环氧基POSS/PAMAM杂合材料的制备及性能研究

以3-缩水甘油基氧丙基三甲氧基硅烷(EPTMS)为原料,合成得到了八官能团缩水甘油醚-多面体低聚倍半硅氧烷(简称POSS-EP)。采用4代树型端氨基聚酰胺-胺(PAMAM)作为POSS-EP和双酚A型环氧树脂(DGEBA)共混物的固化剂,制备了5个环氧基POSS/PAMAM杂化材料。通过动态差示扫描量热仪(DSC),研究了环氧和PAMAM的固化反应动力学。通过DSC、热重分析(TGA)、拉力和冲击测试,对环氧基POSS/PAMAM杂化材料的热性能和力学性能进行了研究。结果表明,该环氧基POSS/PAMAM杂化材料具有优良的热性能和力学性能。     

Nanoindentation Studies of Nano Alumina-Reinforced Ether-Linked Bismaleimide Toughened Epoxy-Based Nanocomposites

The scope of the present work is to toughen the commercial epoxy resin using ether linked bismaleimide (e-BMI) with varying chain lengths C4 and C8. The C4 e-BMI toughened system proves to exhibit synergistic effect on both tensile and impact strengths. Hence the secondary objective of the work is to study the effect of nano alumina on C4 e-BMI toughened epoxy. To overcome the disadvantages generated by the loose nanoparticle agglomerates dispersed in polymer composite, the nanoparticles were functionalized using 3- Glycidoxypropylmethoxysilane (GPS). The nanoindentation behavior of the C4 e-BMI epoxy matrix filled with GPS alumina was studies using Nanoindentation. The strengthening of the matrix interaction by the means of covalent bonding and better dispersion of nanoparticles resulted in enhanced nanohardness and elastic modulus. The addition of GPS Al₂O₃ nanoparticles to 15 wt.% C4 e-BMI/epoxy matrix increases the nanohardness and elastic modulus up to 5 wt.% of filler loading beyond which the hardness and elastic modulus decrease.     

Effect of Ultraviolet Radiation and Potassium Permanganate on the Physico-Mechanical Properties of Jute Polymer Composites

Jute fabrics-reinforced polymer composites were prepared with different formulations using oligomer (M-1200), methanol and benzoyl peroxide. Fiber content in the composites was optimized and 55% jute content at oligomer: methanol: benzyl peroxide = 75:24.5:0.5 (w/w) ratios showed better mechanical properties. Jute fabrics were treated with potassium permanganate (KMnO₄) solution of different concentrations for different soaking times. Optimized jute fabrics were soaked in the optimized formulation (F3) and cured under UV radiation at different intensities and measured their mechanical properties. Scanning electron microscopy (SEM), water uptake and soil degradation test of the treated and untreated composite samples were performed.     

Nano/Micro Particle Hybrid Composites for Scratch and Abrasion Resistant Polyacrylate Coatings

Summary: UV curable acrylate formulations with a high content of fumed, nano‐sized silica were prepared to improve their application for abrasion and scratch resistant top coats. Grafting of trialkoxysilanes onto the surface of nanoparticles facilitated their embedding in the formulation and alleviated the effect of undesired increase in viscosity and dilatancy. Modified nanoparticles were obtained from several organosilanes and characterized by a multitechnique approach. To avoid problems during redispersion, in situ modification of nano‐sized silica was performed using the liquid acrylate formulation as a diluting and deagglomerating agent. These nanocomposite materials exhibit markedly improved properties as compared to neat acrylate coatings, e.g. heat, scratch, and abrasion resistance. However, a much better abrasion resistance was obtained for coatings containing both silica nanoparticles and corundum microparticles. By using various grades of corundum, a synergetic effect of nano/micro hybrid composite materials has been studied for parquet and flooring applications.

Pictures of neat polyacrylate coating (on the left) and nano/micro hybrid composite material (18 wt.‐% silica +15 wt.‐% corundum) on parquet substrate after Taber Abraser Test.     

