双酚A型苯并噁嗪与酚醛型环氧树脂共混体系的固化反应与热性能

将双酚A型苯并噁嗪(Ba)和酚醛型环氧树脂(F-51)按照不同的质量比进行熔融共混,并固化制备了浇铸体。研究结果表明:环氧树脂的加入降低了苯并噁嗪的黏度,改善了苯并噁嗪的加工工艺性。随着环氧树脂含量的增加,Ba/F-51共混体系的DSC固化反应峰值温度向高温方向移动。在F-51环氧树脂的加入量低于50%的范围内,随环氧树脂加入量增加,Ba/F-51共混树脂的交联密度和玻璃化转变温度均有明显提高,其中Ba/F-51=1.5体系的Tg最高为173.4℃,比纯苯并噁嗪提高了17.4℃。     

双马来酰亚胺树脂的增韧研究──橡胶的增韧

研究了无规端羧基丁腈橡胶对4,4＇-双马来酰亚胺基二苯甲烷/E-51环氧树脂/4,4＇-二氮基二苯砜体系的增韧作用,包括橡胶含量对固化树脂力学性能的影响,固化树脂两相结构的形成及其断裂形貌。在上述研究的基础上,分析了橡胶的增韧理论。     

乙烯基侧链环氧树脂对E-51/NBR体系的影响

采用新型乙烯基侧链环氧树脂(VE)与E-51环氧树脂/液体丁腈橡胶体系共混,用万能材料试验机、动态力学分析仪和扫描电镜表征了VE的含量对树脂/橡胶体系力学性能、玻璃化转变温度(Tg)、微观相态结构的影响.结果表明,利用VE与E-51、丁腈橡胶良好的相容性可以显著改善树脂/橡胶体系的相容性;添加了VE后,用液体丁腈橡胶改性过的环氧树脂韧性提高,并保持了较好的力学强度;当VE/E-51=4/6,NBR含量为20%(wt)时,其拉伸强度比纯E-51/NBR体系提高11.9%,弯曲强度提高31.3%,断裂伸长率提高14.8%;体系的Tg、微观相态结构都随VE的含量呈现出有规律的变化.     

端羧基丁腈橡胶和双酚A增韧混合环氧树脂体系的研究

本文以2-乙基-4-甲基咪唑(简称2,4-咪唑)为固化剂,研究了端羧基丁腈橡胶(简称CTBN)和CTBN/双酚A改性的双官能环氧E-51和四官能环氧F-76混合体系的热-机械性能、微观形貌和声发射响应。结果表明:加入5份CTBN,对混合环氧树脂体系的增韧效果不明显。加入5份CTBN和24份双酚A,使体系的韧性增加。但CTBN加入的顺序不同,其微观结构和力学性能不同,增韧效果亦不同。      

氰基苯并(口恶)嗪/环氧树脂共混体系的性能研究

采用三种带有氰基的苯并噁嗪(Ben)与环氧树脂(E51)共混,制备了Ben/E51共混体系.用红外光谱研究了Ben/E51共混体系的固化行为.利用TGA和DMA研究了Ben/E51固化物的耐热性能和动态力学性能,结果显示,共聚体系的分解温度与用酸酐或胺固化的环氧树脂相比提高了70～80℃,玻璃化转变温度提高了30～70℃.Ben/E51共混体系的力学性能和介电性能比苯并噁嗪树脂有明显提高.     

环氧树脂的韧化

本文研究了无规羧基丁腈橡胶/E-51环氧树脂/叔胺固化体系。分析比较了固化剂活性、橡胶用量,活性添加剂双酚-A等对环氧浇注体性能的影响。试验结果表明:固化剂活性低的体系,橡胶的增韧效果明显;橡胶增韧剂的含量以5～10phr为宜;双酚-A的加入,使增韧效果显著改善。     

端羧基丁腈橡胶改性环氧树脂的结构与性能

用液体端羧基丁腈橡胶(CTBN)对环氧树脂(EP)进行改性,合成了CTBN/EP预聚物,FT-IR分析表明,在反应中EP的环氧基开环后与CTBN的羧基反应生成了酯键。研究了CTBN/EP/聚醚胺(PEA)体系的力学性能,结果表明,随着CTBN含量的增大,其弯曲强度、拉伸强度降低,冲击强度、断裂伸长率增大,说明CTBN通过化学预聚改性的EP具有良好的韧性。SEM分析表明,固化过程中析出了橡胶相并均匀分散在环氧树脂基体中。     

