环氧改性胺固化剂在施工中的应用

介绍改性胺固化剂在环氧体系施工中的作用 ,叙述了低成本、高性能、高效益的环氧涂料固化体系的优良特性     

水性环氧-二乙烯三胺固化剂的合成研究——固化剂胺值与表观活化能的关系

环氧涂料优良的综合性能，使其在防腐涂料、工业地坪涂料、建筑涂料等领域得到了广泛的应用。但目前使用的环氧涂料主要为溶剂型涂料，随着世界各国相继提出有关环境污染限制的法律与法规，各国涂料研究工作者都致力于将其水性化，因此环氧涂料固化剂的水性化随之也发展起来。     

用于环氧的胺固化剂

胺固化的环氧类 用胺固化的环氧广泛用于维护用的环氧涂料,这类环氧包括活性酰胺和酰胺多胺交联类型。大多数胺固化系统是快速反应类型,这种系统用于涂料工业的是双组份室温固化涂料。胺固化环氧的所有反应是基于用胺活泼氢打开环氧乙烷环(图1)。另外,固化剂主链的分子结构和胺氢的性质大大地影响反应速率和最终热固物的化学和物理性能,例如,脂肪族伯胺氢比仲胺氢稍活泼些(可能由于位阻效应);相反,芳香族胺类反应十分缓慢,除非改性,否则不适用室温固化。     

环氧树脂胺类固化剂的改性

总结了环氧树脂改性胺固化剂种类 ,制法 ,性能与应用情况     

改性曼尼希胺水性环氧固化剂的制备及性能

以聚醚胺(D-230)和DMP-30为原料,利用胺交换反应制得一种新型的改性曼尼希胺(MA1)。然后以自制的端官能环氧聚合物(PEG-EP)与低相对分子质量液体环氧树脂(EP)为扩链剂对MA1进行扩链改性,并用苯基缩水甘油醚(PGE)封端,最后采用相反转法制得了一种新型的改性曼尼希水性环氧固化剂。讨论了PEG-EP的添加量、MA1与EP的加料比及封端剂的添加量对水性固化剂体系稳定性的影响。并采用物理化学方法对反应程度及涂膜的性能进能了表征分析。优化体系固化涂膜硬度229 s,柔韧性1 mm,附着力0级,适用期5 h,耐水性优异。     

改性胺类环氧固化剂的研制

介绍了由苯基苯酚生产中的副产物杂酚为原料,制备酚醛改性胺类环氧固化剂的合成工艺,产品分析,实际应用情况等。     

腰果壳液改性胺环氧固化剂投产

卡德莱化工（珠海）有限公司已产出腰果壳液改性胺环氧树脂固化剂，属天然长链取代酚醛胺固化剂。含有脂肪族氨基、弱酸性的酚羟基以及苯环上带的含双键C15长链。这种独特的分子结构使其兼具一般的酚醛胺和低分子聚酰胺的性能。与环氧树脂配合适用期长，混合比例不严格，可室温快速固化，也能在低温、潮湿条件下固化。无毒，固化产物韧性、耐水性、耐磨性、耐腐蚀性优良。     

水性环氧-二乙烯三胺固化剂的合成研究--固化剂胺值与表观活化能的关系

通过对合成的环氧-二乙烯三胺的凝胶时间测试,和由此而得来的表观活化能以及它与胺加成物的胺值之间的关系来考察固化剂的反应活性规律。研究了不同摩尔比、反应时间、反应温度、溶剂种类等对反应活性的影响。     

硫脲改性胺类环氧固化剂

武汉理工大学材料学院对硫脲改性胺类（3,3,-二乙基4,4,-二氨基二苯甲烷和二元脂肪胺A）固化剂固化环氧树脂进行了系统研究。所用3,3,-二乙基4,4,-二氨基二苯甲烷简称DEDDM,又称H-256（江阴惠峰合成材料有限公司）。未改性的H-256反应活性较低,与环氧树脂在120℃反应时,922．0s凝胶,1906．5s放热缓慢,反应放热最高峰值温度只有142．3℃。而以硫脲改性后的H-256活性很高,在120℃下与环氧树脂反应时119．0s内凝胶,149．5s便能固化,固化反应放热剧烈,最高峰值温度达到222℃。     

