环氧树脂的共混增韧改性研究

环氧树脂是一热固性树脂，固化后的环氧树脂的韧性较差，针对这一不足，详细介绍近几年来有关环氧树脂共混增韧改性的一些新的方法。     

无机纳米粒子在环氧树脂增韧改性中的应用

无机纳米粒子能够给聚合物赋以卓越的综合性能,为此,纳米材料在聚合物改性中的应用已成为聚合物改性领域中的一个研究热点。本文就近年来在环氧树脂增韧改性中应用的无机纳米粒子的种类、环氧树脂／无机纳米复合材料的制备方法及其应用研究进展进行了综述。     

有机硅改性环氧树脂在油墨中的应用

以Ph2SiCl2、Me2SiCl2、MeSiCl3为原料合成了分子量为2000左右含端羟基聚苯基甲基硅氧烷。以该硅树脂与E-20环氧树脂共缩聚制备的有机硅改性环氧树脂作为油墨连结料，与TiO2、增塑剂、溶剂等制成A组分，固化荆为B组分，由A、B组分所组成的油墨具有优良的移印、成膜性能。研究表明该油墨具有较高附着力，固化膜具有耐热、耐寒、耐溶剂和高电绝缘等优点，可作为在苛刻使用条件下移印和丝印的特种油墨。     

热塑性聚酰亚胺及其改性材料的制备与性能

聚酰亚胺具有优异的耐高温性能,但其熔融、加工性能较差,限制了其广泛应用。通过在聚酰亚胺分子结构中引入柔性基团、设计分子结构的异构化等方法,可制备热塑性聚酰亚胺,使得其加工性能得到改善,并可通过挤出、注塑等成型加工。本文在对热塑性聚酰亚胺单体及其树脂的合成方法进行综述的基础上,讨论了热塑性聚酰亚胺改性尼龙、聚醚醚酮、环氧树脂等材料的制备方法和性能特点,并对聚酰亚胺改性工程塑料的未来发展方向进行展望。     

胶粉的改性及其在热塑性弹性体中的应用

我国每年产生大量的废橡胶造成了严重的环境污染,作为废橡胶回收再利用的有效途径,胶粉的研究和应用受到广泛关注.本文介绍了胶粉的脱硫再生改性技术与表面活化改性技术及胶粉在热塑性弹性体中的应用,简述了胶粉基热塑弹性体的制备方法并比较了熔融共混法与动态硫化法的区别,概述了各类胶粉基热塑性弹性体的研究现状,着重介绍了胶粉基热塑弹...     

苯氧树脂增韧双酚A环氧树脂的研究

以双官能团环氧树脂和双酚Ａ为单体，制备高分子量苯氧树脂，通过ＦＴＩＲ对其分子结构进行分析后，将１０ｗｔ％苯氧树脂加入到Ｅ－４４环氧树脂中，用ＤＳＣ冲击仪和ＳＥＭ等对增韧效果的分析测定，固化反应活化能降低９％，冲击强度提高６３．２％，玻璃化温度提高了２８℃。     

聚醚砜改性环氧树脂体系粘弹性相分离的研究

采用光学显微镜、光散射和扫描电镜等技术对聚醚砜(PES)/环氧树脂/二(2,6-二甲基苯胺基)甲烷体系的相分离过程进行了研究. 实验结果表明在该体系的相分离的演化过程中存在着明显的慢动态相的粘弹性效应, 同时对于PES含量较低的体系(PES-13.2 wt%和15.9 wt%), 在120和140 ℃固化时均观察到二次相分离现象, 而PES含量较高的体系(PES-18.5 wt%), 在同样温度下固化时仅观察到一次相分离过程.     

