Synthesis and Characterization of Waterborne Epoxy Curing Agent Modified by Silane

A novel waterborne epoxy curing agent was prepared using 3-glycidoxypropyl trimethoxysilane （GPTMS） as a termination agent of adduct, which was synthesized by triethylene tetramine （TETA） and liquid epoxy resin （E-51）. The effects of the reaction temperature and time on the synthesis process were investigated experimentally. The particle size and the distribution of water dispersion of the curing agent were measured by dynamic light scattering（DLS）. The structure of the products was characterized by Fourier transform infrared spec-trometer （FTIR） and ^1H-nuclear magnetic resonance （^1H NMR）. The properties of the synthesized curing agent and the epoxy resin film cured by it were also measured. The results showed that the appropriate temperature for the synthesis of adduct was at 65-75℃ and the reaction time was 4-5h, and that the suitable reaction temperature of curing agent synthesis was 75-85℃ and the reaction time was 3-4h. When the mass ratios of GPTMS and acetic acid were 3%-5% and 5%-10% respectively, the hardness, water resistance and adhesion of the cured film were improved significantly.

Evaluation of the injection and plugging ability of a novel epoxy resin in cement cracks

Sustained casing pressure(SCP)is a crucial issue in the oil and gas production lifecycle.Epoxy resins,exhibiting exceptional compressive strength,ductility,and shear bonding strength,have the potential to form reliable barriers.The injectivity and sealing capacity of the epoxy resin is crucial parameters for the success of shallow remediation operations.This study aimed to develop and assess a novel solid-free resin sealant as an alternative to Portland cement for mitigating fluid leakage.The investigation evaluated the viscosity,compressive strength,and brittleness index of the epoxy resin sealant,as well as its tangential and normal shear strengths in conjunction with casing steel.The flow characteristics and sealing abilities of conventional cement and epoxy resin were comparatively analyzed in cracks.The results showed that the application of a viscosity reducer facilitated control over the curing time of the epoxy resin,ranging from 1.5 to 6 h,and reduced the initial viscosity from 865.53 to 118.71 m Pa,s.The mechanical properties of the epoxy resin initially increased with a rise in curing agent content before experiencing a minor decrease.The epoxy resin containing 30%curing agent exhibited optimal mechanical properties.After a 14-day curing period,the epoxy resin's compressive strength reached81.37 MPa,2.12 times higher than that of cement,whereas the elastic modulus of cement was 2.99 times greater than that of the epoxy resin.The brittleness index of epoxy resin is only 3.42,demonstrating high flexibility and toughness.The tangential and normal shear strengths of the epoxy resin exceeded those of cement by 3.17 and 2.82 times,respectively.In a 0.5 mm-wide crack,the injection pressure of the epoxy resin remained below 0.075 MPa,indicating superior injection and flow capabilities.Conversely,the injection pressure of cement surged dramatically to 2.61 MPa within 5 min.The breakthrough pressure of0.5 PV epoxy resin reached 7.53 MPa,decreasing the crack's permeability to 0.02 D,a mere 9.49%of the permeability observed following cement plugging.Upon sealing a 2 mm-wide crack using epoxy resin,the maximum breakthrough pressure attained 5.47 MPa,3.48 times of cement.These results suggest that epoxy resin sealant can be employed safely and effectively to seal cracks in the cement.

Cure Behaviors and Water Up-take Evaluation of a New Waterborne Epoxy Resin

Cure behaviors and water up-take evaluation of a low cost, ecofriendly and water soluble epoxy resin prepared by reaction between epichlorohydrin and PEG400, PEG600 and PEG1000, respectively, were investigated using non-isothermal differential scanning calorimetry （DSC） and gravimetrical method, respectively. Factors affecting the cure behaviors as well as water up-take of waterborne epoxy resins, such as amount of triethylenetetramine （TETA） and triethylene diamine （TEDA）, PEG molecular weight, curing temperature, were systematically investigated. The prepared water soluble epoxy resins can be cured under room temperature with the shape of the curing curves similar to that expected for an autocatalytic reaction.