环氧油酸改性多胺——环氧树脂预聚物作环氧树脂固化剂

以环氧油酸改性的多胺与一定量环氧树脂预聚后，得到吸湿性小，室温活化期长，无挥发的新型环氧树脂固化剂。     

芳香胺改性双氰胺固化环氧树脂反应动力学研究

通过示差扫描量热法分析(DSC)研究了芳香胺改性双氰胺/环氧树脂E-44体系的固化反应,并探讨了反应的机理。结果表明,芳香胺改性双氰胺对环氧树脂E-44具有较高的固化反应活性,反应表观活化能明显降低,固化反应可以在中温进行。其固化反应机理与未改性的双氰胺环氧体系不同。     

改性脂环胺固化剂的合成与性能

固化剂对环氧树脂的性能有着决定性的影响。合成了一种改性脂环胺类环氧树脂固化剂,探讨了合成工艺条件与固化剂性能的关系。合成的固化剂用于配制环氧树脂建筑结构胶,胶粘剂的综合性能良好,能满足GB50367—2006《混凝土结构加固设计规范》对结构胶的要求。     

低粘度酚醛改性胺环氧固化剂的性能研究

采用非等温DSC法对自制的低粘度酚醛改性胺固化剂与环氧树脂的固化反应工艺参数进行了推导,并通过测试体系的固化度加以验证。固化物采用红外光谱进行了表征,同时测定了浇注体的力学性能、热性能(TG),并通过扫描电镜(SEM)对拉伸断裂面的表面形貌进行了观察。结果表明:环氧树脂E-51与自制固化剂的质量比为100∶35,固化工艺条件为常温/24 h+80℃/2 h时,体系力学性能最佳,拉伸强度55.2 MPa、弯曲强度92.8 MPa、压缩强度83.0 MPa,断裂伸长率2.2%,Tg达到280.3℃。该固化剂粘度低、耐热性好、具有很好的柔韧性,可用于建筑结构胶。     

聚氨酯改性糠酮环氧胶的研究

利用聚氨酯预聚体PU中活泼的-N=C=O与糠酮树脂中的羟基等含活泼氢的基团在有机锡催化下合成了聚氨酯接枝改性糠酮环氧结构胶粘剂。结果表明,以双丙酮醇代替丙酮合成的PU改性糠酮环氧胶在改性胺和催化剂作用下具有简便的合成工艺、较低的起始粘度和良好的施工操作性能,并具有较高强度和弹性,压缩强度高达92.7MPa,屈服应变10%,破坏压缩形变大于20%,对非极性聚乙烯的拉伸剪切粘接强度提高一倍以上。     

Influence of chemical structure of hardener on mechanical and adhesive properties of epoxy polymers

The mechanical and adhesive properties of epoxy formulations based on diglycidyl ether of bisphenol A cured with various aliphatic amines were evaluated in the glass state. Impact and uniaxial compression tests were used to determine the impact energy, elastic modulus and yield stress, respectively. The adhesion tests were carried out in steel–steel joints using single‐lap shear, T‐peel, and impact adhesive joints geometry. The better mechanical and adhesive behavior of the networks is obtained when exists high flexibility of chain between crosslink and/or high elastic modulus. The 1‐(2‐aminoethyl)piperazine epoxy network presents the best adhesive properties, high flexibility, and the largest impact energy. However, it possesses low elastic modulus and yield stress. Also, exhibits increases in peel strength and impact energy while reductions in lap shear strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

环氧丁羟环氧值测定方法的研究

研究了在盐酸-四氢呋喃介质中,以酚酞-乙醇作指示剂,氢氧化钠溶液返滴法测定环氧丁羟(EHTPB)的环氧值的方法,考察了反应时间、反应温度、反应介质、指示剂对结果的影响.最终确定了在常温下,EHTPB样品在盐酸-四氢呋喃[V(盐酸):V(四氢呋喃)=1:40]介质中搅拌溶解后静置30 min,以10 g/L酚酞-乙醇作指...     

