双酚F/间苯二酚共聚型环氧树脂

采用间苯二酚、双酚F与环氧氯丙烷共聚合成一种高性能的环氧树脂,研究了不同反应温度、反应时间、双酚F/间苯二酚比例等条件对共聚环氧树脂结构材料性能的影响,确定了合成条件。结果表明所制备的双酚F/间苯二酚共聚型环氧树脂粘度比单纯双酚F环氧树脂低,其热固化结构材料的韧性、耐热性和拉伸强度较纯双酚F和间苯二酚型环氧树脂有明显提高。其最佳合成条件为:醚化温度为80℃,醚化时间5h,加碱闭环温度为60℃,加碱速度为4g/10min。间苯二酚与双酚F质量为20∶80时共聚树脂的综合性能最佳。其粘度为2 1Pa·s,比单纯的双酚F环氧树脂下降了42%;玻璃化温度为165℃,比纯双酚F环氧树脂提高了20℃;拉伸强度为102 3MPa,比纯双酚F环氧树脂提高了27%;弯曲强度为113 6MPa,比单纯的双酚F环氧树脂下降了18%。     

RTM用中温固化环氧树脂基体的研究

在双酚F树脂中分别加入不同质量的711和TDE-85环氧树脂制备了6种环氧树脂体系,并采用聚醚胺和脂环胺复合固化剂固化,对各体系的粘度、固化行为、耐热性及力学性能进行了测试。结果表明,711环氧树脂具有比TDE-85更高的反应活性。在80 g双酚F树脂中加入20 g TDE-85环氧制备的体系具有最佳的综合性能,30℃下的适用期(粘度500 mPa·s)为120 min,玻璃化转变温度102℃,常温下固化物拉伸强度为78.6 MPa,有望用于多种复合材料的RTM成型。     

有机硅磷杂化改进环氧树脂耐热性、韧性和阻燃性的研究

将聚甲基三乙氧基硅烷（PTS）与一种合成的含磷硅烷偶联剂以一定配比进行反应,所得改性剂添加到双酚A环氧树脂E51/酚醛树脂固化体系中,对改性环氧树脂固化产物的玻璃化转变温度、热失重、冲击强度、拉伸强度、极限氧指数进行了测试,并对固化产物的表面形貌进行了SEM观察。结果表明,在保持拉伸强度基本不变的同时,改性环氧树脂固化物的玻璃化转变温度、高温热稳定性、冲击强度、极限氧指数均有不同程度提高,使改性环氧树脂的性能得到综合提升。     

双氰胺固化双酚F/间苯二酚共聚型环氧树脂的研究

为提高双酚F环氧树脂的综合性能,以双酚F、间苯二酚与环氧氯丙烷反应制得双酚F/间苯二酚共聚型环氧树脂。通过差示扫描量热法(DSC)研究了2-乙基-4-甲基咪唑对双氰胺-双酚F/间苯二酚共聚型环氧树脂体系固化反应的促进作用,并系统地探讨了固化体系及固化条件对固化物性能的影响。结果显示,其最佳固化工艺条件是:间苯二酚与双酚F质量比为20∶80,双氰胺质量分数为6%,2-乙基-4-甲基咪唑质量分数为4%,固化温度为110℃,固化时间为3 h。     

环氧-环硫树脂/凹凸棒土复合体系性能

采用双酚A型E-51环氧树脂与硫脲为原料,制备了环氧-环硫树脂(EP-ES)。通过IR分析确定合成产物结构中有环硫基团存在。对合成产物固化过程的DSC测试,表明环氧-环硫树脂具有比环氧树脂更低的固化温度及更少的固化反应热。并通过超声分散和溶液共混法制备了环氧-环硫树脂/有机化凹凸棒土(EP-ES/OAT)复合材料,对该复合材料的形态结构和性能进行力学性能、SEM、DMA和TGA测试。结果表明:与EP-ES树脂相比,EP-ES/OAT复合材料的力学性能、玻璃化温度以及耐热性能均有不同程度的提高。     

生物质环氧树脂的研究进展

综述了不同类型的生物质环氧树脂(包括木质素环氧树脂、植物油环氧树脂、天然酚环氧树脂以及其他生物质环氧树脂等)的研究进展。对上述各种生物质环氧树脂的制备方法、合成条件、反应原理等进行了概述,阐述了生物质原料中碳碳双键环氧化的转化率以及生物质环氧树脂固化的活化能等,分析了生物质环氧树脂的性能如黏度、玻璃化转变温度、拉伸强度、断裂伸长率、剥离强度、剪切强度、硬度、介电常数、极限氧指数、残炭率等,并与石油基的双酚A型环氧树脂和商业化的脂环式环氧树脂ERL-4221的性能进行了比较。此外,还提出了生物质环氧树脂的研究建议,为今后合成高性能、低成本和附加值高的生物质环氧树脂提供相应参考。     