MICRO-PHASE SAEPARATION IN EPOXY RESIN WATERBORNE PARTICLES DURING CURING PROCESS

Sub-micron sized phenolic epoxy resin waterborne particles were prepared by phase inversion emulsification. Micro-phase separation occurred during the curing process at high temperature. The as-prepared samples possessed one glass transition temperature （Tg） and two exothermal processes during DSC heating scannings. After being thermally treated above the exothermal peak temperature, they possessed two glass transition temperatures with the disappearance of exothermal peaks, whilst a core/shell structure was formed. This was likely related with the outward diffusion of reactive oligomers to the outer layer of particles.

Bio-Based Hyperbranched Toughener From Tannic Acid and Its Enhanced Solvent-Free Epoxy Resin with High Performance

It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranched toughener,carboxylic acid-functionalized tannic acid(CATA),was successfully prepared and applicated to the preparation of solvent-free epoxy resins.The mechanical performance,morphology,structural characterization,and thermal characterization of toughened epoxy resin system were studied.The toughened epoxy resin system with only 1.0wt%CATA reached the highest impact strength,111%higher than the neat epoxy resin system.Notably,the tensile strength and elongation at break of toughened epoxy resin systems increased moderately with increasing CATA loading.Nonphase-separated hybrids with significant toughening effect were obtained.Additionally,the thermal stabilities of toughened epoxy resin systems decreased with increasing CATA loading.This study provides an eco-friendly,cost-effective,and facile approach for the preparation of high-performance,solvent-free epoxy resins with potential for practical applications in sealing integrated circuits and electrical devices fields.

New flame retardant epoxy resins based on cyclophosphazene-derived curing agents

To obtain high-efficiency flame retardancy of epoxy resins,a cyclophosphazene derivative tri-(ohenylenediamino)cyclotriphosphazene(3 ACP)was successfully synthesized and used as a curing agent for the thermosetting of an epoxy resin system.The flame retardant properties,thermal stability,and pyrolysis mechanism of the resultant thermosets were investigated in detail.The experiments indicated that the synthesized thermoset achieved a UL-94 V-0 rate under a vertical burning test as well as a limiting oxygen index(LOI)of 29.2%,which was able to reach V-0 even when a small amount of 3 ACP was incorporated.Scanning electronic microscopic observation demonstrated that the char residue of the thermosets was extremely expanded after the vertical flame test.Thermal analysis showed that the samples had a lower initial decomposition temperature when 3 ACP was introduced into the epoxy resin systems.This indicates that the carbonization ability of the thermosets was significantly improved at elevated temperatures.In addition,the incorporation of 3 ACP can effectively suppress the release of combustible gases during the pyrolysis process,and the decomposition of E-44/DDS-3 ACP curing systems also promotes the formation of polyphosphoramides charred layer in the condensed phase.The investigation on the chemical structures of both the gaseous and condensed phase pyrolysis process confirmed the flame-retardant mechanism of the 3 ACP-cured epoxy resins.Therefore,the nonflammable halogen-free epoxy resin developed in this study has potential applications in electric and electronic fields for environment protection and human health.

多孔环氧树脂基固体电解质微观结构与性能

文中以聚乙二醇200为制孔剂、双酚A二缩水甘油醚为树脂基体、4,4'-二氨基二环己基甲烷(PACM)和聚醚胺(D230)为固化剂,使用反应诱导相分离法制备了多种多孔环氧树脂,研究了制孔剂比例与固化剂种类对多孔环氧树脂微孔结构的影响。结果表明,随着制孔剂比例增加,PACM体系多孔环氧树脂微孔结构由非贯通圆孔变为由环氧树脂小球连接的贯通结构,而D230体系多孔环氧树脂由独立小孔逐渐发展为三维骨架孔道。D230三维贯通骨架结构更利于制孔剂的去除和离子通道的形成,可在保留较完整树脂骨架的同时获得较高离子电导率(1.81 mS/cm);而PACM海绵状微孔更容易形成闭合孔道,在制孔剂与树脂质量比超过3:1的情况下可获得较高离子电导率(2.02 mS/cm),但此时微观形貌表现为独立树脂小球,失去力学性能。此外,在制备的树脂固体电解质块体结构中,D230体系在更低的制孔剂比例下(制孔剂与树脂质量比为2:1)测得离子电导率(0.35mS/cm),表明大厚度条件下,D230体系三维网络结构对比PACM体系圆孔更有利于形成连续离子通道。