有机在同聚物改性环氧树脂的方法与机理

综述了有机硅高聚物改性环氧树脂的各种改性方法、反应机理以及改性机理的研究进展。     

不同热塑性树脂改性热固性树脂体系反应诱导相分离过程的时间/温度依赖性

对几种不同热塑性树脂改性热固性树脂体系反应诱导相分离过程,包括UCST(最高互溶温度)、LCST(最低互溶温度)体系和含有复杂多步反应体系,在耐高温高分辨热台显微镜、流变仪和小角激光光散射仪上进行了研究.发现体系的反应诱导相分离时间/温度关系遵循Arrhenius方程.其相分离活化能对体系反应速率、粘弹性变化、体系中热塑性树脂的含量和分子量不敏感,也不受相分离检测手段的影响,而依赖于树脂化学环境相容性和交联反应的温度依赖性.对这一共性的物理本质进行了讨论.     

Phase behavior,crystallization, and nanostructures in thermoset blends of epoxy resin and amphiphilic star‐shaped block copolymers

This article reports thermoset blends of bisphenol A‐type epoxy resin (ER) and two amphiphilic four‐arm star‐shaped diblock copolymers based on hydrophilic poly(ethylene oxide) (PEO) and hydrophobic poly(propylene oxide) (PPO). 4,4′‐Methylenedianiline (MDA) was used as a curing agent. The first star‐shaped diblock copolymer with 70 wt % ethylene oxide (EO), denoted as (PPO‐PEO)₄, consists of four PPO‐PEO diblock arms with PPO blocks attached on an ethylenediamine core; the second one with 40 wt % EO, denoted as (PEO‐PPO)₄, contains four PEO‐PPO diblock arms with PEO blocks attached on an ethylenediamine core. The phase behavior, crystallization, and nanoscale structures were investigated by differential scanning calorimetry, transmission electron microscopy, and small‐angle X‐ray scattering. It was found that the MDA‐cured ER/(PPO‐PEO)₄ blends are not macroscopically phase‐separated over the entire blend composition range. There exist, however, two microphases in the ER/(PPO‐PEO)₄ blends. The PPO blocks form a separated microphase, whereas the ER and the PEO blocks, which are miscible, form another microphase. The ER/(PPO‐PEO)₄ blends show composition‐dependent nanostructures on the order of 10?30 nm. The 80/20 ER/(PPO‐PEO)₄ blend displays spherical PPO micelles uniformly dispersed in a continuous ER‐rich matrix. The 60/40 ER/(PPO‐PEO)₄ blend displays a combined morphology of worm‐like micelles and spherical micelles with characteristic of a bicontinuous microphase structure. Macroscopic phase separation took place in the MDA‐cured ER/(PEO‐PPO)₄ blends. The MDA‐cured ER/(PEO‐PPO)₄ blends with (PEO‐PPO)₄ content up to 50 wt % exhibit phase‐separated structures on the order of 0.5–1 μm. This can be considered to be due to the different EO content and block sequence of the (PEO‐PPO)₄ copolymer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 975–985, 2006     

Cure kinetics of epoxy resin and thermoplastic polymer

The cure kinetics and morphology of diglycidyl ether of bisphenol A (DGEBA) modified with polyvinyl acetate (PVAc) using diaminodiphenylmethane (DDM) as hardener were investigated through differential scanning calorimetry (DSC) and environmental scanning electron microscopy (ESEM). Isothermal curing measurements were carried out at 150, 120 and 80°C. The kinetic parameters were obtained using the general autocatalytic chemically controlled model. The comparison of the kinetic data indicates that the presence of PVAc does not change the autocatalytic nature of the cure reaction. Two T _g’s were observed in the fully cured samples of the modified systems. ESEM micrographies confirm the biphasic morphology.     

Reactive compatibilization of epoxy/polyorganosiloxane blends

A new thermoset material based on DGEBA with polyaminosiloxane curing agents is presented. The system shows reaction-induced compatibilization which prevents coalescence of polysiloxane and DGEBA rich domains, leading to gradient structured morphologies. The influence of curing temperature and/or chemical nature of the siloxane on the morphology and surface microhardness were examined. When siloxane is pre-reacted with epoxypropylphenylether (EPPE), a more homogeneous material is obtained. Microhardness profiles on the material are strongly influenced by the extension of the compositional gradients.     

