玻璃纤维增强环氧树脂复合材料的力学性能研究

本文以环氧树脂为基体,经改性过的短切玻璃纤维为增强材料,制备了玻璃纤维增强环氧树脂(GF/EP)复合材料。探究了玻璃纤维与环氧树脂配比、固化条件对GF/EP复合材料力学性能的影响。结果表明:当玻纤用量为20%、固化温度为120℃、固化时间为3.0 h时制备的GF/EP复合材料拉伸强度约为38.52 MPa、冲击强度约为6.46k J/m2;GF/EP复合材料经60℃、5%的食盐水浸泡48 h后力学性能下降,SEM显示纤维与树脂的粘结界面经腐蚀后被破坏。     

聚三唑树脂的催化固化及其复合材料制备与性能

为了降低固化温度,简化固化工艺,在聚三唑树脂(PTA)体系中加入三苯基磷溴化亚铜作为催化剂,根据催化剂的用量与凝胶时间的关系,确定催化剂用量为最少单体摩尔量的3‰。在催化条件下,按照50℃/6h+100℃/2h+150℃/2h的固化程序模压制备复合材料(C-PTA/T300B),研究了催化剂对复合材料玻璃化转变温度(Tg)、热稳定性(Td5)和力学性能的影响。结果表明,与未催化复合材料(PTA/T300B)相比,在力学性能保持不变的前提下,C-PTA-T300B复合材料的固化温度降低了30℃,后处理工艺得到极大简化;Tg提高了21℃;空气中Td5提高了10℃,氮气中Td5提高了5℃。     

端脂肪氨基聚醚/环氧树脂胶粘剂的固化工艺研究

以端脂肪氨基聚醚(AATPE)作为环氧树脂(EP)的固化剂,制备出一种高强度、高韧性的EP胶粘剂。采用动态差示扫描量热(DSC)法和凝胶化理论模型研究了AATPE/EP胶粘剂体系的固化反应特点,并对其固化工艺进行了优化。结果表明:AATPE/EP体系的最佳固化工艺条件为"50℃/6 h→100℃/2 h";在最佳固化工艺条件下制备的固化产物,其固化度为97.14%,并且其力学性能优异。     

环氧灌封料固化反应动力学及其性能研究

采用非等温示差扫描量热法(DSC)研究了环氧树脂(E-51)/甲基四氢苯酐/DMP-30/球形SiO2体系的固化反应动力学,采用Kissinger法和Crane公式对体系的DSC数据进行了处理,获得了固化反应动力学参数,确定了固化工艺。同时通过力学性能和热性能测试研究了球形SiO2添加量对复合材料性能的影响。结果表明,SiO2质量分数为10%的体系其起始固化温度为109.7℃,峰顶固化温度为134.8℃,终止固化温度为154.3℃;较好的固化工艺为100℃/2 h+140℃/2 h+160℃/2 h。该体系反应级数n=0.917,表观活化能Ea=78.52 kJ/mol。当SiO2添加量为30%时,其弯曲强度达到最大值97 MPa,同时热分解温度达到最大值332℃,试样热膨胀系数也明显降低。     

环氧树脂/环氧液晶/蒙脱土纳米复合材料研究

采用液晶环氧预聚物(PHQEP)与有机蒙脱土(OMMT)共混改性环氧树脂制备三元共混体系的环氧基复合材料。用X射线衍射法(XRD)测试了有机化蒙脱土在被插层前后片层间距的变化,通过DSC、TGA及SEM等对PHQEP/OMMT增韧改性环氧树脂固化体系的力学性能,热性能及微观相态结构进行了研究。结果表明:当PHQEP质量分数为5%,添加1.5%的有机蒙脱土可以使环氧树脂的冲击强度达到最大值23.43 kJ/m2,比纯环氧树脂提高2倍左右,玻璃化转变温度及5%热分解温度比纯环氧树脂分别高出15℃和27℃。PHQEP与OMMT的加入使纳米复合材料的力学性能和热性能得到明显提高。     