水性有机硅改性环氧树脂的制备与性能

利用二甲基二氯硅烷(DMDCS)与环氧树脂E51中-OH缩合反应合成有机硅改性环氧树脂,并采用相反转法制备水性有机硅改性环氧树脂,以疏水性优选有机硅改性环氧树脂合成条件,分析了乳化工艺对乳液平均粒径的影响,并考察了固化膜性能。结果表明,在环氧树脂40 g、DMDCS 1.6 g、溶剂用量20 mL、50℃反应8 h的条件下,有机硅改性环氧树脂与水的接触角为106.8°;当乳化剂用量为25%、乳化温度为65℃、剪切机转速为3000 r/min时,乳液平均粒径为1.011μm,储存稳定性(30 d)和离心稳定性(3000 r/min,30 min)良好;水性有机硅改性环氧固化膜固化时间短,具有优良的疏水性、力学性能、耐腐蚀性能。

厚朴酚环氧树脂涂层的制备及综合防护性能研究

采用联苯结构的生物质原料厚朴酚合成生物基环氧树脂,以柔性聚醚胺固化剂(D230、D400、D2000及T403)进行固化制备生物基环氧抗冲蚀涂层,探究聚醚胺分子量与官能度对厚朴酚环氧树脂力学性能、防腐性能以及抗冲蚀防护性能的影响,阐述厚朴酚环氧涂层抗冲蚀磨损机理。结果表明:D230固化的厚朴酚环氧涂层在3.5%(质量分数)NaCl溶液中浸泡15 d后仍具有较高的阻抗值(1.25×10^(11)Ω·cm^(2));以T403固化可获得高拉伸强度(26.59 MPa)、低摩擦系数(0.373)和磨损率[0.0183 mm^(3)/(N·m)]涂层;D2000固化的厚朴酚环氧涂层在抗冲蚀测试中表现出较低质量损失(244.74 mg)与体积损失(157 mm^(3))。在固/液/气三相流冲蚀作用下,D2000较长的柔性链段,赋予厚朴酚环氧涂层更好的弹性和柔韧性,降低了冲蚀介质的冲击作用,从而表现出优异的抗冲蚀性能。

1,3-二(2′-氨基亚乙基)-2-甲基咪唑溴盐与环氧树脂E-51的固化工艺

通过咪唑环上的季铵化反应,制备一种适用于环氧树脂的双氨基咪唑类离子液体固化剂1,3-二(2′-氨基亚乙基)-2-甲基咪唑溴盐(DAIL)。以环氧树脂E-51作为基体树脂,深入研究DAIL作为固化剂的固化工艺条件和固化物的性能。结果表明,DAIL可作为环氧树脂E-51的中温固化剂使用,二者的最佳质量比为DAIL∶E-51=20∶100,最佳固化温度范围为74~105℃,后固化温度为162℃,固化后的浇注体样条抗拉强度为159 MPa,弹性模量为2281 MPa,断裂伸长率为12.8%,热分解温度为424.4℃。DMA分析表明DAIL/E-51浇注体最大损耗因子tanδ为0.56,玻璃转化温度θg为83℃,对应的贮存模量E为290 MPa,交联密度为30149 mol·m^(-3)。该结果为高力学性能中温环氧树脂固化剂的使用提供了重要实验依据。

改性异佛尔酮二胺固化剂的制备与固化性能研究

环氧树脂是一种应用广泛的热固性树脂,固化剂在环氧树脂体系占很大的比重。以环氧树脂对固化剂异佛尔酮二胺(IPDA)进行改性,通过不同的配比得到不同性能的改性固化剂。再以不同性能的改性固化剂分别与环氧树脂反应,制得不同的固化样品。运用Gelprof 518树脂行为分析仪对固化过程进行评价分析,对固化样品评价分析,改性固化剂的性能相较于未改性固化剂都有所提高,但性能存在不同,改性IPDA比例为m(NPEL-128)∶m(IPDA)∶m(benzyl alcohol)=9∶46∶45时,反应活性最强。此研究揭示了不同比例固化剂对环氧树脂固化的影响,为工业过程中固化剂改性提供了思路。

