阻聚剂对酚醛环氧乙烯基酯的贮存及固化影响

通过正交实验法从4种酚醛环氧乙烯基酯树脂(NEVER)阻聚剂:氮杂环、吩噻嗪、对苯二酚、苄基三乙基氯化铵中确定了最佳复配阻聚剂。采用FTIR和DSC研究了含复配阻聚剂NEVER在热贮存下双键的变化及其固化反应动力学,并对固化后产物的不可溶分含量进行了测定。结果表明,最佳复配阻聚剂为氮杂环化合物和吩噻嗪,用量均占树脂质量的0.03%,此时NEVER在80℃下的贮存期可从11 h提高至60 h;树脂经80℃贮存50 h,总的C==C双键保留率达63.7%,说明选定的复配阻聚剂对NEVER具有良好的阻聚作用。固化的表观活化能从79.00 kJ/mol升高至87.44 kJ/mol,复配阻聚剂不影响最终产物的固化完全度。     

氨基-环氧基新型有机硅固化体系

以六甲基二硅氧烷、四甲氧基硅烷为原料合成了MQ树脂,然后与带环氧基的硅氧烷反应,合成了环氧基改性硅树脂;用γ-氨丙基三乙氧基硅烷合成氨基笼形倍半硅氧烷(氨基POSS)。并用红外光谱仪和X射线衍射仪表征了二者。将氨基POSS作为环氧基改性硅树脂的固化剂,利用多氨基和环氧基的开环加成反应组成一种新型有机硅固化体系。考察了环氧基改性硅树脂与氨基POSS的质量比对固化体系表干时间及固化物硬度的影响、固化物的耐热性。结果表明,环氧基改性硅树脂与氨基POSS的质量比为100∶1～150∶1时,表干时间较快,固化物表面光滑平整、硬度较好;环氧基改性硅树脂与氨基POSS的最佳质量比为100∶1;此固化体系室温下的操作时间较长,放置4周后黏度上升不超过15%;差热分析结果显示,固化物在40～300℃时的质量损失率为5%左右,分解温度在450℃左右,在681.28℃时的残留率仍有53%。     

新型耐热环氧单体的合成及性质研究

报道了一种含萘芳香酯型环氧单体二（4-（2,3-环氧丙氧基）苯甲酸）．2,7-萘4,4-二酯（P4）的合成及性质研究。利用FT-IR、1HNMR、质谱等分析测试方法对P4目标化合物的结构进行了表征。并用4,4．二氨基二苯基砜（DDS）和4,4-二氨基二苯基甲烷（DDM）两种芳香二胺固化剂对P4进行非等温固化研究。由结果可知,DDM／P4的固化峰温度为140℃,DDS／P4的固化峰温度为210℃,DDM能显著降低P4的固化温度。最后,通过对P4／DDM和环氧E20／DDM这两种固化物的热失重研究表明P4／DDM固化物具有较高的热稳定性。     

芳香酯基液晶环氧树脂的合成

以对羟基苯甲酸和对苯二酚为原料,用对甲苯磺酸共沸催化法合成对羟基苯甲酸对苯二酚酯;再由对羟基苯甲酸对苯二酚酯与4-溴环氧丁烷进行反应合成酚酯型液晶环氧物质4-(2-(环氧乙烷基)乙氧基)苯甲酸-4-(2-(环氧乙烷基)乙氧基)苯酚酯。研究该化合物与4,4’-二氨基二苯甲烷(DDM)固化反应的固化特性及固化物的力学性能,并对其结构以及固化行为和固化物的形态进行了表征。结果表明该液晶环氧树脂与DDM交联聚合的网络保持了较好的液晶织态,聚合物具有较好的综合性能。     

加成型液体硅橡胶的底涂剂及增粘剂(续)

介绍了含苯基或酯基的硅氧烷低聚物、含苯基的聚甲基氢硅氧烷、杂氮硅三环衍生物、含烯烃的酚类化合物或双（三甲氧硅丙基）富马酸酯与羟基封端的（CH3）2SiO/CH3（CH2=CH）SiO共聚物的复配物、含三羟甲基丙烷二烯丙酯与γ-环氧丙氧丙基及正硅酸乙酯的反应产物、含三烷氧基硅烷基和酯基的仲胺、四烷氧基硅烷与含乙烯基的硅氧烷低聚物及γ-甲基丙烯酰氧丙基三甲氧基硅烷的反应产物等几种加成型液体硅橡胶常用的增粘剂的结构特点,典型配方.     

