Isocyanate-terminatcd Polyethers Toughened Epoxy Resin： Chemical Modification, Thermal Properties, and Mechanical Strength

The toughening of the diglycidyl ether of bisphenol A epoxy resin with isocyanateterminated polyethers （ITPE） was investigated. The progress of the reaction and the structural changes during modification process were studied using FTIR spectroscopy. The studies support the proposition that TDI （tolylene diisocyanate） acts as a coupling agent between the epoxy and polyethers, forming a urethane linkage with the former and the latter, respectively. Me THPA-cured ER/ITPs blends were characterized using dynamic mechanical analysis （DMA） and thermogravimetric analysis （TGA）. It is indicated the glass transition temperature （T） of systems was lower than the T of pure epoxy resin and overfull ITPE separated from the modified epoxy resin and formed another phase at an ITPE-content of more than 10wt%. The thermal stability was decreased by the introduction of ITPE. The impact strength and the flexural strength of the cured modifiedepoxy increased with increasing the ITPE content and a maximum plateau value of about 24.03 kJ/m^2 and 130.56 MPa was measured in 10wt% ITPE. From scanning electron microscopy （SEM） studies of the fractrue surfaces of ER/ITPE systems, the nature of the micromechanisms responsible for the increases in toughness of the systems was identified.     

含硅环氧树脂的制备及其固化动力学研究

采用二苯基硅二醇与邻甲酚醛环氧树脂在SnCl₂ 催化作用下合成了含硅环氧树脂(CNE - Si),并用FT - IR、1 H - NMR对产物进行了结构表征,采用 TGA分析了含硅环氧树脂的热稳定性。结果表明,- Si -基团的引入大大提高了环氧树脂的热稳定性。采用非等温 DSC方法探讨了含硅环氧树脂的固化反应过程,用T -矱外推法确定了含硅环氧树脂在线性酚醛树脂固化剂作用下的固化工艺参数,即：起始固化温度为 110℃,最快的固化反应温度为125℃,后固化温度在170℃附近。用Kissinger和Ozawa法进行了动力学研究,得到了其固化反应活化能、反应级数等动力学参数,为含硅环氧树脂的应用提供了基础数据。     

环氧树脂/BPEA-2潜伏性固化体系固化物的热行为研究

采用热膨胀仪、差式扫描量热分析仪（ Ｄ Ｓ Ｃ） 、热重分析仪（ Ｔ Ｇ） 等方法对 Ｂ Ｐ Ｅ Ａ － ２／ Ｃ Ｙ Ｄ１２８ 潜伏性固化体系的固化物的热稳定性及热形变进行了研究结果表明：体系固化物的热变形温度与固化剂的用量有一定的关系,固化物的热稳定性良好,其初始分解温度在３００ ℃左右,快速分解温区在３００ ～４８０ ℃之间, 体系固化物的热降解活化能约为１６１ ．３ｋ Ｊ／ ｍｏｌ     

开环聚合型酚醛类树脂--苯并恶嗪树脂的研究进展

综合论述了开环聚合酚醛树脂--苯并恶嗪中间体的研究进展,着重介绍了苯并恶嗪的合成、性能、复合材料的研究及其产品的应用开发等方面的进展.结果表明,苯并恶嗪树脂具有良好的固化性能,而且具有较高的耐热性,是一种很有发展前途的新型耐热型树脂.     

纳米氧化铝纤维改性酚醛树脂及性能

采用原位法成功合成了摩擦材料用纳米氧化铝纤维改性酚醛树脂.利用示差扫描量热分析（DSC）对合成树脂的固化反应及其动力学进行了研究,结果表明：纳米氧化铝纤维可降低酚醛树脂的固化温度和表观活化能.通过热重分析（TGA）对合成树脂的热性能进行了研究,结果显示,纳米氧化铝纤维对酚醛树脂热性能的影响较小.通过冲击强度测试和断口形貌分析研究了合成树脂的韧性,结果表明,纳米氧化铝纤维对酚醛树脂韧性有显著影响;随着纳米氧化铝纤维含量的增加,改性树脂的冲击强度先增大,后减小,在含量为1.8%时,达到最大值,与纯酚醛树脂相比,提高了约91%.     

环氧树脂/纳迪克酸酐/乙酰丙酮铬体系固化反应动力学研究

以环氧树脂为主体树脂,酸酐为固化剂,乙酰丙酮铬( Cr(acac)3)为促进剂,通过不同升温速率测定固化体系的DSC曲线来研究该体系的反应动力学历程.运用Kissinger、Ozawa方法计算出固化体系在不同促进剂用量下的表观活化能Ea及指前因子A,结合Crane公式求出反应级数n值近似为1.结果表明:适量的Cr(ac...     

Synthesis and Characterization of Novel Polyarylene Sulfide

A novel polyarylene sulfide, polyarylene sulfide sulfone imide, was polymerized with a new monomer （Dichlorodiimide） and sodium sulfide by taking high temperature （200℃） N-methyl-2-pyrrolidinone （NMP） as solvent. The polymer was characterized by using conventional methods. Physical properties of the polymer, including thermal stability and solubility, were also studied. DSC and TG analyses reveal that the glass transition temperature T is equal to 252.4 ℃ and that the thermal decomposition temperature Td is equal to 484.9℃.     