高光泽阴极电泳涂料的制备及其性能研究

为提高阴极电泳涂层光泽,将环氧树脂与胺反应并中和,合成水溶性阳离子聚合物分散体,再与季铵盐分散树脂混合研磨制得高光泽阴极电泳涂料专用色浆,并研究主体树脂环氧当量、环氧树脂种类、封闭型异氰酸酯固化剂的封闭剂和异氰酸酯种类、涂料颜基比和色浆细度对阴极电泳涂层光泽的影响。结果表明:当主体树脂环氧当量为400~500 g/mol,使用二聚酸改性环氧树脂制备阳离子聚合物分散体,采用甲苯二异氰酸酯和乙二醇丁醚合成封闭型异氰酸酯固化剂,涂料颜基比控制在0.2左右,色浆细度≤15μm,可制得高光泽阴极电泳涂料,涂层具有良好的机械性能、耐盐雾性和一定的耐老化性能。

水性环氧固化剂的研究及应用进展

水性环氧固化剂是水性环氧树脂自乳化和自固化的关键,其组成、结构对水性环氧树脂性能起着决定性作用。综述了固化剂制备技术,分析了酰胺化多胺法、聚酰胺法及环氧-多胺加成法制备技术及其优缺点,探讨了水性环氧固化剂的应用进展,展望了其未来的发展方向。

低黏度改性异弗尔酮二胺水性环氧固化剂的研制

本文以异佛尔酮二胺、聚乙二醇二缩水甘油醚、双酚A型环氧树脂E51和丙烯酸异辛酯为原料制备了水性环氧胺类固化剂,研究了E51和丙烯酸异辛酯的用量对固化剂黏度的影响,利用傅里叶红外光谱仪对固化剂结构进行了表征。随后进一步研究了不同固化剂所配制的水性环氧涂料的表干时间及其固化涂层的硬度、耐介质及防腐等性能,并研究了不同锌粉含量环氧富锌涂层的耐盐雾性能。结果表明,丙烯酸异辛酯用量越多,合成的固化剂黏度越低,涂料表干时间越慢,固化后的涂层硬度越低、耐介质性越好、吸水率越低、防腐蚀效果越好;锌粉含量越高、耐盐雾性能越好。

Nucleophilic amino acids as a renewable alternative to petrochemically-derived amines in glycerol epoxy resins

The standard epoxy resin curing agents revealed are from unsustainable petroleum-based sources,which produce poisonous exhaust when cured.Amino acids,a bio-based epoxy curing agent with amino and carboxyl groups,are another potential curing agent.Water-soluble epoxy resins cured with lysine(Lys),glutamic acid(Glu),leucine(Leu),and serine(Ser)as amino acids were inves-tigated.The results showed that the water-soluble epoxy resin(glycerol epoxy resins,GER)was cured with Lys and Glu after reacting.Fourier transform infrared(FT-IR)spectroscopic analysis of the GER-Lys showed that the amino and carboxyl groups of Lys primarily reacted with the epoxy groups of GER.The elongation at break of Lys-cured GER(GER-Lys)cured at 70℃ with a molar ratio of 1꞉0.75 was 75.32%.The fact that elongations at break of GER-Lys(79.43%)were higher than those of GER-Glu(17.33%),respectively supports the decrease of crosslinking density by the amino acid-cured GER reaction.The potential of Lys and Glu alternatives for petrochemical amines is demonstrated and provides promising opportunities for industrial application.

乳液型环氧固化剂的制备与性能研究

为制备稳定性良好及高耐性的乳液型环氧固化剂,以三乙烯四胺、聚乙二醇二缩水甘油醚、环氧树脂E51、邻甲苯缩水甘油醚为原料合成了一种非离子反应型乳化剂(NIRE);以二乙烯三胺或间苯二甲胺、环氧树脂E20、苯基缩水甘油醚为原料合成了改性胺作为被乳化物(ES)。利用NIRE与ES之间的疏水性差异,通过相反转法制得乳液型环氧固化剂(WCA),并考察了WCA固化的水性双组分环氧底漆的应用性能。采用红外光谱表征了NIRE、ES的结构;探究了制备NIRE的最佳反应条件;并研究了NIRE用量、乳化温度、剪切速度对WCA性能的影响;以及ES结构中胺的种类及封端率对WCA应用性能的影响。结果表明:当NIRE质量为ES的25%,乳化温度为60℃,剪切速率为2 000 r/min时,可制得粒径小、稳定性良好的WCA,由其制备的水性双组分环氧底漆具有优异的附着力、耐水性和耐盐雾性。

