工艺条件对CTBN增韧环氧树脂性能的影响

本文以 ２－乙基－４－甲基咪唑为固化剂，以ＣＴＢＮ／双酚Ａ为增韧剂，研究了双官能环氧Ｅ－５１和四官能环氧Ｆ－７６混合体系的结构形态和力学性能，考察了工艺条件对其性能的影响，讨论了ＣＴＢＮ和双酚Ａ的增韧机理。     

ACR-g-VC冲击改性剂的性能与应用研究

对丙烯酸酯接枝氯乙烯共聚物（ACR-g-VC）增韧聚氯乙烯（PVC）体系的力学性能和加工性能进行了研究,通过与丙烯酸酯核－壳接枝共聚物（ACR）、氯化聚乙烯（CPE）增韧PVC体系的加工性能进行对比,发现其加工性能与ACR增韧PVC体系的加工性能接近。通过对PVC/ACR-g-VC与PVC／ACR的力学性能和形态结构的对比,分析了两种体系增韧效果差异的原因。实际应用研究表明,ACR-g-VC与CPE共同使用时有协同增韧作用。     

新型复相陶瓷刀具材料Jx-2-I协同增韧补强机理的研究

本文研制成功的新型陶瓷刀具材料—ＳｉＣ晶须（ＳｉＣｗ）增韧和ＳｉＣ颗粒弥散增韧Ａｌ２Ｏ３陶瓷刀具Ｊｘ－２－Ｉ,该刀具材料具有高的抗弯强度和断裂韧性等优点;对比Ａ（Ａｌ２Ｏ３）、ＡＰ（Ａｌ２Ｏ３／ＳｉＣｐ）、ＡＷ（Ａｌ２Ｏ３／ＳｉＣｗ）、Ｊｘ－１（Ａｌ２Ｏ３／ＳｉＣｗ）和Ｊｘ－２－１（Ａｌ２Ｏ３／ＳｉＣｐ／ＳｉＣｗ）等陶瓷材料的力学性能可以看出,在Ｊｘ－２－Ｉ材料中具有明显的增韧补强叠加效应;本文在热失配分析和微观结构观察的基础上详细研究了Ｊｘ－２－Ｉ刀具材料的增韧补强机理,系统研究了Ｊｘ－２－Ｉ中各种增韧补强机理之间的协同效应。     

新型可溶性PI/SiO2纳米复合材料的研究

通过正硅酸乙酯与聚酰胺酸的Ｎ－甲－２－吡咯烷溶液的溶胶－凝胶反应,制备出新型的聚酰亚胺／二氧化硅纳米复合材料。用紫外－可见光、电镜、高阻计等手段对其光学透明性、微观结构、热稳定性、力学性能、绝缘性能,以及其特有的溶解性能进行了研究。结果表明,随ＳｉＯ２含量的增加,复合材料中ＳｉＯ２粒子尺寸逐渐增大,光学透明性降低,热稳定性增加,溶解性减弱,力学性能先增后降,并在一定的范围内同时具有增强增韧效果。     

纳米CaCO3粒子对PVC改性的研究

根据刚性粒子增韧改性的理论，采用填加纳米CaCO3的PVC/CPE体系，研究了偶联剂的选择及用量，纳米CaCO3的含量，基本韧性等对力学性能及亚微观结构的影响。并用SEM及TEM进行有关形态结构的表征。     

ACR增韧聚碳酸酯/聚乳酸合金的制备与性能研究

以核壳结构的丙烯酸酯类树脂(ACR)作为增韧剂,对聚碳酸酯(PC/)聚乳(酸PLA)合金进行增韧改性,研究了ACR用量对合金力学性能、热性能和微观形态的影响。结果表明:加入一定用量的ACR,合金的冲击强度大幅度提高,而其他力学性能影响较小;合金比例为PC/PLA=90/10时,二者的相容性良好,体系只有一个玻璃化温度;ACR的用量对合金的微观形态有一定的影响。     