高固体分涂料

0002180可在汽车板表面形成耐酸面漆层的高固体分涂料组合物:El?900832〔欧洲专利公开,英]/日本:Kansai paint Co·,Ltd4(Noura,KOhsuke等)尸1999.3.10一32页一JP97/277394(1997.10.9);IPCC09D143/04 一种有机溶剂型热固化高固体分()65%)涂料组合物含有(A)含梭基的化合物f酸值50~soomgKo川g,其中》20%(摩尔分数)的梭基是甲硅烷基化的梭基]、03))l种环氧化物[选自(B一l)含环氧基、经基和可水解烷氧基甲硅烷基的乙烯基聚合物、(B一2)>20%摩尔分数的经基为甲硅烷基化经基的B一l乙烯基聚合物和(B一3)数均相对分子质量<1000的环氧化合物l…     

PVC用环保型热稳定体系的复配研究

对酯基锡热稳定剂与硬脂酸类、环氧类以及烷基锡类等无毒或低毒热稳定剂进行了复配研究,用刚果红法和流变仪对复配体系进行了静态和动态热稳定性测试。静态热稳定性实验结果表明：硬脂酸钡、硬脂酸锌与酯基锡热稳定剂复配,体系的静态热稳定时间从32 min增至49 min;环氧助稳定剂与酯基锡有较好的协同效应;烷基锡与酯基锡复配,体系的热稳定时间由32 min增加到57 min。高于加工温度下的动态实验结果表明,酯基锡/烷基锡复合体系透明性良好,动态热稳定性好于钙锌复合热稳定剂体系。72 h紫外辐照老化实验结果表明,酯基锡/烷基锡复合体系有优异的耐紫外老化性能,老化后的拉伸强度保持率为98.14 %,断裂伸长率保持率为91.71 %。     

UV-PU双固化木器涂料的研制

介绍了以环氧丙烯酸酯、醇酸树脂和TDI加成物固化剂作为交联体系,制成了氨酯-环氧丙烯酸酯双固化的聚合物涂料。同时研究了环氧树脂、醇酸树脂、活性单体、固化剂以及组分配比对涂料性能的影响,并利用红外光谱、热重、DSC进行了表征,研究了该复合固化体系的反应特点。     

苄基二甲胺／双氰胺／环氧树脂体系固化反应和固化物性能的研究

本文应用ＩＲ，ＤＳＣ，介电和动态力学方法研究了温度和组成对苄基二甲胺／双氰胺／环氧树脂体系固化反应机理和固化物玻璃化温度的影响，结果表明，在１００℃和１７０℃均不利于醚化反应，体系中叔胺和环氧基含量越少，越不利于醚化反应，在１００℃时环氧基只与伯氨基进行加成反应，但在１４０℃或１７０℃，除了环氧基与氨基的加成反应外，还包括氰基与体系中羟基和环氧基反应形成亚氨醚键，然后双重排反应得到含酰胺键的化合物     

杂臂星型低聚物的合成及其增韧环氧树脂研究

以六氯环三磷腈和对羟基苯甲醛反应合成了六(对醛基苯氧基)环三磷腈,再将其与油胺反应合成了星型化合物,将该星型化合物的亚胺还原为仲胺,与环氧低聚物反应得到了一种杂臂星型低聚物。采用红外光谱和核磁共振光谱表征了产物的结构。将该产物加入到环氧-酸酐体系中,通过示差扫描量热分析、热重分析及动态热力学分析考察了其对环氧体系热固化过程的影响,以及不同添加量对环氧固化物力学性能及热性能的影响。结果表明,杂臂星型低聚物的加入不会显著影响环氧树脂的固化过程以及固化物的玻璃化转变温度。加入杂臂星型低聚物可显著提升环氧树脂的耐冲击性,当添加质量分数为5%时,固化物的冲击强度最佳,较纯环氧固化物提升约150%,且材料的拉伸强度、热稳定性和耐水性均有一定程度的提高。     

