Preparation and characterization of polylactide/montmorillonite nanocomposites

The montmorillonite, a form of layered silicate, was successfully intercalated into polylactide (PLA) matrix through solvent-casting technique. In addition, PLA/MMT nanocomposite films were produced, in which homogenous distribution of the silicate lamellae plays a key role in the mechanical properties of the films. A small amount(5wt%) of OMMT intercalated into the PLA matrix resulted in their flexibility enhancement, from 3.68%(pure PLA film) to 352.65%. The results of wide-angle X-ray diffraction (WAXD) patterns confirmed that the silicate interlayer distance increased from 3.044 nm (for OMMT) to 3.56nm (for 5wt%, maximum) with increasing OMMT contents, but decreased to 3.319 nm when OMMT content was over 8wt%. FT-IR also verified the molecular-level associations between PLA chains and OMMT lamellae by vibration variances of hydrogen bonding. DSC thermograms demonstrated that thermal stabilities of the nanocomposite films enhanced, due to the silicate lamellae dispersed into PLA matrix.     

快速固化环氧-聚硫密封胶的研究

以环氧树脂E-51、液态聚硫橡胶JLY-124及各种助剂为原料制成了一种粘结性优良、可快速固化的环氧-聚硫密封胶.研究了环氧树脂、催化剂对密封胶性能的影响.实验结果表明:采用环氧树脂与液态聚硫橡胶高温预反应工艺制备的密封胶有较好的粘结性能,并且通过添加适量的催化剂可以达到密封胶在低温条件下快速固化的目的.     

EVA/蒙脱土纳米复合材料的阻燃性能

采用熔融插层法制备乙烯-醋酸乙烯酯/有机蒙脱土纳米复合材料(EVA/OM-MT),并研究其阻燃性能。结果表明,EVA大分子能有效地插入有机蒙脱土(OMMT)片层间,形成插层型纳米复合材料,而不能有效插入钠基蒙脱土(MMT)片层间;OMMT可以明显地改善EVA/OMMT的阻燃性能,随着OMMT用量的增大,EVA/OMMT的热释放速、峰值热释放速率、总热释放先明显降低然后趋于稳定。     

环氧树脂改性聚氨酯羟基组分的合成及应用

为提高发泡聚氨酯材料的界面粘接性能,利用二乙醇胺与环氧树脂反应合成端羟基环氧树脂,再将其涂敷于发泡模具的内表面,加入聚氨酯羟基组分并与稍过量的异氰酸酯组分混合均匀后发泡成型,制得环氧树脂改性聚氨酯泡沫材料.研究了合成反应的温度、时间、配比以及反应动力学方程.红外光谱分析结果显示产物的环氧基特征吸收峰消失,且羟基特征吸收峰增强变宽,说明环氧基参与了反应并生成了端羟基环氧树脂.性能测试实验的结果表明:环氧树脂改性聚氨酯具有凝胶、固化快等特点,环氧树脂链段的引入可以将聚氨酯发泡材料的界面粘接强度提高约57％.     

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.     

Creep behaviour of wood flour/poly(vinyl chloride) composites

The experimental creep data were focused on wood-flour (WF) /poly vinyl chloride (PVC) composites with the variations in additive concentrations of wood flour, silane coupling agent, organomodified montmorillonite (OMMT) and nano-cacium carbonate (nano-CaCO₃). Their effects were analyzed using the Four-element Burger Model incorporating microscopic mechanisms. Total creep strain was low with increasing WF while elastic strain was high and plastic flow strain was low in modeling. Modification of WF with silane was beneficial to creep resistance, so did adding low ratio of OMMT (1.5 wt%) and nano-CaCO₃ in composites. Thus, it was effective in reducing creep either by stiffening the PVC matrix using rigid nano-particles or by improving their adhesion with resin. However, superfluous quantity of any additament did not benefit the improvement owing to either earlier destruction of their agglomerates or stress-concentrated cracks in the over-incrassated interface.     

路面裂缝修复用环氧-沥青乳液粘合剂的研究

采用自制的环氧树脂（EP）乳液为改性成份,与SBS改性乳化沥青复配,制备了一种可用于沥青混凝土路面裂缝修复的环氧-沥青乳液粘合剂。分析了EP乳液对粘合剂性能的影响。研究结果表明：EP乳液的加入可明显提高粘合剂的硬化速度和固化物的软化点,并大大改善了SBS改性乳化沥青的力学性能,粘结强度、抗拉强度、低温柔韧性和断裂伸长率均有明显的提高。但EP乳液加入量过大时会降低粘合剂的贮存稳定性。综合考虑,EP乳液加入量为SBS改性乳化沥青的30%左右最适宜.     