Studies of the Physico-Mechanical,Interfacial, and Degradation Properties of Jute Fabrics/Melamine Composites

Jute fabrics/melamine composites (20% fiber) were prepared by compression molding. Mechanical properties of the composites were evaluated. Mechanical properties of starch-treated jute/melamine composites, including tensile strength (31%), bending strength (29%), tensile modulus (23%), bending modulus (25%), impact strength (113%), and hardness (4%), inproved significantly over the untreated composite. Fracture surfaces of untreated and treated composites were studied by scanning electron microscopy (SEM) and supported poorer fiber matrix adhesion for the untreated composite than that of the treated composite. Water uptake and soil degradation tests of untreated and treated composites were also performed.     

纳米碳化硅改性聚四氟乙烯复合材料的摩擦磨损性能

采用不同偶联剂对纳米碳化硅进行表面处理后,制备了聚四氟乙烯/纳米碳化硅复合材料,考察了偶联剂种类和含量随载荷变化对复合材料摩擦磨损性能的影响,并利用扫描电子显微镜观察和分析了复合材料磨损表面形貌及其磨损机理。结果表明,经表面处理的纳米碳化硅填充后的复合材料硬度和摩擦磨损性能均有提高,以钛酸酯偶联剂（NDZ101）处理效果最好;随着偶联剂含量的增大,钛酸酯偶联剂（NDZ101）处理的复合材料的磨损量和摩擦因数均增大,偶联剂最佳含量为填料质量的1 %;偶联剂处理后的纳米碳化硅与基体之间形成了良好的界面,复合材料的磨损以黏着磨损和磨粒磨损为主。     

LLDPE／纳米SiO2复合材料的制备与性能研究

利用超声波分散，偶联剂对纳米SiO2进行了表面改性，用共混法制备了LLDPE/纳米SiO2复合材料，系统研究了该种新型复合材料的静态，动态力学性能和红外吸收性能，并与球磨机分散，偶联剂表面处理的纳米SiO2制备的LLDPE/纳米SiO2复合材料进行了对比。结果表明，纳米SiO2对LLDPE具有一定的增强，增韧作用；复合材料的贮能模量和损耗模量随SiO2含量的增加而增大，阻尼在-15-30℃范围内逐渐降低；复合材料的红外吸收能力较LLDPE明显提高，不同的分散，表面处理方法对纳米SiO2在基体中的分散性能影响不同。仅填加3份纳米SiO2时，常规分散，表面处理方法比基体树脂的红外吸收性能提高了42.5%。超声波分散，偶联剂表面处理方法比基体树脂提高了106.7%。     

聚合物复合材料中的纳米杂化串晶研究

聚合物纳米复合材料界面结晶处常形成纳米杂化串晶(NHSK)。文章综述了近年来纳米杂化串晶结构的研究进展,介绍了NHSK形成的方法和影响NHSK形成和生长的因素,并对NHSK的形成机理进行了深入探究。最后,介绍了NHSK的应用,并对其发展趋势做了展望。     

纳米氮化铝填充聚四氟乙烯复合材料的性能研究

采用高速混合、冷压烧结成型的方法制备了聚四氟乙烯/纳米氮化铝（PTFE/nano AlN）复合材料,考察了nano AlN含量对复合材料结晶性能、力学性能与摩擦性能的影响,并采用扫描电子显微镜对样品磨损表面进行分析。结果表明：随着nano AlN含量的增加,复合材料的结晶度呈现先增大后降低的趋势;nano AlN可显著提高复合材料的力学性能与耐磨损性能,当其含量为4 %时,耐磨损性能与纯PTFE相比提高了2个数量级。     