Thermoreversible rheological responses of biscarbamates and tricarbamates in uncured epoxy composite pastes caused by their self‐assembly in an epoxy matrix

We investigated the rheological behaviors of diglycidyl ether of bisphenol A (epoxy resin) composite pastes with fumed SiO₂, biscarbamates, and tricarbamates with the same terminal alkyl chains of C₁₆, respectively. The rheological measurement results show that the rheological responses of both carbamates in the epoxy composite pastes were stronger than that of fumed silica at the same concentrations, especially at low concentrations, and the rheological behaviors of the epoxy composites with them were thermally reversible and concentration dependent. IR, thermal, differential scanning calorimetry, and polarized microscopic analyses demonstrated that their different excellent rheological responses in epoxy composite pastes came from their different self‐assemblies in the epoxy matrix, which were caused by the different intermolecular interactions, mainly including hydrogen‐bonding and van de Waals interactions, and the intermolecular interactions for carbamates were closely related to their molecular structures. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46032.     

Effect of processing conditions on physical properties of 3‐aminophenoxyphthalonitrile/epoxy laminates

To develop high performances of polymer composite laminates, differential scanning calorimetry and dynamic rheological analysis studies were conducted to show curing behaviors of 3‐aminophenoxyphthalonitrile/epoxy resin (3‐APN/EP) matrix and define cure parameters of manufacturing processes. Glass fiber reinforced 3‐APN/EP (GF/3‐APN/EP) composite laminates were successfully prepared through different processing conditions with three parameters such as pressures, temperatures, and time. Based on flexure tests, dynamic mechanical analysis, thermal gravimetric analysis, and scanning electron microscope, the complementary catalytic effect of the three processing parameters is investigated by studying mechanical behavior, thermomechanical behavior, thermal behavior, and fracture morphology of GF/3‐APN/EP laminates. The 50/50 GF/3‐APN/EP laminates showed a significant improvement in flexural strength, glass transition temperature (T_g), and thermal stability with favorable processing parameters. It was also found that the T_g and thermal stability were significantly improved by the postheated treatment method. The effect of manufacturing process provides a new and simple route for the polymer–matrix composites application, which indicates that the composites can be manufactured at low temperatures. But, they can be used in a high temperature environment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39746.     

Grafting of Epoxy Resin on Surface-modified Poly(tetrafluoroethylene) Films

An epoxy/PTFE composite was prepared by curing the epoxy resin on the surface-modified PTFE film. Surface modification of PTFE films was carried out via argon plasma pretreatment, followed by UV-induced graft copolymerization with glycidyl methacrylate (GMA). The film composite achieved a 90°-peel adhesion strength above 15 N/cm. The strong adhesion of the epoxy resin to PTFE arose from the fact that the epoxide groups of the grafted GMA chains were cured into the epoxy resin matrix to give rise to a highly crosslinked interphase, as well as the fact that the GMA chains were covalently tethered on the PTFE film surface. Delamination of the composite resulted in cohesive failure inside the PTFE film and gave rise to an epoxy resin surface with a covalently-adhered fluoropolymer layer. The surface composition and microstructures of the GMA graft-copolymerized PTFE (GMA-g-PTFE) films and those of the delaminated epoxy resin and PTFE film surfaces were characterized by X-ray photoelectron spectroscopy (XPS), water contact angle and scanning electron microscope (SEM) measurements. The delaminated epoxy resin surfaces were highly hydrophobic, having water contact angles of about 140°C. The value is higher than that of the pristine PTFE film surface of about 110°. The epoxy resin samples obtained from delamination of the epoxy/GMA-g-PTFE composites showed a lower rate of moisture sorption. All the fluorinated epoxy resin surfaces exhibited rather good stability when subjected to the Level 1 hydrothermal reliability tests.     