Graft interpenetrating polymer networks composed of epoxy resin and urethane acrylate resin

For enhancing the interpenetratoin and/or compatibility of the simultaneous interpenetrating networks (SINs) composed of epoxy resin (epoxy) and urethane acrylate resin (UAR), the graft epoxy consisting of different lengths of poly(oxypropylene) (PO) side chains were synthesized and characterized. It was found that the graft epoxy composed of short PO side chains [MW 480, epoxy-g-PO(480)] showed a compatible system while if consisting of longer PO grafts [MW 950, epoxy-g-PO(950)] exhibited a partial microphase separation morphology. DSC measurements as well as the SEM or TEM observation indicated that the interpenetration between the two phases for epoxy/UAR SINs including epoxy-g-PO(480) was improved appreciably due to the excellent miscibility between the PO grafts and PO segments existing in the graft epoxy and the UAR network, respectively. In this case, for SIN(80/20) containing 10 wt % of epoxy-g-PO(480) the tensile strength increases by a factor of 2.70 compared with that of pure epoxy network. However, the improvement of interpenetration and/or compatibility between the two networks as well as the mechanical properties for SINs composed of epoxy-g-PO(950) are limited resulting in the partial microphase separation of epoxy-g-PO(950) network's own self. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3568–3574, 1999     

聚氨酯/环氧树脂互穿网络聚合物的性能研究

互穿聚合物网络（Interpenetrating polymer net-work,简称IPN）广泛应用的为聚氨酯基的互穿网络聚合物。其合成多集中在弹性体方面。本文用同步法合成的聚氨酯／环氧树脂互穿网络硬质泡沫塑料材料（简称PU／ERIPNF）,机械性能较好,并研究了其动态力学性能及形态变化。     

Synthesis of a novel epoxy resin containing naphthalene moiety and properties of its cured polymer with phenol novolac

A new epoxy resin (Bis-ENA) containing naphthalene structure linked with a 1,4-bis(isopropylidene)phenylene was synthesized and was confirmed by elemental analysis, infrared spectroscopy, and ¹H nuclear magnetic resonance spectroscopy. To estimate the effect of naphthalene moiety on the cured polymer, an epoxy resin (Bis-EP) having phenyl moiety was synthesized, and curing behaviors of Bis-ENA and Bis-EP with phenol novolac were evaluated by differential scanning calorimetry. The incorporation of naphthalene structure into the resin backbone increased the curing temperature and reduced the curing reactivity. Thermal properties of the cured polymers obtained from Bis-ENA and Bis-EP with phenol novolac were examined by thermomechanical analysis and dynamic mechanical analysis. Mechanical properties and moisture resistance were evaluated by flexural strength, flexural modulus, and moisture absorption measurements. The cured polymer obtained from Bis-ENA showed higher glass transition temperature, higher flexural modulus, lower thermal expansion, and lower moisture absorption than that from Bis-EP. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3063–3069, 1999     

Reaction of epoxy resin and hyperbranched polyacids

The condensation reaction between two different epoxy resins and a hyperbranched polyester (MAHP) [poly(allyloxy maleic acid‐co‐maleic anhydride)] was studied. We compared two kinds of diglycidyl ether bisphenol A type of epoxy resins with different molecular weights, that is, epoxy resin GY240 (M = 365 g/mol) and GT6064 (M = 1540 g/mol) in this reaction. The results showed a marked difference in their reaction pattern in terms of ability to form crosslinked polymer networks with MAHP. For the former low‐molecular‐weight epoxy resin, no crosslinking could be observed in good solvents such as THF or dioxane within the set of reaction conditions used in this study. Instead, polymers with epoxide functional degrees between 0.34 and 0.5 were formed. By contrast, the latter high‐molecular‐weight epoxy resin, GT6064, rapidly produced highly crosslinked materials with MAHP under the same reaction conditions. The spherical‐shape model of hyperbranched polymer was applied to explain this difference in reaction behavior. Hence, we have postulated that low‐molecular‐weight epoxy resins such as GY240 are unable to crosslink the comparatively much bigger spherically shaped MAHP molecules. However, using high‐molecular‐weight epoxy resins greatly enhances the probability of crosslinking in this system. Computer simulations verified the spherical shape and condensed bond density of MAHP in good solvents, and submicron particle analysis showed that the average MAHP particle size was 9 nm in THF. Furthermore, the epoxy‐functionalized polyesters were characterized by ¹H NMR and FTIR, and the molecular weights and molecular‐weight distributions were determined by size‐exclusion chromatography. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4457–4465, 2000     