橡胶增韧双马来酰亚胺树脂的研究

在 4 ,4 ' 双马来酰亚胺二苯基甲烷 (BMDPM) /o ,o' 二烯丙基双酚A(DABPA)的基础上引入羧基封端的丁腈橡胶 (CTBN)增韧剂和稀释剂 ,采用先分步预聚、后减压共混的工艺合成了一种热熔性的韧性双马来酰亚胺树脂。研究了不同丙烯腈含量的羧基封端的丁腈橡胶 (CTBN)及其不同用量对树脂工艺性能、力学性能和耐热性的影响     

CTBN改性双酚A型氰酸酯树脂的性能

为改善氰酸酯树脂的冲击韧性,在双酚A型二氰酸酯(BADCy)树脂中混入了不同含量的端羧基丁腈橡胶(CTBN).用差示扫描量热法(DSC)及红外光谱法(FTIR)对CTNB/BADCy共混体系的反应性研究发现,CTBN能促进BADCy低温下的三嗪环反应,但是使BADCy的后处理温度提高.SEM分析表明,当CTBN的含量(质量分数)大于15%后,有CTBN颗粒从BADCy中析出,形成两相结构,且随着CTBN含量的增大,分散相的粒径增大,在断口处产生的银纹和剪切带使BADCy/CTBN共混体系的韧性提高.当CTBN的含量为25%时体系的冲击强度提高了2.3倍.     

端羧基丁腈橡胶改性环氧树脂的结构与性能

用液体端羧基丁腈橡胶(CTBN)对固体环氧树脂(EP)进行改性,合成了CTBN-EP预聚物,研究了CTBN-EP/HTP-305体系的微观形貌、力学性能和热性能。研究结果表明,随着CTBN含量的增大,冲击强度及断裂伸长率显著提高,说明通过CTBN化学预聚改性的EP韧性提高,而体系的拉伸强度和热性能略有下降。动态热机械分析(DMA)测试体系的动态力学性能结果表明,体系出现了两相结构(Tg对应温度分别是-60℃和80℃～100℃)。扫描电镜(SEM)分析表明,固化过程中析出了橡胶相并均匀分散在环氧树脂基体中,形成了剪切空洞变形结构。     

二元共聚高吸油性树脂的合成及研究

以甲基丙烯酸十二酯与甲基丙烯酸丁酯为单体，水为分散相，ＢＰＯ为引发剂，采用悬浮聚合法，合成高吸油性树脂。研究了交联剂结构、交联剂浓度、共聚单体配比、引发剂用量等对高吸油树脂性能的影响。所制树脂可吸其自身重的１１倍左右的煤油、１６倍左右的苯。     

Effect of different copolymers (hydrogenated and non-hydrogenated, with different molecular weights and different content of styrene) in the compatibilization of PS + PP (80+20) polyblend

We have studied the effect of the addition of different compositions of several styrene / butadiene / styrene (SBS) triblock copolymers, hydrogenated and non-hydrogenated, with different molecular weights and different content of styrene, on the PS + PP (80+20) polyblend. We have determined the influence of these parameters on thermal and mechanical properties as well as on the observed morphology. As the composition of the hydrogenated copolymer or the copolymer with a similar content of styrene and butadiene was increased, the dispersion of particles increased, lowering remarkably their size and producing this way a better interfacial adhesion in the blend. Excluding the copolymer with similar content of styrene and butadiene in its structure, the rest of the copolymers show a strong tendency to form micelles or mesophases in the matrix as the amount of copolymer increases, improving some mechanical properties such as impact strength but deteriorating others like the yield and break stresses. On the other hand, the presence of compatibilizers, at any composition, does not have any effect on the thermal parameters of the blend. Nevertheless, the presence of PS, amorphous and the majority component in the blend, affects the crystallization process of PP, enhancing in a wide temperature range (from 125 °C to 40 °C) its crystallization process. Received: 14 November 2000 / Reviewed and accepted: 15 November 2000     