1种新型的环氧树脂型高强度结构胶

该发明是1种新型的环氧树脂型高强度结构胶,由2种组分组成,其中甲组分由环硫-环氧活性稀释剂与环氧树脂和／或环硫．环氧复合树脂组成,乙组分为固化剂或固化剂与固化促进剂的混合物。这种发明的高强度结构胶与相应的环氧树脂结构胶相比,具有更高的剪切强度、剥离强度和更快的固化速度。     

二氯二苯基硅烷改性环氧树脂

重庆大学的章华中等人将二氯二苯基硅烷与双酚A型环氧树脂在丙酮中进行反应,并用三乙胺吸收氯化氢;改性环氧树脂用酸酐类固化剂固化。当二氯二苯基硅烷的用量为5．9份时,改性环氧树脂的拉伸强度达到了68MPa,断裂伸长率为7．6％,冲击强度达13kJ／m^2,玻璃化转变温度达146．56℃;     

硅磷杂化物/环氧树脂固化物的性能研究

以γ-环氧丙氧基三甲氧基硅烷(KH-560)与磷酸反应合成了一种含磷硅烷偶联剂,将这种含磷硅烷偶联剂与硅溶胶按一定配比进行水解缩聚反应,得到一种硅磷杂化物,将该硅磷杂化物引入到双酚A环氧树脂(E-51),以4,4′-二氨基二苯基甲烷为固化剂,制备了硅磷杂化物/环氧树脂固化物。对该固化物的玻璃化转变温度、热失重、拉伸强度、极限氧指数(LOI)进行了测试。结果表明,该固化物玻璃化转变温度,700℃残炭量以及LOI均比纯环氧树脂固化物高,拉伸强度却下降较少。当硅磷杂化物的添加量占环氧树脂质量的50%时,该固化物的玻璃化转变温度可以达到178℃,极限氧指数可以达到28.2,与纯环氧树脂固化物相比,分别提高了18℃和25%。与纯环氧树脂固化物相比,该硅磷杂化物/环氧树脂固化物具有较好的阻燃性及热稳定性。     

甲基纳迪克酸酐固化环氧树脂的动力学研究

采用差示扫描量热法（DSC）,研究了以2-乙基-4-甲基咪唑为促进剂,甲基纳迪克酸酐固化双酚A型环氧树脂的固化行为特征。以固化反应焓和玻璃化温度两种参数,确定酸酐固化环氧树脂体系的最佳酐基系数,实验确定最佳酐基系数为0.90。依据四种不同升温扫描速率提供的数据,建立了该体系动力学方程并计算出固化反应级数。应用T-β外推法计算出甲基纳迪克酸酐固化双酚A型环氧树脂的固化工艺,即130℃3 h+160℃2 h。     

Synthesis and characterization of diphenylsilanediol modified epoxy resin and curing agent

A series of diphenylsilanediol modified epoxy resins and novel curing agents were synthesized. The modified epoxy resins were cured with regular curing agent diethylenetriamine (DETA); the curing agents were applied to cure unmodified diglycidyl ether of bisphenol A epoxy resin (DGEBA). The heat resistance, mechanical property, and toughness of all the curing products were investigated. The results showed that the application of modified resin and newly synthesized curing agents leads to curing products with lower thermal decomposition rate and only slightly decreased glass transition temperature (T_g), as well as improved tensile modulus and tensile strength. In particular, products cured with newly synthesized curing agents showed higher corresponding temperature to the maximum thermal decomposition rate, comparing with products of DGEBA cured by DETA. Scanning electron microscopy micro images proved that a ductile fracture happened on the cross sections of curing products obtained from modified epoxy resins and newly synthesized curing agents, indicating an effective toughening effect of silicon–oxygen bond.     