一种无色透明环氧树脂复合材料的制备及其性能研究

本文选择适合无色透明环氧树脂/酸酐树脂的促进剂,对无色透明环氧树脂体系的流变性、凝胶时间、热性能等进行分析,确定了树脂的固化工艺。采用热熔胶膜法制备玻璃布预浸料,用模压法制备层合板,对预浸料和复合材料的物理性能、力学性能、耐热性和透光率进行测试,结果表明,无色透明环氧树脂预浸料在135℃/2h完全固化,复合材料层压板力学性能耐热性和透光率较好。     

碱催化2步法制备SiO2/环氧树脂杂化材料的研究

以氨水为催化剂,以二氨基二苯砜(DDS)为固化剂,采用2步法制备二氧化硅/环氧树脂(SiO2/环氧树脂)杂化材料.分析了正硅酸乙酯(TEOS)用量对SiO2/环氧树脂杂化材料化学结构、力学性能和热性能的影响.结果表明,TEOS的加入没有改变固化物的化学结构.拉伸和弯曲模量均随TEOS用量增加先增加后降低,当TEOS质量...     

丁腈橡胶/AG-80/E-44环氧树脂复合材料的固化行为研究

采用示差扫描量热法(DSC)对丁腈橡胶/AG-80/E-44环氧树脂复合材料的固化行为进行了研究。研究了反应温度对环氧树脂复合材料黏度的影响、凝胶时间随温度变化曲线,热失重法(TGA)测试了环氧树脂复合材料的耐热性能,计算了环氧树脂固化反应的反应焓、表观活化能,最后推导出固化反应条件。结果表明,随着温度升高,丁腈橡胶/AG-80/E-44环氧树脂复合材料的黏度降低,确定40℃为最佳操作温度,环氧树脂复合材料的耐热性良好。通过凝胶时间随温度变化曲线测试,确定了2步固化步骤,先低温抽真空,再高温固化。环氧树脂复合材料固化反应的表观活化能E_a为45.52kJ/mol,频率因子A为2.16×10~5/s,反应级数n为0.9,固化工艺为:80℃/2h+120℃/2h+200℃/2h。     

三乙烯四胺固化有机蒙脱土/环氧树脂复合体系的研究

以三乙烯四胺作为EP(环氧树脂)的常温固化剂制备EP/OMMT(有机蒙脱土)/三乙烯四胺纳米复合材料。采用X射线衍射(XRD)法,差示扫描量热(DSC)法等手段研究了不同配方对EP/OMMT/三乙烯四胺固化体系的凝胶时间、力学性能、热性能及OMMT的插层剥离行为等影响。结果表明:对EP/OMMT/三乙烯四胺复合材料而言,90~120℃固化体系的OMMT剥离与插层效果优于室温固化体系;当固化温度为120℃时,EP/OMMT/三乙烯四胺复合材料的耐湿热性能和弯曲强度均优于常温固化体系;EP/OMMT/三乙烯四胺复合材料经常温固化24 h后,其冲击强度比纯EP体系提高了7%~12%。     

氰酸酯改性环氧树脂复合材料的研究

采用双酚A型二氰酸酯对环氧树脂E51进行改性,并制备出玻璃纤维增强复合材料。通过傅里叶红外光谱(FTIR)、动态热力学分析(DMA)对不同质量比的环氧树脂/氰酸酯的共固化产物结构特征以及复合材料的玻璃化转变温度进行了研究,同时测定并讨论了对复合材料的拉伸性能、弯曲性能、吸湿性能的影响。结果表明,在环氧树脂和氰酸酯共固化体系中,随着氰酸酯含量的增加,固化物中三嗪环的相对含量增加,噁唑烷酮的相对含量降低。当环氧树脂/氰酸酯质量比为50/50时,复合材料的玻璃化转变温度为215.6℃,与未改性相比提高了49.7℃;650h后吸水率显著降低,仅为0.69%;但拉伸强度和弯曲强度略有降低。扫描电镜(SEM)分析表明,加入氰酸酯后,增加了复合材料的残余应力,使复合材料呈现出脆性断裂。     

