端聚醚酰亚胺的阻隔作用, 而使相分离速度降低, 相结构演变时间缩短, 固化后的相结构相间距缩小. 随着氟碳链封端聚醚酰亚胺分子量的增加, 相结构由分散相转变为双连续相. 因此可以通过改变聚醚酰亚胺的端基及分子量调控相结构.     

氟碳链封端聚醚酰亚胺改性环氧树脂的相分离研究--分子量的影响

采用差示扫描量热仪(DSC), 扫描电子显微镜(SEM)和时间分辨光散射(TRLS)研究不同分子量的氟碳链封端聚醚酰亚胺对改性环氧树脂的相分离的影响. 结果表明, 氟碳链端基的引入, 由于低表面能氟碳链封端聚醚酰亚胺的阻隔作用, 而使相分离速度降低, 相结构演变时间缩短, 固化后的相结构相间距缩小. 随着氟碳链封端聚醚酰亚胺分子量的增加, 相结构由分散相转变为双连续相. 因此可以通过改变聚醚酰亚胺的端基及分子量调控相结构.     

热塑性聚醚酰亚胺改性四官能度环氧树脂的相分离研究──固化剂用量的影响

以DSC、TRLS和SEM等方法研究了固化剂DDS用量对苯端基聚醚酰亚胺(P-PEI)改性4,4'-二氨基二苯甲烷四缩水甘油环氧树脂(TGDDM)体系的固化速率及相结构的影响.结果表明,20phrP-PEI改性环氧体系在150℃固化时,随DDS量增加,固化反应速率增大,相分离时间提前,形成了不同的相结构,解释了DDS量对粘接剪切强度的影响.     

温度效应对氟链封端聚醚酰亚胺改性环氧树脂相分离的影响

用差示扫描量热仪(DSC)、扫描电镜(SEM)和时间分辨光散射(TRLS)比较了全氟碳链封端和苯环封端聚醚酰亚胺改性环氧树脂在不同温度下的相分离.结果表明,与P-blend相比,F-blend的固化速度和相分离速度较慢,诱导期和相结构固定时间推迟,相间距较小.升高温度,相间距因相分离速度加快而增大,同时由于全氟碳链端基引起的差异减小.因此,通过改变固化温度和聚醚酰亚胺的端基来降低聚醚酰亚胺的表面能,可以在一定程度上调控反应诱导相分离体系的相结构,并获得相间距较小的双连续结构.     

聚醚多元醇对环氧树脂的增韧改性

通过力学性能、热性能以及扫描电镜等方法研究了聚醚多元醇对环氧树脂-酸酐体系的增韧效果。结果表明:聚醚多元醇在环氧固化过程中分相析出,呈现出较好的增韧效果;在环氧-酸酐体系中,大分子量聚醚多元醇的增韧效果不如小分子量的;而由环氧乙烷封端的聚醚多元醇,由于含有与环氧树脂相容的聚环氧乙烷(PEO)链段,分散相与环氧母体间能够形成良好的界面作用,也体现出良好的增韧效果。     

丁腈橡胶和聚乙二醇增韧环氧树脂制备胶粘剂及性能研究

本文在加热下环氧树脂(Polyethylene Glycol, EP)开环与端羧基丁腈橡胶(carboxyl-terminated Butadiene acrylonitrile, CTBN)与发生酯化反应生成预聚物,然后选用单一固化剂聚醚胺(Polyetheramine, D400)和混合固化剂聚乙二醇(Polyethylene Glycol, PEG,Mn=2000)与二乙基甲苯二胺(Diethyltoluene diamine, DETDA)作用下固化及粘接木块。重点探讨CTBN、EP、D400和PEG与DETDA各组成的用量对环氧树脂基粘胶性能的影响,并通过红外判定主要官能团反应,重点探讨胶粘固化物的润湿性、吸水性、拉伸强度和热重手段评价其环氧树脂粘胶性能。结果表明随着CTBN用量的增加,增韧环氧树脂的固化效果越来越好,但是增加到一定程度,有副反应的作用导致其固化效果与粘性都会逐渐降低。结论：对固化物进行表征综合评价,CTBN、EP和固化剂的质量比为1∶5∶2时,其粘性最强,韧性最高,进一步研究有望获得市场欢迎的产品。     

丙烯酸酯封端环氧丙烷聚醚聚氨酯与双酚A型环氧树脂共混固化体系

丙烯酸酯封端环氧丙烷聚醚聚氨酯与双酚Ａ型环氧树脂共混固化体系丁伦汉华道本黄家贤＊韩敏（南开大学化学系天津３０００７１）（天津市聚氨酯泡沫材料厂天津）关键词环氧树脂，聚环氧丙烷，共混物，制备１９９６－１１－２２收稿，１９９７－０５－１３修回国家自然科学...     

热塑性聚醚酰亚胺改性四官能度环氧树脂的相分离研究：Ⅳ.聚醚 …

研究了不同用量新型苯端基聚醚酰亚胺对其改性４,４,‘－二氨基二苯甲烷四缩水甘油醚环氧树脂９ＴＧＤＤＭ）／４,４’－二氨基二苯砜体系的固化速度及相结构的影响。结果表明,随着ＰＥＩ用量的增加,固化反应速度增大,形成了不同的相结构。解释了ＰＥＩ用量对粘接剪切强度的影响。     

EPOXY RESINS TOUGHENED WITH CARBOXYL TERMINATED POLYETHERS

Carboxyl terminated polyethers, the adducts of hydroxyl terminated polytetrahydrofuran and maleic anhydride, were used as toughener for epoxy resins. The morphology of the toughened resins was investigated by means of turbidity measurement, dynamic mechanical testing and scanning electron microscope observation. It turned out that the molecular weight and the carboxyl content of the polyether and the cure conditions are important factors, which affect the particle size of the polyether-rich domains and, in turn, the mechanical properties of the cured resin. Carboxyl terminated polytetrahydrofurans have a low glass transition temperature, and in appropriate amount they do not affect the thermal resistance of the resin. These advantages make them preferable as toughener for epoxy resins.     