Thermal and mechanical properties of a dendritic hydroxyl‐functional hyperbranched polymer and tetrafunctional epoxy resin blends

Blends of a tetrafunctional epoxy resin, tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM), and a hydroxyl‐functionalized hyperbranched polymer (HBP), aliphatic hyperbranched polyester Boltorn H40, were prepared using 3,3′‐diaminodiphenyl sulfone (DDS) as curing agent. The phase behavior and morphology of the DDS‐cured epoxy/HBP blends with HBP content up to 30 phr were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM). The phase behavior and morphology of the DDS‐cured epoxy/HBP blends were observed to be dependent on the blend composition. Blends with HBP content from 10 to 30 phr, show a particulate morphology where discrete HBP‐rich particles are dispersed in the continuous cured epoxy‐rich matrix. The cured blends with 15 and 20 phr exhibit a bimodal particle size distribution whereas the cured blend with 30 phr HBP demonstrates a monomodal particle size distribution. Mechanical measurements show that at a concentration range of 0–30 phr addition, the HBP is able to almost double the fracture toughness of the unmodified TGDDM epoxy resin. FTIR displays the formation of hydrogen bonding between the epoxy network and the HBP modifier. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 417–424, 2010     

Preparation and properties of aniline chain-extended thermoplastic epoxy resin using triphenylphosphine as catalyst

Thermoplastic resins have been widely used in fiber reinforced polymer composites because of its recyclability and short cycle times. However, the high viscosity after heating and melting restricts its infiltration on the surface of fiber. In this study, a series of thermoplastic epoxy resins were prepared via the chain extension reaction of epoxy groups with liquid aniline using triphenylphosphine (TPP) as catalyst. The relationship between polymer network structure and performance was comprehensively investigated. The solubility tests indicated that excessive aniline or TPP facilitated the crosslinking of resins. Besides, on the premise of thermoplasticity, appropriate TPP could increase the degree of chain extension, molecular weight, and glass transition temperature of resins. Furthermore, the in-situ polymerization process facilitated infiltration between epoxy resin and the fibers before chain extension reaction. The bending test showed that the flexural performance of the sample with 2 phr of TPP was improved by 38.8%. Therefore, this work provides a feasible method to prepare the thermoplastic epoxy resins and its fiber-reinforced composites with good mechanical properties.     

Miscibility,morphology and fracture toughness of epoxy resin/poly(vinyl acetate) blends

Diglycidylether of bisphenol A (DGEBA)/poly(vinyl acetate) (PVAc) blends cured with 4,4-diaminodiphenylmethane (DDM) were prepared. The miscibility and phase behavior were investigated by means of differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The study results indicate that the epoxy precursor (DGEBA)/PVAc blends are clearly miscible at the entire composition and theTg values experimentally obtained are in a good agreement with those predicted by Fox equation. Cured at elevated temperature, all the DDM-cured blends underwent phase separation and display two-phase morphology. When PVAc content is more than 10 wt%, the thermoplastics-modified resins began to show a co-continuous phase structure. It is the cocontinuous structure that leads to a significantly-improved toughness inK _ic. Morphologic investigation of the surfaces of fracture mechanic measurement specimens indicates that the toughening effect of the thermoplastics-modified epoxy resins may arise mainly from the ductile yielding of PVAc.