Prospects in the application of a frontally curable epoxy resin for cured-in-place-pipe rehabilitation

Photocurable acrylates and vinyl esters are among the most commonly used resins in cured-in-place-pipe (CIPP) rehabilitation technology, as they impart excellent thermomechanical properties in composite pipes. In the quest for achieving a higher energy efficiency of the photo-curing process in CIPP, the frontal polymerization technique is a viable alternative that requires a lower irradiation dosage coupled with exceptionally high curing speeds and depths. Herein, for the first time, we report the application of frontal polymerization in the rehabilitation of underground pipes using a newly developed frontally curable epoxy-based resin (Trelleborg Self-Curing*). The neat resin is characterized for degree of cure, glass transition temperature, and mechanical properties via FTIR, DMA, and tensile tests, respectively. In a comprehensive way, the properties are benchmarked against commercially available acrylate (Trelleborg Light Cure*) and vinyl ester (Trelleborg Rapid Cure*) resins to evaluate their applicability for CIPP. The results show a higher glass transition temperature and final monomer conversion for the frontally cured resin, which cures significantly faster than the reference resins under the same irradiation conditions. In proof-of-concept trials, the newly developed resin successfully cures polymeric liners in a PVC host pipe with 100% water tightness and without losing its structural integrity. Results from ring stiffness tests for cured composite pipes additionally show that liners cured with Trelleborg Self-Curing* resin pass the minimum required Young's modulus for non-pressure drainage pipes as per ASTM F1216. Thus, frontally curable epoxy-based resins are a promising and competitive alternative to acrylates and vinyl esters in CIPP.     

四溴双酚A环氧树脂/二氨基二苯砜固化过程的研究

用高分子材料动态力学谱仪 (TBA)、示差扫描量热仪 (DSC)等方法研究了二氨基二苯砜 (DDS)固化四溴双酚A环氧树脂 (TBBPAER)的固化过程 ,讨论了固化时间、固化剂用量及固化剂的种类等因素对固化物玻璃化转变温度 (Tg)的影响。实验结果表明 ,随着固化时间的延长 ,固化产物的玻璃化转变温度逐渐升高 ,并且在固化初始阶段为一个值 ,到固化中间阶段变为两个值 ,最后到固化末期又为一个值 ,显示出固化产物的结构有所不同 ;适当增加固化剂的用量未超过理论用量的 2 0 %之前 ,可有效地提高固化产物的玻璃化转变温度Tg值 ;选择不同的固化剂 ,可获得具有不同玻璃化转变温度Tg值的固化产物。     

聚三唑酯树脂的合成及其性能

通过酯化反应合成丁二酸二炔丙醇酯(DPS)、间苯二甲酸二炔丙醇酯(DPIP)、对苯二甲酸二炔丙醇酯(DPP),与三官能团叠氮化合物(TAMTMB)反应,制备了3种热固性聚三唑酯(PTAE)树脂,研究了树脂的加工特性、固化行为、树脂固化物的力学性能,制备和表征了T700单向碳纤维增强PTAE树脂复合材料。结果表明,PTAE树脂具有良好的加工性能,可在较低温度(80℃)下固化;固化后的PTAE树脂的玻璃化转变温度(Tg)受主链结构影响,3种树脂的Tg均高于140℃,浇铸体弯曲强度高于170 MPa,T700单向纤维增强PTAE树脂复合材料的常温弯曲强度高于1500 MPa。     

有机硅改性酚醛型环氧固化剂及其固化产物性能的研究

通过聚甲基三乙氧基硅烷(PTS)与环氧丙氧丙基三甲氧基硅烷缩合产物对线型酚醛树脂进行接枝改性,并将其改性产物用于固化环氧树脂。通过制备一系列不同比例改性酚醛树脂并分别与环氧树脂固化。所得的环氧固化产物进行冲击强度、玻璃化转变温度、热失重等测试,结果表明,改性固化产物比未改性固化产物玻璃化转变温度提高了约30℃,冲击强度最高提高了36.6%,高温热稳定性也显著增强。改性产物实现了热稳定性和韧性的综合提升。     

Synthesis of epoxy‐functionalized hyperbranched poly(phenylene oxide) and its modification of cyanate ester resin

High curing temperature is the key drawback of present heat resistant thermosetting resins. A novel epoxy‐functionalized hyperbranched poly(phenylene oxide), coded as eHBPPO, was synthesized, and used to modify 2,2′‐bis (4‐cyanatophenyl) isopropylidene (CE). Compared with CE, CE/eHBPPO system has significantly decreased curing temperature owing to the different curing mechanism. Based on this results, cured CE/eHBPPO resins without postcuring process, and cured CE resin postcured at 230°C were prepared, their dynamic mechanical and dielectric properties were systematically investigated. Results show that cured CE/eHBPPO resins not only have excellent stability in dielectric properties over a wide frequency range (1–10⁹Hz), but also show attractively lower dielectric constant and loss than CE resin. In addition, cured CE/eHBPPO resins also have high glass transition temperature and storage moduli in glassy state. These attractive integrated performance of CE/eHBPPO suggest a new method to develop high performance resins. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation and Application of a New Curing Agent for Epoxy Resin