二元胺/环氧树脂增韧BMI树脂的研究

以4,4＇-二氨基二苯甲烷型双马来酰亚胺为基体,用二元胺和环氧树脂进行增韧,利用红外光谱、示差扫描量热仪及热失重分析仪研究了改性树脂的结构、反应程度和热稳定性．结果表明,二元胺和环氧树脂固化双马来酰亚胺体系中,随固化温度的提高,产物的交联密度升高．与纯组分的双马来酰亚胺固化体系相比较,改性后体系的分解温度降低,柔韧性增加。     

酚醛树脂固化的非模型拟合动力学研究

根据不等温差示扫描量热曲线,采用非模型拟合动力学法对酚醛树脂的固化动力学进行了研究。基于Fried-man,Flynn-Wall-Ozawa和Kissinger-Akahira-Sunose 3种模型计算得到了固化速率及活化能与固化度的关系,进而对此树脂体系的固化反应阶段及固化行为进行了分析,并对等温固化行为进行预测。结果表明,固化反应逐渐从自催化反应机理转变为n阶反应机理,与模型拟合法研究的结果基本吻合。对Friedman,Flynn-Wall-Ozawa,Kissinger-Akahira-Sunose 3种动力学方法进行比较发现,3种方法都显示了较好的拟合结果。其中,Flynn-Wall-Ozawa和Kissinger-Aka-hira-Sunose两种方法的结果十分接近,并能对固化行为进行准确地反映。     

Optimizing pyrolysis of resin carbon for anode of lithium ion batteries

1INTRODUCTION Lithiumionbatterieshaveattractedworldwide attentionandbeendevelopedrapidlyduetotheirhighenergydensity,goodcharge dischargeper formancesandlongcyclelife[14].Theseoutstand ingpropertiesresultfromtheuseofcarbonmateri alsasanodeinsteadoflithiummetal.However,thespecificcapacityofcarbonmaterialsisfar smallerthanthatoflithiummetal(3670mA·h/g).Muchefforthasbeenfocusedonimprovingca pacityofcarbonanodesduringthepastfew years[57].Recentworkindicatedthatdisorderedcar bons,obtainedbypy…     

Melt synthesis and characterization of poly(L-lactic acid) chain linked by multifunctional epoxy compound

High molecular weight(Mw) poly(L-lactic acid)s(PLLAs) were synthesized using multifunctional epoxy compound(Joncryl-ADR4370) as chain extender. The products were characterized by gel permeation chromatography(GPC) and spectroscopy(¹HNMR and FTIR). The results indicated that the Mw of PLLA increased with the increasing of the ratio of epoxy compound and the extending of reaction time. The highest M _w of PLLA reached 360 000 g/mol when the ratio of epoxy compound was 1.5 wt%. However, the reactants turned to cross-linking when the ratio of epoxy compound was over 1.5 wt%. Differential scanning calorimetry(DSC) measurements demonstrated that the glass transition(T _g) and melting temperatures(T _m ) of products increased slightly as the increase of the molecular weight. Analysis of the hydrolytic degradation in vitro showed that the branched PLLA possessed the quicker degradability than that of the linear PLLA.     

Preparation of the Heat Resistant Adhesive of NBR Modified BMI

A Kind of homogeneous resin,which can be used as thermal resistant adhesive and matrix for composite ,was prepared by bis(4-maleimidophenyl) methane(BMI),4,4‘-diaminodiphenylmethane(DDM),aniline(An),phenol type epoxy resin(F-51) and nitrile-butadiene rubber(NBR) through solution eopolymerization.The reaction from prepolymerization to curing of the resin system was studied.And the factors fuch as raw material ratio and curing temperature,which affect thermal resistance and adhesives of cured product,were also analyzed.SEM and IR spectra were utilized to discuss the mechanisms of toughness and reaction of modified BMI.     

双酚A型苯并噁嗪树脂/蒙脱土纳米复合材料的制备与表征

为解决苯并噁嗪树脂(BZ)固化温度高和固化后韧性差的问题,首先制备了苯并噁嗪叔铵盐(Bz盐),并通过阳离子交换反应对蒙脱土(Na-MMT)进行改性,得到Bz盐改性蒙脱土(Bz-MMT);其次,将Bz-MMT与BZ共混,通过除泡和加热固化,制备了苯并噁嗪树脂/蒙脱土纳米复合材料(PBZ/Bz-MMT);最后,采用X射线衍射(XRD)、差示扫描量热法(DSC)和热重分析(TGA)等对Bz-MMT、BZ和MMT的混合物以及固化后的PBZ/Bz-MMT纳米复合材料进行分析,分别考察了Bz盐的用量对Bz-MMT层间距和热稳定性的影响、Bz-MMT对BZ的固化温度以及对PBZ/Bz-MMT热稳定性和力学性能的影响.结果表明:随着Bz盐用量的增加,Bz-MMT的层间距基本不变、有机含量提高、起始热分解温度降低;采用Bz-MMT改性BZ,不仅可以降低BZ的起始固化温度,而且能有效地提高PBZ/Bz-MMT的"残炭率"、拉伸强度和冲击强度.     