增韧SMA的制备及与PC的共混改性

研究了ＳＢＳ增韧ＳＭＡ树脂体系,采用二次共混工艺,用１５％（质量）的ＳＢＳ可以很好地增韧ＳＭＡ树脂;用增韧的ＳＭＡ树脂与ＰＣ进行共混,考察了体系的力学性能和微观相结构,制备出综合力学性能良好、加工性能优于纯ＰＣ的共混材料。当增韧ＳＭＡ／ＰＣ为２０／８０时,共混材料的力学性能与纯ＰＣ相近,达到了预期改性ＰＣ的目的。     

新型丙烯-乙烯共聚物增韧聚丙烯的研究

丙烯-乙烯共聚物Vistamaxx（VM）是一种丙烯摩尔含量占70％以上的新型弹性体。用VM增韧聚丙烯（PP），考察了PP／VM共混物的力学性能、微观形态结构以及结晶性能，并与乙烯-辛烯共聚物（POE）与PP的共混体系进行了对比。结果表明，常温下VM增韧效果优于POE，PP／VM体系拉伸性能优于PP／POE体系；VM在PP中表现出比POE更好的分散性；VM具有与PP相同的晶型，VM的加入细化了PP的晶粒。     

微观结构与ABS产品性能的关系 (Ⅰ)ABS树脂的形态结构及力学性能

从ABS树脂的形态结构和力学性能2个方面论述了ABS树脂的微观结构与产品性能之间的关系。首先通过投射电镜(TEM)照片描述了ABS树脂的微观结构,然后讨论了影响ABS树脂性能的因素,最后初步探讨了橡胶增韧ABS树脂的机理。     

微观结构与ABS产品性能的关系 （Ⅱ）ABS树脂的增韧机理

从ABS树脂的形态结构和力学性能2个方面综述了ABS树脂的微观结构与产品性能之间的关系。首先通过投射电镜（TEM）照片描述了ABS树脂的微观结构,然后讨论了影响ABS树脂性能的因素,最后初步探讨了橡胶增韧ABS树脂的机理。     

Effect of matrix ductility on the fracture behavior of rubber toughened epoxy resins

This paper investigates the effect of matrix ductility on toughness in a carboxyl-terminated butadiene-acryionitrile copolymer (CTBN) toughened diglycidyl ether of bisphenol-A (DGEBA)-piperidine system. Two kinds of epoxides were blended separately into this system to change the matrix ductility. One was a rigid and polyfunctional 4,4′-diaminodiphenol methane (MY720), and the other was a flexible diglycidyl ether of propylene glycol (DER732). The matrix T_g was significantly changed, but without alteration of the microstructure of the dispersed rubbery phase. The result of fracture energy tests reveals that the toughness of the neat epoxy resins increases slightly with the increase in the resin ductility. The toughness of the rubber-modified epoxy resins increases strongly with matrix ductility. Studies on the morphology of the toughened systems and their fracture surfaces indicate that the size of the plastic deformation zone under constant rubbery-phase morphology is determined by the multiple but localized plastic shear yielding. Increasing matrix ductility increases the size of the plastic deformation zone by inducing more extensive shear yielding. In addition, fracture surfaces reveal that as the matrix rigidity is increased, an increasing proportion of the fracture energy is dissipated by rubber cavitation during crack initiation.     

反应性端基聚丁二烯系列液体橡胶在环氧树脂改性增韧方面的应用

综述了含反应性端基聚丁二烯系列液体橡胶（以下简单PBLR）品种、性能及特点，概括比较了PBLR改性增韧环氧树脂方法及特点；分别列举了PBLR改性环氧树脂在微机电浇注料，树脂砂轮，水利机械涂敷，电子灌封及飞机粘合剂等方面的应用。     

环氧树脂及其改性树脂的低温性能分析和增韧研究(Ⅰ):低温性能分析

对环氧树脂及其改性后树脂的低温性能、动态性能进行了试验研究 ,得到环氧树脂及其增韧树脂在低温情况下材料特性 ;并对材料的断口照片进行了分析 ,得出在低温、低载荷作用下的橡胶增韧双酚A改性的环氧树脂共混体系中 ,共混体性能此时以橡胶颗粒的性能作为主导性能出现。     