Effects of spherical silica on the properties of an epoxy resin system

The spherical silica powders were prepared by using an oxygen–acetylene flame method. After spheroidization, a scanning electron microscope investigation revealed that the spheroidization efficiency of the powder was nearly 100%, XRD patterns indicated that the raw crystal silica became amorphous silica. In this study, composites of spherical silica and an epoxy resin were prepared with a homogenizer, followed by a stepwise thermal curing process. The thermal stability and thermal degradation behavior of the composites were studied by a thermogravimetric analyzer. Meanwhile, the effects of spherical silica powder on dynamic mechanical, coefficient of thermal expansion, and mechanical properties of epoxy/silica composites were also investigated. The initial decomposition temperature and mechanical properties increased significantly after adding the spherical silica into the composite. The maximum properties of thermal stability and mechanical properties were observed when spherical silica accounted for 30% of the system. The thermal expansion had been significantly reduced by the addition of silica. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

高性能室温固化环氧结构胶的制备与研究

为了改善环氧固化物的韧性,又保持其热稳定性及提高其抗冲击性能,采用超细全硫化羧基丁腈橡胶粒子改性环氧树指技术,并辅以玻璃微珠,球型硅微粉,ACR丙烯酸酯橡胶微球等抗冲剂填充,制备出一款高性能室温固化环氧结构胶.实验中采用高速搅拌球磨法在环氧树脂中分散超细全硫化羧基丁腈橡胶粒子,辅以填充物,制备的环氧树脂结构胶剪切冲击强...     

Synthesis of epoxy resin–silica nanocomposites provided from perhydropolysilazane as a curing reagent and the precursor of silica domain

Epoxy resin–silica nanocomposites with spherical silica domains with 29.0 nm in diameter in an epoxy resin matrix were synthesized from Bisphenol‐A type epoxide monomer, 2,2‐bis(4‐glycidyloxyphenyl)propane (DGEBA), and perhydropolysilazane (PHPS, ? [Si₂? NH]_n? ). The volume fraction of silica domain in the composite varied from 5.4 to 37.8 vol % by varying the feed ratio of PHPS to the epoxide monomer. The reaction mechanism of epoxy group and PHPS was investigated by using glycidyl methacrylate as a model compound of the epoxy monomer by ¹H‐nucular magnetic resonance and Fourier transform infrared spectrometry. Ammonia gas provided by the decomposition of PHPS with moisture converted PHPS to silica and cured the epoxy monomer. The curing of epoxy monomer preferably proceeded than the conversion of silica. The addition of 1,4‐diaminobutane drastically accelerated the rate of curing; white and hard epoxy resin–silica nanocomposites were obtained. The good thermal stability of the composite prepared with DGEBA/PHPS/1,4‐diaminobutane was observed by thermogravimetric analysis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation of epoxy resin/silica hybrid composites for epoxy molding compounds

Phenolic novolac/silica and cresol novolac epoxy/silica hybrids were prepared through in situ sol‐gel reaction of tetraethoxysilane (TEOS). The formed hybrids were utilized as a curing agent and an epoxy resin in epoxy curing compositions, respectively. Via the two‐step preparation route, the resulting epoxy resin/silica hybrid nanocomposites exhibited good thermal stability, high glass transition temperatures, and low coefficients of thermal expansion. High condensation degree of the condensed silica was observed with a high content of siloxane bridges, p > 85%, measured by ²⁹Si NMR. The two‐step route also provides feasibility of preparation of epoxy resin/silica hybrid nanocomposites compatible with the current processes of manufacturing of epoxy molding compounds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4047–4053, 2003     

环氧树脂聚酰胺网络体系性能研究

用红外光谱法表征了4种聚酰胺固化剂与环氧树脂按等当量配比,在一定条件下的固化反应过程。DSC法测定了其固化反应活性。桐马聚酰胺/环氧树脂固化体系较聚酰胺650/环氧树脂固化体系的固化活性大大提高,同时测定了该固化产物的热失重(TG)及玻璃化温度(Tg),对该固化物的热稳定性进行了评价,还测定了不同固化时间的剪切强度以研究其动态力学性能,从浇铸体的冲击强度方面比较其韧性。综合比较分析了聚酰胺固化剂与环氧树脂固化体系的力学性能、耐热性、电绝缘性等。结果表明:桐马聚酰胺Ⅲ型固化剂具有黏度低、粘接强度大、耐热性好、力学性能优等优点。     