香兰素基环氧树脂的制备及性能研究

以香兰素(VAN)改性4,4-二氨基二苯甲烷(DDM),经脱水缩合反应,合成香兰素希夫碱固化剂(VDM)。在催化剂2-乙基-4-甲基咪唑(EMI)作用下,采用VDM固化双酚A型环氧树脂(E44)。交联后的环氧树脂(E44-VDM)表现出优异的拉伸强度(60MPa)、拉伸断裂率(8.2%)和玻璃化转变温度(109℃)。在高温下,基于亚胺键的交换反应,E44-VDM表现出再加工性、快速的应力松弛和形变恢复行为,根据阿伦尼乌斯(Arrhenius)定律,计算出亚胺键交换活化能为65.15kJ/mol。将E44-VDM分别浸没在酸碱溶液中,经过72h处理后,并未溶解或溶胀,仍能保持结构完整性,显示出优异的耐酸碱性。尽管经再加工的E44-VDM力学性能不可避免地低于原始试样,但VDM可应用于多种环氧树脂体系中,可为缓解环境污染和资源消耗提供解决方案。

水性环氧树脂灌浆材料的制备及渗透性能研究

以水性环氧树脂E51为原料、二乙烯三胺(DETA)为固化剂,制备出了水性环氧树脂灌浆材料,研究了DETA用量对灌浆材料凝结时间、黏度、力学强度和渗透性能的影响。结果表明,随着固化剂DETA质量分数的增加,水性环氧树脂灌浆材料的初凝时间逐渐降低,黏度持续增大,粘接强度先增大后减小,热稳定性提高,热失重速率减慢,残炭率提高,渗透时间增多。当DETA质量分数为30%时,灌浆材料的初凝时间最短为8.0 h,对应时刻的黏度最大为80334 mPa·s;当DETA质量分数为25%时,灌浆材料的粘接强度和抗压强度达到了最大值,分别为2.94和59.9 MPa,对应的断裂延伸率为13.82%;在800℃时,DETA质量分数为25%的水性环氧树脂灌浆材料的残炭率为9.3%,渗透时间为1709 s,热稳定性和渗透性能较好。综合分析可知,DETA的最佳质量分数为25%。

高触变高抗流挂双组分水性环氧涂料的制备

双组分水性环氧涂料具有触变性和抗流挂性不易调节的问题。采用聚氨酯缔合型增稠剂和膨润土复配,并选用乳液型胺固化剂取代常用的水溶性胺固化剂的方式,制备了一款具有高触变、高抗流挂和优异综合性能的双组分水性环氧涂料。研究了增稠剂和流变助剂的种类及用量、胺固化剂的类型对双组分水性环氧涂料的触变性、抗流挂性及其他应用性能的影响规律,结果表明:6870乳液型胺固化剂与299增稠剂和LT膨润土之间存在相互促进作用,当299增稠剂用量为0.5%、LT膨润土用量为0.3%时,搭配6870乳液型胺固化剂可制得触变指数为4.5、抗流挂极限膜厚为475μm、综合性能优异的双组分水性环氧涂料。

抗腐蚀蔓延水性环氧富锌涂料的制备与性能

[目的]要延长涂层的使用寿命,需阻止腐蚀介质沿着涂层被划伤的部位侵入而腐蚀金属基材,抑制腐蚀蔓延。[方法]选用环氧树脂乳液、胺类固化剂、颜填料、腐蚀抑制剂及其他助剂制备了一种具有优异抗腐蚀蔓延能力的水性环氧富锌涂料,讨论了成膜物质含量、固化剂种类和颜填料复配形式对涂层耐蚀性的影响,探讨了涂层抗腐蚀蔓延的机理。[结果]在成膜物质的质量分数为15%,选用聚酰胺固化剂,以绢云母、超磷锌白和石墨烯作为颜填料,并加入适量腐蚀抑制剂的情况下,所制备的涂料综合性能最好,其涂层经中性盐雾试验2 160 h后依然具有良好的附着力,平均扩蚀宽度仅为1.43 mm。[结论]腐蚀抑制剂对涂层湿态附着力的提升,以及石墨烯对锌粉利用率的提升,共同赋予了该涂层优异的抗腐蚀蔓延性能。