Grafting of Epoxy Resin on Surface-modified Poly(tetrafluoroethylene) Films

An epoxy/PTFE composite was prepared by curing the epoxy resin on the surface-modified PTFE film. Surface modification of PTFE films was carried out via argon plasma pretreatment, followed by UV-induced graft copolymerization with glycidyl methacrylate (GMA). The film composite achieved a 90°-peel adhesion strength above 15 N/cm. The strong adhesion of the epoxy resin to PTFE arose from the fact that the epoxide groups of the grafted GMA chains were cured into the epoxy resin matrix to give rise to a highly crosslinked interphase, as well as the fact that the GMA chains were covalently tethered on the PTFE film surface. Delamination of the composite resulted in cohesive failure inside the PTFE film and gave rise to an epoxy resin surface with a covalently-adhered fluoropolymer layer. The surface composition and microstructures of the GMA graft-copolymerized PTFE (GMA-g-PTFE) films and those of the delaminated epoxy resin and PTFE film surfaces were characterized by X-ray photoelectron spectroscopy (XPS), water contact angle and scanning electron microscope (SEM) measurements. The delaminated epoxy resin surfaces were highly hydrophobic, having water contact angles of about 140°C. The value is higher than that of the pristine PTFE film surface of about 110°. The epoxy resin samples obtained from delamination of the epoxy/GMA-g-PTFE composites showed a lower rate of moisture sorption. All the fluorinated epoxy resin surfaces exhibited rather good stability when subjected to the Level 1 hydrothermal reliability tests.     

粒子分散性对环氧树脂/纳米SiO2材料性能的影响

通过原位分散聚合法制得了环氧树脂／纳米SiO2复合材料。采用超声波和偶联剂改善了纳米SiO2在基体中的分散性，利用拉伸实验、冲击实验、扫描电子显微镜、热重法等方法研究了粒子分散性对复合材料结构和性能的影响。结果表明：超声波和偶联剂都能使纳米SiO2均匀地分散在环氧树脂基体中，有效地增加复合材料的力学强度及韧性，并能提高材料的耐热性。对于提高纳米SiO2在环氧树脂中的分散均匀性，超声波的作用优于偶联剂。     

Mechanical properties and fracture behaviors of epoxy composites with phase‐separation formed liquid rubber and preformed powdered rubber nanoparticles: A comparative study

Epoxy composites filled with phase‐separation formed submicron liquid rubber (LR) and preformed nanoscale powdered rubber (PR) particles were prepared at different filler loading levels. The effect of filler loading and type on the rheological properties of liquid epoxy resin suspensions and the thermal and mechanical properties of the cured composites as well as the relative fracture behaviors are systematically investigated. Almost unchanged tensile yield strength of the cured epoxy/PR composites is observed in the tensile test compared with that of the neat epoxy; while the strength of the cured epoxy/LR composites shows a maximum value at ∼4.5 wt% and significantly decreases with increasing LR content. The glass transition temperature (T_g) of the cured PR/epoxy has shifted to the higher temperature in the dynamic mechanical thermal analysis compared with that of the cured pure epoxy and epoxy/LR composites. Furthermore, the presence of LR results in highly improved critical stress intensity factor (K_IC) of epoxy resin compared with the corresponding PR nanoparticles. In particular, the PR and LR particles at 9.2 wt% loading produce about 69 and 118% improvement in K_IC of the epoxy composites, respectively. The fracture surface and damage zone analysis demonstrate that these two types of rubber particles induce different degrees of local plastic deformation of matrix initiated by their debonding/cavitation, which was also quantified and correlated with the fracture toughness of the two epoxy/rubber systems. POLYM. COMPOS., 36:785–799, 2015. © 2014 Society of Plastics Engineers     