Synthesis and Dielectric Properties of Polyimide-Titania Hybrid Composites

A new class of polyimide-titania (TiO₂) composites with chemical bonds between the polyimide and titania system has been synthesized by the sol–gel reaction and characterized. The hybrid composite films were obtained by the reaction of lysine-organotitane monomer, which is formulated as [(EtO)₃Ti (lysinate)]_2, followed by polycondensation with dianhyride in N-methyl-2-pyrrolidone (NMP) solution, followed by heating at 100, 200, and 300 °C. The presence of chemical bonds between polyimide (PI) and titania has great effect on the properties of polyimide films, especially on their thermal and dielectric properties. The dielectric constants of the resultant nanocomposites are lower than the usual polyimide films due to the increased free volume and less polar Ti–O–Ti groups, and can be tuned by varying the molar ratio of tetraethoxysilane (TEOT) in the feed. The polyimide units offer additional advantages of imparting thermal and mechanical strength.     

聚乙烯/纳米石墨微片导电复合材料的制备与性能研究

采用纳米石墨微片(GNP)为导电填料与线形低密度聚乙烯（PE-LLD）共混来制备导电复合材料,研究了改变GNP、表面处理剂十二烷基苯磺酸钠（SDBS）和分散剂聚乙二醇(PEG)的添加量对导电复合材料的力学性能、导电性能和热性能的影响。结果表明,GNP添加量为40份时,材料会形成导电网络,体积电阻率达到8.95×10^8 Ω·cm,继续增加GNP的添加量对材料的导电性能和力学性能影响不大;导电复合材料的最佳配方为:100份PE-LLD、40份GNP、SDBS和PEG均为GNP质量的10 %。     

PGA/PBAT复合材料的性能及应用研究

采用熔融共混法制备了一系列不同组分含量的聚乙醇酸（PGA）/聚对苯二甲酸-己二酸丁二醇酯（PBAT）复合材料,对复合材料的耐热性能、力学性能和水气阻隔性能进行了表征。结果表明,当PGA含量为80 %（质量分数,下同）时,注塑样条的拉伸强度为68.80 MPa、断裂伸长率为72.15 %、冲击强度为16.00 kJ/m²、负荷变形温度为120 °C,表明该复合材料可用于制备一次性餐具;当PGA含量为20 %时,吹塑薄膜的纵横向拉伸强度均在25 MPa以上,纵横向断裂伸长率均在600 %以上,表明该复合材料可用于生产膜袋产品;此外,随着PGA含量的增加,PGA/PBAT材料的水气阻隔性能也逐渐增加,其中含20 %PGA的PGA/PBAT复合膜的水蒸气透过率为纯PBAT薄膜的1/7。     

环氧树脂基柔性MIM电容的制备与性能研究

柔性衬底因其独特的挠曲性和延展性,能够代替传统的刚性材料来制备柔性高密度MIM电容。利用原子层沉积技术,以SU-8紫外固化的环氧树脂为衬底,制备了柔性Ta2O5 MIM电容,并对制备的器件进行了电学性能的表征。结果表明:电容器件获得了较高的电容密度,为5.1 fF/μm^2。与Si基制备的Ta2O5 MIM电容相比,环氧树脂基能够获得较低的漏电流密度和较小的电容电压系数,漏电流密度4.5×10^-6 A/cm^2,电容电压系数为975×10^-6/V^2。     

白炭黑填充氢化丁腈胶的性能研究

考察了不同品种白炭黑对过氧化物硫化的氢化丁腈胶的硫化特性,力学性能和热空气老化性能的影响。结果表明:白炭黑的品种对胶料的硫化特性影响较小,弱碱性白炭黑可以增加硫化速率,缩短硫化时间;选用的5种白炭黑的力学性能较为一致,除了江西产的白炭黑表现为拉伸强度低,100%定伸应力大,扯断伸长率小,压缩永久变形小;加入白炭黑的氢化丁腈硫化胶经150℃×72 h热空气老化后,邵尔A硬度增加5～8,拉伸强度,100%定伸应力增加,扯断伸长率降低。     