CTBN结合纳米SiO_2改性环氧树脂及增韧机理

以端羧基液体丁腈橡胶(CTBN)结合纳米SiO2(n-SiO2)对环氧树脂(ER)增韧,采用正交法制备了室温固化双组分环氧胶粘剂。通过力学性能测试,红外、示差扫描量热及电镜分析对体系的性能进行了研究。结果表明,环氧树脂与双增韧剂质量比为8∶1,CTBN与n-SiO2质量比为2∶1,甲组分在180℃下反应2.5 h条件下制得的胶粘剂剪切强度、剥离强度、冲击强度分别达到33.85 MPa、5.92 kN/m、18.24 kJ/m2。CTBN和n-SiO2都与ER发生了作用,且双增韧剂增韧的固化产物热稳定性较好。CTBN、n-SiO2、双增韧剂增韧ER的机理分别为颗粒铆钉所诱发的剪切变形机理、银纹钝化机理、剪切变形与银纹钝化相结合形成的韧窝机理。     

Effect of rubber/matrix interfacial modifications on the properties of a rubber-toughened epoxy resin

The interface of a rubber-toughened epoxy resin was modified by using epoxide end-capped carboxyl-terminated butadiene and acrylonitrile random copolymer (CTBN). The end-capping epoxides were formulated with different ratios of flexible diglycidyl ether of propylene glycol (DER732) and rigid diglycidyl ether of bisphenol-A (Epon 828). The microstructure and the fracture behavior of these rubber-modified epoxy resins were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The thermal and mechanical properties were also investigated. With an increase in the amount of end-capping DER732, the interfacial zone of an undeformed rubber particle and the degree of cavitation of the rubber cavity on the fracture surface were greatly increased. At the maximal addition of DER732, fracture energy (GIc) for this toughened epoxy resin containing 10phr CTBN rubber increases up to 2.4 fold compared to that of a conventional CTBN-toughened epoxy resin, but the thermal and the mechanical properties remained quite unaffected. The modification on the interfacial property provides a new technique in the improvement of fracture toughness of a rubber-toughened epoxy resin.     

Enhanced fracture toughness of epoxy resins with novel amine‐terminated poly(arylene ether sulfone)–carboxylic‐terminated butadiene‐acrylonitrile–poly(arylene ether sulfone) triblock copolymers

Amine‐terminated poly(arylene ether sulfone)–carboxylic‐terminated butadiene‐acrylonitrile–poly(arylene ether sulfone) (PES‐CTBN‐PES) triblock copolymers with controlled molecular weights of 15,000 (15K) or 20,000 (20K) g/mol were synthesized from amine‐terminated PES oligomer and commercial CTBN rubber (CTBN 1300x13). The copolymers were utilized to modify a diglycidyl ether of bisphenol A epoxy resin by varying the loading from 5 to 40 wt %. The epoxy resins were cured with 4,4′‐diaminodiphenylsulfone and subjected to tests for thermal properties, plane strain fracture toughness (K_IC), flexural properties, and solvent resistance measurements. The fracture surfaces were analyzed with SEM to elucidate the toughening mechanism. The properties of copolymer‐toughened epoxy resins were compared to those of samples modified by PES/CTBN blends, PES oligomer, or CTBN. The PES‐CTBN‐PES copolymer (20K) showed a K_IC of 2.33 MPa m^0.5 at 40 wt % loading while maintaining good flexural properties and chemical resistance. However, the epoxy resin modified with a CTBN/8K PES blend (2:1) exhibited lower K_IC (1.82 MPa m^0.5), lower flexural properties, and poorer thermal properties and solvent resistance compared to the 20K PES‐CTBN‐PES copolymer‐toughened samples. The high fracture toughness with the PES‐CTBN‐PES copolymer is believed to be due to the ductile fracture of the continuous PES‐rich phases, as well as the cavitation of the rubber‐rich phases. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1556–1565, 2002; DOI 10.1002/app.10390     