不饱和树脂绝缘阻燃漆的合成与性能研究

通过在环氧树脂中引入双键合成不饱和环氧树脂,加入稀释剂苯乙烯制备无溶剂型绝缘漆,通过电阻率和介电损耗对其绝缘性能进行表征.研究不同阻燃剂对绝缘漆体系的阻燃性能、电性能和力学性能的影响.通过DSC研究绝缘漆体系的固化工艺条件.实验结果表明,绝缘漆体系中当三聚氰胺磷酸盐（MP）质量分数为30%时,体系的阻燃性能达到UL0-94 V-0级,绝缘阻燃漆的电阻为7.8×10^13Ω,电阻率为4.36×10^15Ω.·cm,介电损耗为0.014 5,此时拉伸强度为3.34MPa,冲击强度为0.71 kJ/m^2.     

微晶高岭石/环氧树脂复合改性水性聚氨酯的研究

用十六烷基三甲基溴化铵,十二烷基三甲基溴化铵,对微晶高岭石进行有机化处理,得到有机微晶高岭石;以有机微晶高岭石、环氧E-51复合改性,制备了有机微晶高岭石/环氧树脂复合改性的水性聚氨酯（OMMT/E-51WPU）。研究了有机微晶高岭石、2,2-二羟甲基丙酸和环氧E-51的质量分数对乳液及涂膜物化性能的影响。结果表明：当w（OMMT）=1.5%,w（DMPA）=4.0%,w（E-51）=4.0%,乳液及膜的物化性能较好,乳液呈透明蓝光,吸水率为5.9%,接触角98°,拉伸强度32MPa,断裂伸长率571%。     

环氧树脂/蒙脱土纳米复合材料的制备及性能研究

采用双子季铵盐对蒙脱土进行有机化处理，再与环氧树脂进行插层复合制备了环氧树脂／蒙脱土复合材料、借助XRD和FTIR等手段对改性蒙脱土进行了表征，对复合材料的力学性能进行测试。结果表明，改性使蒙脱土层间距增大，有机蒙脱土的加入改善了环氧树脂基体的力学性能，当有机蒙脱土质量含量为1％时，其弯曲强度、冲击强度等力学性能得到了最大的提高。     

无溶剂绝缘浸渍漆的研究进展

介绍了无溶剂浸渍漆的常规性能,阐述了环氧树脂绝缘浸渍漆、不饱和聚酯绝缘浸渍漆、二苯醚树脂绝缘浸渍漆、聚酯酰亚胺绝缘浸渍漆、聚酰亚胺绝缘浸渍漆和有机硅绝缘浸渍漆等无溶剂绝缘浸渍漆的研究现状,并展望了其发展趋势。     

环氧-酚醛-聚酰胺树脂掺混清漆

应用溶解度参数理论,通过对环氧树脂、聚酰胺树脂、酚醛树指３种树脂均相溶液的适当掺混,并对各种清漆配方性能测试比较,造反出附着力好、抗冲击强度好、耐酸耐碱等化学腐蚀性强等综合性能优良的溶剂型环氧－酚醛－聚酰胺树脂清漆。其适宜配方（ｗＢ）为：Ｅ－４４环氧树脂３０．５２％,低分子聚酰胺树脂１０．２６％,酚醛树脂１０．２７％,邻苯二甲酸二丁酯３．５１％,二甲苯／环乙酮（质量比１／１）８．９４％,二甲苯／正     

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.     

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

The toughening of the diglycidyl ether of bisphenol A epoxy resin with isocyanate-terminated 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 g )of systems was lower than the T g 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 modified-epoxy increased with increasing the ITPE content and a maximum plateau value of about 24.03 kJ/m2 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.     