酚醛胺/环氧树脂胶粘剂耐化学介质性能研究

以自制酚醛胺作为环氧树脂(EP)的固化剂,研究了酚醛胺/EP胶粘剂的耐化学介质性能和耐久性。结果表明:酚醛胺/EP胶粘剂在水、10%NaOH和2%NaCl溶液中浸泡48 h时,其剪切强度分别为6.61、4.66、5.12 MPa,其强度保留率分别为87.90%、61.97%、68.09%;酚醛胺/EP胶粘剂既具有良好的耐水性、耐碱性和耐盐性,又具有较好的碱、盐耐久性,可作为特种胶粘剂——水下胶粘剂广泛用于房屋、水利、地下建筑、医疗、仿生和养殖等领域,并具有良好的经济效益和应用前景。     

风电叶片用EP胶粘剂的研究

以不同增韧剂改性EP(环氧树脂)为基体树脂,采用曼尼希改性胺为固化剂制备了不同改性EP胶粘剂。研究结果表明:当增韧剂为聚氨酯(PU)预聚体时,相应的改性EP胶粘剂的粘接性能优异;在上述体系中加入玻璃纤维增强填料后,相应的改性EP胶粘剂的综合力学性能和粘接性能俱佳,其拉伸强度超过75.00 MPa、拉伸模量超过4.00 GPa、断裂伸长率超过4.00%且90°剥离强度超过10.00 kN/m,属于高韧性EP胶粘剂,并且完全满足风电叶片的使用要求。     

Chemical resistance of waterborne epoxy/amine coatings

Waterborne epoxy/amine coatings, compared to solvent-based, show considerably lower chemical resistance. This fact is often blamed on hydrophilic emulsifiers or crosslinking agents remaining inside the coating after curing. To judge this assertion, the influence of surfactants and hardeners, as well as various other parameters were investigated. Surfactants appear just to influence the solvent resistance slightly. The main responsibility for the poor resistance to other chemicals – especially acids – lies with unreacted amine curing agents and/or water trapped inside the coating, and, most important, an inhomogeneous film structure due to insufficient coalescence during the curing process. Incremental improvements are possible by using excess epoxy, increasing the film thickness, or curing at elevated temperatures. The latter forces water out of the coating, drives the epoxy/amine reaction to completion, and also somewhat improves the coalescence. However, the resistance can still not be enhanced to the level of a solvent-based system. But although there seem to be inherent limitations to the chemical resistance of waterborne epoxy systems, for many practical applications it is adequate.     

Self-healing performance assessment of epoxy resin and amine hardener encapsulated polymethyl methacrylate microcapsules reinforced epoxy composite

In order to study the effect of healing materials viscosity on the self-healing performance of polymer composite, mostly available epoxy resin of viscosity 10–12 Pa.s and amine hardener of viscosity 0.01–0.02 Pa.s were chosen as two different healing materials and successfully encapsulated. Effect of core to shell(c/s) ratio on the synthesis of epoxy microcapsules was investigated and 1:1 c/s ratio is suggested as an ideal ratio to synthesize epoxy capsules. Chemical structure and thermal decomposition patterns of both microcapsules and capsules reinforced composite were analyzed. Tensile strength, impact strength and fracture toughness of capsules reinforced self-healing epoxy composite were evaluated. It was observed that the toughness of epoxy composite increased with the increase in microcapsules concentration. An optimum healing efficiency of 66% was observed with the addition of 7.5 wt% epoxy and hardener microcapsules at equal weight ratio. Stresses developed in the pure epoxy composite crack front were analyzed using Ansys V18.1.