纳米金属及其复合物在固体推进剂中的应用研究进展

概述了国内外纳米金属及其不同类型复合物在固体推进剂催化降解和燃烧等领域的应用研究进展,分析了在应用中存在的技术难题以及发展前景,为该领域科研人员进一步研究开发纳米金属及其复合物提供了相应的参考。     

环氧树脂/纳米Si_3N_4复合材料的制备与性能研究

以纳米 Si_3N_4为填料制备了环氧树脂/纳米 Si_3N_4复合材料。通过透射电镜观察到,纳米粒子在有机基体中分散均匀。研究了纳米 Si_3N_4对复合材料性能的影响,结果表明,添加纳米 Si_3N_4使复合材料的力学性能增加,当改性环氧树脂/纳米 Si_3N_4为100/3(质量比,下同)时,复合材料的拉伸强度、弯曲强度、冲击强度提高幅度最大,分别提高了145%、241%、255%。此时,复合材料的击穿场强提高的幅度也达到最大,在直流电压和交流电压下,分别提高了249%、146%;但添加纳米 Si_3N_4使复合材料的介电常数和介质损耗值减小;热重分析表明,环氧树脂/纳米Si_3N_4复合材料耐热性能有明显提高。并用"核-壳过渡层"结构模型初步探讨了各项性能改善的原因。     

纳米碳黑水泥基复合材料压阻效应的若干特性研究

对纳米碳黑水泥基复合材料烘干减少内部的含水量,测定材料失水前后相应的压阻效应,研究含水量变化对材料压阻效应特性影响,试验结果表明:纳米碳黑水泥基复合材料的压阻效应具有正、负两种表现形式,材料在含水量较高或者烘干至恒重状态时为正压阻效应,而在一定含水量状态时则表现为负压阻效应;纳米碳黑水泥基复合材料加载和卸载对应的△R/R0-stress曲线不重合,材料的电阻变化率△R/R0在荷载作用下具有不可逆性,压阻效应呈现非线性特征;材料在不同应力状态下,压阻灵敏度不同,压阻灵敏度随着应力水平增大而降低,在较大的应力状态下材料的压阻出现了"迟钝"现象.     

Investigation on Physico-Mechanical Properties,Water, Thermal and Chemical Ageing of Unsaturated Polyester/Turmeric Spent Composites

Nutraceutical industrial residues are potential fillers to fabricate green or eco-friendly polymeric composite materials as they are, less costly and easily available. Attempts have been made to use turmeric spent (TS)—a nutraceutical industry waste with a high E-factor to improve need-based properties of plastics. A series of unsaturated polyester resin composites have been fabricated with different turmeric spent content viz., 5, 10, 15 and 20% w/w. The effect of amount of filler content on tensile strength, physical properties including density and surface hardness and chemical resistance of the composites were determined. The influence of water and thermal ageing on the tensile strength of turmeric filler loaded unsaturated polyester composites has been studied.     

Properties of Glass-Fiber Hybrid Composites: A Review

This paper provides a rigorous literature review in a field of glass-fiber composites. Glass-fiber composite is a type of fiber-reinforced polymer composites. Glass-fiber composite holds good properties such as low density, high strength, and easy processing, so widely used in aerospace, automotive, and construction. Fabrication of glass-fiber composite has been discussed in the present study. Combining the glass-fiber with other fibers into a single polymer matrix results in the development of hybrid glass-fiber composites. The hybridization in glass-fiber composites raised new ideas for future in the field of composites.     

混杂纤维复合材料阻尼性能的研究

为了使材料具有优异的力学性能，同时能对其阻尼性能进行设计，本文讨论了混杂纤维复合材料配方、铺层设计、外界温度、频率等对材料阻尼性能的影响。采用声频内耗仪和扭摆强迫共振测试材料的阻尼值，研制出适合于鱼雷螺旋浆使用的具有吸声减振的复合材料。