Effect of aluminum silicate on the impact and adhesive properties of toughened epoxy resins

Carboxyl randomized poly(2-ethyl hexyl acrylate) (CRPEHA) and epoxy randomized poly(2-ethylhexyl acrylate) (ERPEHA) have been used to toughen aluminum silicate filled epoxy resin cured with 4,4′-diaminodiphenyl methane. CRPEHA (A-1) and ERPEHA (B-1) were synthesized by solution polymerization technique in the form of liquid rubbers. The toughened epoxy networks were evaluated for their impact and adhesive properties. The epoxy/liquid rubber compositions were varied to study the effect of toughener concentration on the adhesive and impact properties for both filled and unfilled systems. Improved properties were obtained for epoxy resins toughened with (1 : 1) mixture of CRPEHA and ERPEHA. Lap shear strength of filled epoxy resins was higher than that of unfilled ones but the reverse was the case for impact strength. Analysis of adhesive failure surfaces by scanning electron microscopy (SEM) indicated the presence of a two-phase microstructure.     

Effect of aramid-CTBN block copolymer on phase structure and toughness of cured epoxy resins modified with carboxy-terminated butadiene acrylonitrile copolymer (CTBN)

An Aramid-CTBN block copolymer was added to a Bisphenol-A type epoxy resins modified with CTBN. With the addition of the copolymer, the impact strength of the CTBN-modified systems was about twelve times higher than that of the unmodified system. Transmission electron micrographs of the block copolymer-epoxy system showed that the diameter of CTBN-dispersed phase decreased and a number of fine CTBN phases were dispersed in the matrix. The deformability of matrix in these systems increased with a dispersion of the fine CTBN phase. It is concluded that the improvement of toughness of the cured resins is due to the increases in the ductility of epoxy matrix by the incorporating of the dispersion of the fine CTBN phase in the matrix.     

Mechanical and tribological properties of epoxy modified by liquid carboxyl terminated poly(butadiene-co-acrylonitrile) rubber

Diglycidyl ether of bisphenol A (DGEBA)-based epoxy resin was modified using liquid carboxyl-terminated poly(butadiene-co-acrylonitrile) (CTBN) rubber. The liquid CTBN contents used ranged from 2.5 to 20 parts per hundred parts of resin (phr). Mechanical properties of the modified resins were evaluated and the microstructures of the fracture surfaces were examined using SEM technique. The changes in storage modulus and the glass transition temperature were also evaluated using dynamic mechanical analysis (DMA). The tribological tests were performed using a ball-on-disc tribometer. The worn surfaces and the ball counter-mates after tribological tests were investigated using optical microscope technique. The results revealed the influence of liquid CTBN content on mechanical and tribological properties, and also microstructure of the modified epoxy resins. Impact resistance increased whereas the storage modulus and the hardness decreased when the CTBN rubber was introduced to the epoxy network. The coefficient of friction of the CTBN-modified epoxy was lower than that of the neat epoxy. The CTBN content of lower than 10 phr was recommended for improving the wear resistance of epoxy resin. Changes in tribological properties of the CTBN-modified epoxy correspond well to those in mechanical changes, especially the toughness properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Dynamic mechanical properties and adhesive strengths of epoxy resins modified with liquid rubber. II. Modification with CTBN

The dynamic mechanical properties and the adhesive strengths of epoxy resins-CTBN blend systems and epoxy resins-CTBNX blend systems were investigated. Both CTBN blend and CTBNX blend systems were proved to be partially compatible with the dynamic mechanical measurement. In the case of CTBN blend systems, the more blending of CTBN, the more the compatibility increased. On the other hand, CTBNX-20 was more compatible than CTBNX-30 but less than CTBNX-40. In any case, the blending of CTBN or CTBNX reduced the nonreacted part of the epoxy resins cured at room temperature. The adhesive strengths were evaluated as a function of the storage modulus with altering temperature and altering rubber content. Both procedures were proved to be equal.