Phenol novolac/poly(4- hydroxyphenylmaleimide) blend hardeners for DGEBA-type epoxy resin

Phenol novolac/poly (4-hydroxyphenylmaleimide) (PHPMI) blends were used as an epoxy resin hardener. The curing behavior of the above system and the thermal and mechanical properties of the cured epoxy resin were studied. It was not necessary to use a curing accelerator for this system, because PHPMI caused acceleration of the curing reaction. The curing mechanism of this system was investigated by using model compounds. Test pieces from the neat resins and the glass fiber reinforced resins were evaluated in terms of thermal and mechanical properties, respectively. It was found that heat resistance and mechanical properties were improved by increasing the amount of PHPMI in the hardener.     

硅烷单体改性环氧树脂的固化及性能

分别用苯基三甲氧基硅烷(PTMS)和3-缩水甘油醚氧丙基三甲氧基硅烷(KH560)单体对环氧树脂进行了化学改性,通过红外(FT-IR)、核磁(1H NMR)对其化学结构进行了表征。以聚酰胺650为固化剂,用差示扫描量热仪(DSC)研究了固化物的固化动力学。此外还研究了涂膜的热失质量(TGA)、吸水率、附着力等性能。结果表明:苯基三甲氧基硅烷和3-缩水甘油醚氧丙基三甲氧基硅烷接枝上环氧树脂,与纯环氧树脂相比,改性后的树脂具有更好的热稳定性和更低的吸水率。改性环氧树脂固化后形成两面性质不同的涂层,与底材接触的涂层底面保留了环氧树脂原有的附着力,而涂层表面则具有高憎水性,起到防腐等作用。     

环氧树脂/石英纤维透波复合材料制备

为改善环氧树脂的介电性能及提升石英纤维的界面性能,使用缩水甘油醚基笼型倍半硅氧烷(G-POSS)和γ-氨丙基三乙氧基硅烷(KH-550)分别对环氧树脂和石英纤维进行改性.利用差示扫描量热法研究改性后环氧树脂的固化过程,并通过外推法确定了其固化工艺,根据固化工艺制备环氧树脂/石英纤维复合材料,分别对该复合材料的热稳定性、...     

聚氨酯嵌段改性环氧树脂的合成及性能

通过两步法在环氧树脂主链中成功引入了聚氨酯链段,合成了新型环氧树脂。采用傅立叶变换红外光谱仪、热失重分析仪、差示扫描量热仪等对其进行了结构、热学和力学性能表征。通过合成条件优化及固化过程的研究,得到了最佳反应条件:第一步反应为50℃下反应1 h,第二步反应为70℃下反应1 h,固化条件为110℃反应1 h,升高至140℃后反应2 h,继续升高至160℃后再反应1 h。通过对固化后环氧树脂的热性能及拉伸性能的研究发现,聚氨酯链段的引入可将环氧树脂的断裂伸长率提高至36.7%~130.1%,但是却在一定程度上降低了其热稳定性和拉伸强度。     

热固性环氧树脂改性沥青粘结剂的性能研究

以环氧树脂为沥青改性剂制备了热固性环氧沥青粘结剂。利用示差扫描量热仪(DSC)、动态热力学分析(DMA)、万能材料试验机和布氏旋转粘度计研究了环氧树脂改性沥青粘结剂的等温和非等温固化反应、玻璃化转变温度(Tg)、阻尼行为、力学性能和粘温特性。结果表明,环氧沥青粘结剂等温固化反应属于自催化反应,沥青的加入大大地降低了环氧树脂的固化热,其固化后只有1个Tg(远高于纯沥青的Tg),说明环氧树脂和沥青有很好的相容性。环氧沥青粘结剂还具有优异的阻尼行为,很高的拉伸强度和韧性。