Effect of carboxyl-terminated poly(butadiene-co-acrylonitrile) (CTBN) concentration on thermal and mechanical properties of binary blends of diglycidyl ether of bisphenol-A (DGEBA) epoxy resin

Six blend samples were prepared by physical mixing of epoxy resin with varying concentrations of liquid carboxyl-terminated butadiene acrylonitrile (CTBN) copolymer having 27% acrylonitrile content. The blend samples were cured with aromatic amine. A comparative study of Fourier-transform infrared (FTIR) spectra showed the modification as a result of chemical reactions between epoxide group, curing agent and CTBN. The tensile strength of cured blend samples decreased slightly from 11 to 46% where as the elongation-at-break showed an increasing trend with increasing rubber content, i.e., up to 25 phr, in the blend samples. Appreciable improvements in impact strength were also observed in the prepared blend systems. The glass transition temperature (T_g) of the epoxy resin matrix was slightly reduced on the addition of CTBN. The cured resin showed a two-phase morphology where the spherical rubber domains were dispersed in the epoxy matrix.     

丙烯酸2-乙基己酯与醋酸乙烯酯共聚合成高吸油性树脂的研究

以丙烯酸2－乙基己酯与醋酸乙烯酯为单体，采用悬浮聚合法，以单体自交联制得高吸油性树脂。对影响其吸油性能的多种因素，如单体配比、引发剂、油水相比的用量等，进行了系统的研究，得到的高吸油性树脂吸苯最高达16．1g/g，吸甲苯为14．8g/g，吸环己烷为13．3g/g，吸煤油为12．5g/g，可用于河面、海洋浮油的回收及工厂废水处理等领域.     

丙烯酸酯与甲基丙烯酸酯的共聚及性能研究

采用悬浮聚合法，以丙烯酸－２－乙基－己酯与甲基丙烯酸十二酯为单体，合成了共聚型高吸油性树脂。研究了共聚单体的配比、交联剂用量、引发剂用量诸因素对高吸油性树脂的性能影响。制得的树脂可以吸其自身质量的１１．８倍的煤油、１４．７倍的苯、６．５倍的泵油。     

酚醛环氧-环硫树脂的合成和表征

采用F-51环氧树脂与硫化剂在水溶液中反应制备F-51环氧-环硫树脂。聚合物用红外光谱,核磁共振进行了表征。研究了反应时间,反应温度,环硫树脂含量对凝胶时间的影响。实验结果表明,随着环硫树脂的量的增加,凝胶化时间逐渐缩短。同时,还对环氧-环硫树脂的折光指数进行了测试。     

Structural-mechanical relationship of epoxy compatibilized polyamide 6/polycarbonate blends

Polyamide 6 (PA6)/polycarbonate (PC) blends compatibilized with solid epoxy resin (bisphenol type-A) were prepared by extrusion followed by injection molding. The effects of epoxy resin on the microstructure, tensile, impact and compatibility of the PA6/PC blends were investigated. The results showed that both the tensile modulus and elongation at break of PA6/PC blends were inferior as compared to their parent polymers. This resulted from incompatibility between the PA6 and PC phases. SEM observation revealed that the introduction of 0.5 part per hundred (phr) epoxy resin into the PA6/PC75/25 blend yields a finer dispersion of PC phase in PA6 matrix. The boundaries between the PC domains and PA6 matrix became obscure with the incorporation of 1 phr epoxy resin. Such an improvement in compatibility was suggested to be resulted from the formation of in situ epoxy bridged PA6-PC block copolymer in the blend during compounding. Consequently, the tensile modulus, yield strength and impact strength of the PA6/PC 75/25 blend improved considerably with increasing epoxy content.     

阴离子聚合尼龙6/ABS合金的制备与性能

采用缩二脲（HDI）封端端羟基丁腈橡胶预聚物,制备大分子橡胶改性活化剂,以氢氧化钠为催化剂,选择不同配比的ABS树脂加入熔融己内酰胺单体中,确定聚合温度为160℃~180℃,通过阴离子聚合制得ABS/尼龙6（PA6）共混物。在原位合成ABS改性尼龙体系中,以橡胶改性剂作为ABS与尼龙的相容剂,当ABS用量为m（ABS）...