A STUDY ON THE TOUGHENING OF EPOXY RESIN BY HTBN-EPOXY RESIN PRECOPOLYMER

A novet toughened epoxy resin was obtained by using aprecopotymer of epoxy resin and hydroxy-terminated butadiene-acrylonitrilecopolymer(HTBN)and amine curing agent.The cured toughened resin hasexcellent mechanical properties due to the two-phase structure,which has beenobserved from SEM and TEM.     

聚丙撑碳酸酯增韧环氧树脂的研究

研究了聚丙撑碳酸酯（ＰＰＣ）对环氧树脂（ＥＰ）的改性作用、加入２０～３０Ｐｈｒ的ＰＰＣ，环氧树脂力学性能可以大幅度提高，粘接剪切强度为１２３３ＭＰａ，冲击强度为１６．７８ｋＪ／ｍ２；而纯环氧树脂固化物，其剪切强度为９．３６ＭＰａ，冲击强度为９．９９ｋＪ／ｍ２。ＳＥＭ和ＤＳＣ观测表明ＰＰＣ／ＥＰ体系呈两相结构。     

Studies on thermal, mechanical and morphological behaviour of caprolactam blocked methylenediphenyl diisocyanate toughened bismaleimide modified epoxy matrices

Diglycidyl ether of bisphenol A epoxy resin (DGEBA, LY 556) was toughened with 5%, 10% and 15% (by wt) of caprolactam blocked methylenediphenyl diisocyanate (CMDI) using 4,4′-diaminodiphenylmethane (DDM) as curing agent. The toughened epoxy resin was further modified with chemical modifier N,N′-bismaleimido-4,4′-diphenylmethane (BMI). Caprolactam blocked methylenediphenyl diisocyanate was synthesized by the reaction of caprolactam with methylenediphenyl diisocyanate in presence of carbon tetrachloride under nitrogen atmosphere. Thermal properties of the developed matrices were characterized by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), heat distortion temperature (HDT) and dynamic mechanical analysis (DMA). Mechanical properties like tensile strength, flexural strength and impact strength were tested as per ASTM standards. The glass transition temperature (T_g) and thermal stability were decreased with increase in the percentage incorporation of CMDI. The thermomechanical properties of caprolactam blocked methylenediphenyl diisocyanate toughened epoxy resin were increased by increasing the percentage incorporation of bismaleimide. The values of impact strength for epoxy resin were increased with increase in the percentage concentration of CMDI. The homogeneous morphology of CMDI toughened epoxy resin and bismaleimide modified CMDI toughened epoxy resin system were ascertained from scanning electron microscope (SEM).     

Curing kinetics and mechanisms of polysulfone nanofibrous membranes toughened epoxy/amine systems using isothermal DSC and NIR

Curing kinetics and mechanisms of polysulfone nanofibrous membranes toughened TGDDM/DDS were investigated by using isothermal DSC and NIR, and compared to those of TGDDM/DDS and PSF films toughened TGDDM/DDS. At early curing stage, the curing rate of nanofibrous membranes toughened system was faster than those of other two systems, whereas the final conversion of toughened systems was lower than that of resin matrix. Most of the primary amine was consumed by gelation and the concentration of secondary amine reached the maximum around gelation. The faster consuming rates of primary and secondary amines in nanofibrous membranes toughened system resulted in higher concentration of hydroxyl groups and tertiary amines at gelation, which led to larger amounts of branching and crosslinking compared to resin matrix. The comparison of the results obtained from two methods showed that the epoxide conversion exhibited identical variations as a function of time, as well as the curing rate.     

Interface and properties of epoxy resin modified by elastomeric nano-particles

Epoxy resin has been widely used as structuralmaterials and adhesives in electronics, aerospace in-dustries and etc. for its impressive overall properties.However, epoxy network is brittle and notch sensitive,which restricts its application scope. As a re…     

侧链液晶聚醚螯合树脂研究进展

相对于传统聚醚螯合树脂,侧链液晶聚醚型螯合树脂由于刚性介晶基元的引入,赋于了聚醚分子更好的使用性能,具有热稳定性好、吸附容量大、离子选择性高、易于设计与合成等优势,成为近年来树脂领域研究的热点之一。本文介绍了近年来国内外侧链液晶聚醚螯合树脂的合成、性能与应用现状。最后依据对侧链液晶聚醚螯合树脂机械性能、吸附选择性、再生性能以及环保性能的使用要求,对其分子设计与合成方法及新应用领域进行了展望。     

聚醚扩链脲增韧环氧树脂体系的冲击性能及其断裂面形态结构

聚醚扩链脲增韧环氧树脂体系的冲击性能及其断裂面形态结构     

STUDY ON THE EPOXY RESIN TOUGHENED BY HYDROXY-TERMINATED BUTADIENE-ACRYLONITRILE COPOLYMER

Toughened epoxy resin with excellent properties was obtained by adding organic acid anhydride curing agent and hydroxy-terminated butadiene-acrylonitrile copolymer (HTBN), which is cheaper than CTBN. The anhydride reacts with both epoxy groups on epoxy resin and hydroxyl groups on HTBN. As a result the soft long chains of HTBN and the rigid chain of epoxy resin form one network, giving the resin toughness. Two-phase structure of the toughened resin was observed by SEM and TEM.