环氧树脂对PA6/EPDM-g-MAH共混体系性能的影响

将两种不同型号的环氧树脂（EP(903)、EP(619D)）分别与PA6/EPDM-MA体系进行共混,制备了PA6/EPDM-MA/EP三元共混物。通过力学测试、动态流变(DMA)、差示扫描量热法（DSC）研究了不同EP添加量和环氧当量对PA6/EPDM-MA/EP共混体系性能的影响。实验结果表明：添加EP可以提高PA6/EPDM-MA共混物的拉伸强度,缺口冲击强度,并随着EP含量的增加而增加;而PA6/EPDM-MA/EP三元共混体系的动态储能模量（G′）,复合黏度（η*）随着EP含量的增加而增大,损耗因子（tanδ）减小;结晶度比未加环氧的共混物的结晶度稍高,并且随着环氧含量增加先增加后降低。此外,添加EP(903)的共混物各种性能变化比EP(619D)快。     

Comparison of the effect of epoxy microspheres on the thermomechanical and rheological properties of an epoxy resin system

The rheological and thermomechanical behaviors of toughened epoxy resins filled with thermosetting microsized spherical particles were investigated. Two epoxy systems were used to prepare microspheres: a Bisphenol A‐type resin (EPON825) cured with 2,4‐diaminotoluene and a Bisphenol F‐based epoxy resin (PY306) crosslinked with diethyltoluenediamine. Both systems of microspheres were synthesized through dispersion polymerization and differed to each other in size, as evidenced by morphological analysis. These microparticles were blended, in different weight percents (10 and 20 wt%), with a matrix consisting of diglycidyl ether of Bisphenol A (EPON828) and 3,3′‐diaminodiphenylsulphone (3,3′DDS). Rheological behavior of the prepared blends was preliminarily studied. After cure, the dynamic‐mechanical properties of the composites were also investigated. Results indicated that the reactivity of the uncured blends, as well as the viscoelastic properties of crosslinked systems, are influenced not only by the nature and the amount of the microparticles introduced, but also, in a significant way, by their size. POLYM. ENG. SCI. 46:1739–1747, 2006. © 2006 Society of Plastics Engineers.     

Correlation between viscoelastic behavior and cooling stresses in a cured epoxy resin system

This work deals with the study of the rheological behavior of an epoxy system subjected to three cooling processes referred to as the normal, air‐, and water‐cooling processes. The system was set up by a difunctional epoxy resin (DGEBA) mixed with a tetrafunctional diamine (mPDA) in stoichiometric proportions. Different samples of (1) neat and cured polymers and (2) alumina—epoxy composites were prepared. The first part of this work was devoted to optimizing the cure cycle of the neat samples using differential scanning calorimetry and rheometry. The best cure cycle is based on a first heat step at 110°C during 10 min followed by a crosslinking stage of 75 min at 180°C. In the second part of the study the influence of the cooling cycle on the thermomechanical behavior of polymer and composite samples was investigated. Measurement of loss modulus, G″, and loss factor, tan δ, versus temperature showed that an intermediate relaxation α′ peak arose between the main and secondary relaxations (resp. α and β). The position and amplitude of the α′ peak increased with the cooling rate. This rheological phenomenon is related to the presence of nonequilibrium stresses frozen in the sample during cooling. The effect of thermal aging on the α′ peak also is reported. Our work also showed the presence of an α′ peak for the composites. However, the amplitude of this peak was more pronounced in the composites because of additional stresses induced by the difference between the resin and the ceramic in thermal expansion coefficients. We showed that a calculation based on a thermoelastic model was useful for qualitative comparison of rheological data on the influence of the cooling process. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 679–690, 2006     

Preparation of Epoxy Resin Based on 1,5-Naphthalenediol and Its Application in Carbon Fiber-Reinforced Composites

A series of new epoxy resin base on 1,5-naphthalenediol were prepared to produce the heat-resistant carbon fiber-reinforced composites. The structures of the epoxy resins were characterized by Fourier Transform Infrared (FTIR) spectroscopy and Gel Permeation Chromatography (GPC) analyses. Dynamic curing behavior was investigated using Differential Scanning Calorimetry (DSC). The physical properties of the cured polymers were evaluated with Dynamic Thermal Mechanical Analyses (DMTA) and Thermogravimetric Analyses (TGA). The results showed that the cured polymer exhibited a higher glass transition temperature (T_g) of 251.1°C and better thermal stability. Such properties make the resin highly promising for heat-resistant composite applications.