A new curing agent based on palmitoleic acid methyl ester modified amine (PAMEA) for epoxy resin was synthesized and characterized. Diglycidyl ether of bisphenol A (DGEBA) epoxy resins cured with different content of PAMEA along with diethylenetriamine (DETA) were prepared. The mechanical properties, dynamic mechanical properties, thermal properties, and morphology were investigated. The results indicated that the PAMEA curing agent can improve the impact strength of the cured epoxy resins considerably in comparison with the DETA curing agent, while the modulus and strength of the cured resin can also be improved slightly. When the PAMEA/epoxy resin weight ratio is 30/100, the comprehensive mechanical properties of the cured epoxy resin are optimal; at the same time, the crosslinking density and glass transition temperature of the cured epoxy resin are maximal.     

苯并(噁)嗪和双马来酰亚胺共混树脂性能的研究

将苯并噁嗪(BOZ)和双马来酰亚胺树脂(BMI)按照不同的配比进行共混固化,制备了浇铸体和玻璃纤维增强的层压板。测试结果表明,BOZ和BMI共混的树脂浇铸体线性收缩率为0.85%~0.93%,小于BMI的1.3%略高于BOZ的0.73%。浇铸体和层压板的弯曲强度均随着BOZ含量的增加而上升,并且层压板吸水率还具有不断降低的趋势;其电气绝缘性能较佳。同时该共混树脂体系具有较好的耐热性,其Tg最高达到257℃比单纯BOZ的Tg提高了近50℃。DSC结果表明BOZ/BMI树脂体系的固化反应相对二者各自固化反应向低温移动,使体系中的BMI在相对较低的温度就固化完全。     

Mechanical and thermal properties of epoxy resins with reversible crosslinks

The tensile properties: Young's modulus, ultimate tensile strength, ultimate elongation, the glass transition temperature, and the dynamic mechanical properties (dynamic shear modulus (G'), loss tangent (Tan δ)), of three epoxy resins (Epon 828, Epon 836, Epon HPT 1071) cured with the disulfide-containing crosslinking agent—4.4-dithiodianilme (DTDA) have been characterized. The results show that DTDA is a satisfactory crosslinking agent for the epoxide resins that have been studied as compared to the well-known curing agent methylene dianiline (MDA). There are no significant differences between the properties of Epon 828 cured with DTDA at stoichiometric ratio (2:1) and Epon 828 cured with DTDA at small amine excess ratio (1.75:1). The glass transition temperature of the cured tetrafunctional epoxy resin Epon HPT 1971 (235°C) is significantly higher than that of difunctional epoxy resins such as Epon 828 (T_g–175°C), but the product is too brittle to be used without plasticizer.     

Curing behavior of dicyandiamide/epoxy resin system using different accelerators

Various amounts of dicyandiamide (Dicy), two grades of epoxy resins, i.e. Epiran 06 and Epikote 828, and three different accelerators including benzyl dimethyl amine (BDMA), 3-(4-chlorophenyl)-1,1-dimethyl urea (Monuron) and 2-methyl imidazole (Im) were used in curing of Dicy/epoxy resin system. Both of the used epoxy resins were based on diglycidyl ether of bisphenol A (DGEBA). The effects of type and concentration of accelerators on curing behavior were studied by differential scanning calorimetry (DSC) method in dynamic or non-isothermal mode. The optimum concentration of Dicy for curing of epoxy resins was obtained based on the glass transition temperature of the cured epoxy/Dicy formulations. The maximum glass transition temperature of 139 °C was obtained at the stoichiometric ratio of Dicy to epoxy of 0.65. The results showed that BDMA has a broader curing peak in DSC and starts the cure reaction earlier than the others. However, Monuron has a narrow curing reaction peak with good cure latency. The tensile properties of Dicy-cured Epiran 06 and Epikote 828 epoxy resins reinforced with chopped strand mat showed that these two epoxy resins have similar mechanical properties. For composites based on the Epiran 06 and Epikote 828 reinforced with 40 wt % glass chopped strand mat, tensile strength and modulus were 156 and 153.4 MPa and 11.6 and 12.4 GPa, respectively.