三氧化二铝对环氧树脂固化动力学及 热降解动力学的影响

采用热分析法研究了高含量Al₂O₃填料对环氧树脂（E51）/二氨基二苯甲烷（DDM）体系的固化表观活化能、热降解动力学和性能的影响.非等温差式扫描量热法（DSC）固化动力学研究表明,加入Al₂O₃体系的反应活化能由51.49 kJ/mol降低至48.12 kJ/mol;用n级非等温动力学法分析获得了固化反应的动力学参数.利用热重分析研究了环氧固化物体系的热降解动力学,用FWO方法计算固化物降解活化能结果表明,Al₂O₃粉体对E51/DDM体系初始分解活化能影响不大,当降解率达到30%时,Al₂O₃粉体对E51/DDM体系分解有明显的抑制作用.热重红外联用测试结果表明,甲烷、羰基化合物、胺和双酚A是E51/DDM热分解过程中的主要产物,Al₂O₃粉体能提高E51/DDM体系的热稳定性.动态热机械研究表明,Al₂O₃的加入增大了环氧树脂固化产物的储能模量.DSC测试结果表明,Al₂O₃加入后,体系的玻璃化转变温度由114.16℃提高到121.51℃.     

聚醚胺/环氧树脂固化体系的动力学研究及性能

以聚醚胺类化合物作为环氧树脂的固化剂,得到的固化体系相对脂肪胺及简单二胺为固化剂的固化体系具有良好的弯曲强度和抗冲击性能。并采用DSC测试方法研究了环氧树脂与聚醚胺的固化进程动力学参数,由Kissinger方程得出固化反应的活化能E为51.91kJ/mol,频率因子A为3.214×106 s-1,由Crane方程得出固化反应级数n=0.887 9,并得到固化反应的动力学方程,-dα/dt=k（1-α）0.887 9,其中k=3.214×106exp（-6 243.7/T）。     

Thermal stability, thermal decomposition and mechanism analysis of cycloaliphatic epoxy/4,4′-dihydroxydiphenylsulfone/aluminum complexes latent resin systems

The thermal stability of latent resin systems, cycloaliphatic epoxy/4,4??-dihydroxydiphenylsulfone/aluminum complexes, was investigated by dynamic differential scanning calorimetry (DSC) analysis. Experiments were conducted under non-isothermal condition in a nitrogen atmosphere at the heating rate of 10, 20, 30 and 40 °C/min, respectively. TG curves showed that, in the temperature range of 25 to 600 °C, the stability of the resin systems could be enhanced by increasing the length of the aliphatic chain in the initiator. Both the Kissinger method and the Ozawa-Flynn-Wall method were employed to calculate activation energies of the decomposition reaction, and the values obtained from the two methods were compared. Moreover, the corresponding reaction mechanism was identified by the Achar differential method and the Coats-Redfern integral method. The experimental results showed that these four methods were reliable and effective to study the kinetics of the thermal decomposition reaction; and the most probable thermal decomposition mechanism of the resin systems we proposed was found to comply with Mampel power law (m=1).     

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.     

硼胺络合物／环氧树脂体系的固化反应

应用ＤＳＣ和ＩＲ分析技术，研究了含有恶硼杂环的硼胺络合物与环氧树脂体系的固化反应机理和固化反应动力学。结果表明，固化反应主要是硼胺络合物与体系中羟基化合物形成含氢质子的配位络合物，然后由此引发体系的环氧基进行的阳离子开环聚醚反应，整个固化反应过程遵循一级动力学方程。     

DSC及IR联合测定环氧树脂-双氰胺体系固化工艺参数

采用非等温DSC法研究了固化剂用量对环氧树脂固化反应的影响。同时利用不同升温速率下测得的DSC曲线研究了环氧树脂-双氰胺体系的固化反应动力学,并由DSC及IR分析技术确定了该体系的最佳反应条件。实验结果表明：固化剂双氰胺最佳用量为5．6％,最佳固化温度为403K,固化时间为70min,该体系的反应活化能为96．82kJ／mol,反应级数为0．93。     

环氧树脂／粘土纳米复合材料固化反应动力学及其性能的研究

用十六烷基三甲基溴化铵直接处理钙基蒙脱土（MMT）,采用非等温DSC法研究了E-51/MMT/DDM体系的固化反应动力学,并用Kissinger方法求得其表观活化能（△E）为49．66kJ／mol,根据Crane理论计算得到反应级数为0．88,确定了使用DDM作为固化剂的固化反应条件,并且测定了复合材料的力学性能,最后又采用非等温DSC法研究了环氧树脂,粘土纳米复合材料的热性能,研究结果表明纳米复合材料具有较高的玻璃化转变温度。