改性蒙脱石及其不饱和聚酯树脂纳米复合材料

以天然钙基膨润土为原料,制备稳定的钠基蒙脱石悬浮液.再以邻苯二甲酸为改性剂,Co2＋作为沉淀剂,制备有机蒙脱石,并探索了原料配比对蒙脱石改性效果的影响.XRD表明：经邻苯二甲酸改性的蒙脱石d001层间距被撑开到1.31823 nm,说明部分有机物进入到蒙脱石层间,制备出了半剥离状态的有机蒙脱石.将制得的有机蒙脱石与不饱和聚酯树脂原位复合,并对复合材料的冲击强度进行测试.结果表明：与纯不饱和聚酯树脂相比,当有机土的添加量为3%时,复合材料的冲击强度是不饱和聚酯树脂的1.43倍.     

Influence of clay concentration on the morphology and properties of clay-epoxy nanocomposites prepared by in-situ polymerization under ultrasonication

To investigate the effect of clay concentration on the structures and properties of bisphenol-A epoxy/nanoclay composites, three composites with organoclay concentrations of 2.5wt%,5wt%,and 7.5wt% of the epoxy resin were prepared by in-situ polym- erization under mechanical stirring followed by ultrasonic treatment.The clay aggregates on micro-scale indicate the absence of fully exfoliated nanocomposites.The layer space decreases with the increase of clay concentration,which suggests that the exfoliation would be constrained if more clay is added as the ultrasonic force is exerted.The thermal decomposition temperature remains almost unchanged with the increase of clay concentration.The glass transition temperature of the composites decreases slightly with the in- crease of clay concentration,whereas the storage modulus increases with the increase of clay concentration.     

加固混凝土用改性环氧树脂粘结性能的研究

采用丁腈橡胶增韧改性环氧树脂,制备了常温固化的加固用粘结材料。从化学反应和显微结构2个方面研究了增韧机理,确定了共混体系的制备工艺参数。通过拉伸剪切试验和拉伸试验,对不同橡胶含量的增韧改性环氧树脂固化产物的力学性能进行了研究,结合显微结构分析研究了增韧改性效果。采用弯曲性能试验表征粘结材料的粘结性能,以破坏形态和最大破坏载荷值为依据,确定了加固用粘结材料的最佳增韧剂含量。     

超声波钠化改型膨润土

以钠型阳离子交换树脂为钠化剂,采用超声波对天然钙基膨润土进行钠化改型.实验考查反应条件对钠基蒙脱石收率的影响,确定适宜的钠化条件为：土浆质量分数为9%,树脂与天然钙基膨润土的质量比为0.5∶1,超声波作用时间40 min,温度为70℃,收率达到49.55%.所制钠基蒙脱石CEC值为97.19 mmol/100 g,通过XRD测得的层间距d001=1.285 9 nm.     

Preparation and characterization of urea-formaldehyde resin/reactive montmorillonite composites

The urea-formaldehyde resin/reactive montmorillonite composites were prepared by in situ polymerization. The reactive montmorillonite was prepared firstly by being ion exchanged with organic molecules and secondly by being grafted with silane coupling agent, which could be demonstrated by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) revealed that the morphology of the urea-formaldehyde resin/reactive montmorillonite composites were ellipsoid or columnar particles. Energy dispersive spectrometry (EDS) confirmed that the reactive montmorillonite was encapsulated by urea-formaldehyde resin. Differential scanning calorimetry (DSC) indicated that curing process of the urea-formaldehyde resin/reactive montmorillonite composites consumed more energy than pure urea-formaldehyde resin. Thermogravimetric analysis (TGA) showed that the thermal stability of the urea-formaldehyde resin/reactive montmorillonite composites improved compared to pure urea-formaldehyde resin. Furthermore, the reactive montmorillonites reduced the formaldehyde emission of the composites and increased the water resistance. Finally, the mechanism to prepare the urea-formaldehyde resin/reactive montmorillonite composites was proposed.     

尼龙66/蒙脱土纳米复合材料的制备及其电性能

用聚合物蒙脱土纳米复合材料的方法,首先,将尼龙66（PA66）和有机改性的Na-蒙脱土（OMMT）采用熔融共混,得到尼龙66/OMMT复合材料。在制备完成时,用X射线衍射仪研究PA66/OMMT中晶型变化与插层效果的影响。研究复合材料的热性能、微观结构、表面电阻和结晶行为,结果都表明OMMT对PA66有明显的影响。DSC显示出OMMT存在对PA66/OMMT复合材料非等温结晶行为的影响。OMMT的含量对OMMT在PA66基体中的分散以及材料的导电性质都有重要的影响。