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.     

Improvement of Mechanical Properties of Jute Fibers-Polyethylene/Polypropylene Composites: Effect of Green Dye and UV Radiation

Jute-reinforced polyethylene (PE), polypropylene (PP) and mixture of PP/PE composites were prepared. It was found that 90% PP and 10% PE matrices based jute reinforced composites performed the better results. UV radiation at different intensities was applied both on matrices and jute. Mechanical properties of the irradiated jute- and matrices-based composites were found to increase significantly. Optimized jute fabrics were also treated with different concentrations of green dye (0.1–1%, w/w) with 2% K₂O₈S₂ in methanol solution for 2–8 min. A composite made of 0.5% green dye jute (5 min soaking time) and irradiated matrix showed the best mechanical properties.     

A Comparative Study on the Mechanical,Degradation and Interfacial Properties of Jute/LLDPE and Jute/Natural Rubber Composites

Jute fabric (hessian cloth) reinforced low-density polyethylene (LLDPE) composites (40 wt%) and solid natural rubber-(NR) based composites (40 wt%) were fabricated by compression molding. Tensile strength (TS), tensile modulus (TM) and percentage elongation at break (Eb) of jute/LLDPE composites were found to be 29, 680 MPa and 20%, and for jute/NR-based composites were also found to be 15, 122 MPa and 94%, respectively. Interfacial shear strength (IFSS) of the jute/LLDPE and jute/NR systems was investigated by using the single fiber fragmentation test (SFFT). Scanning electron microscopy (SEM) and aqueous degradation tests were also performed.     

Effects of Surface Pretreatment on the Mechanical and Dielectric Properties of Photocuring Jute Fibers

Jute fabrics were treated with ethylene glycol dimethylacrylate (EGDMA) + MeOH solutions at different proportions along with photoinitiator Irgacure 907 and cured under UV-radiation. Monomer concentration, soaking time, and radiation dose were optimized in terms of polymer loading and mechanical properties. Twenty-five percent EGDMA, 30-minute soaking time, and tenth-pass of radiation produced higher tensile strength (75%) and tensile modulus (88%) than those of the untreated sample, as well as the highest polymer loading value (70%). Among different additives used, urea showed the best performance. SEM, water uptake, and dielectric properties of the samples were studied.     

Effect of Ultraviolet Radiation on the Mechanical and Dielectric Properties of Hessian Cloth/PP Composites with Starch

Hessian cloth (jute fabrics) reinforced poly(propylene) (PP) composites (45 wt% fiber) were prepared by compression molding and the mechanical properties were evaluated. Jute fabrics and PP sheets were treated with UV radiation at different intensities and then composites were fabricated. It was found that mechanical properties of the irradiated jute and irradiated PP-based composites were found to increase significantly compared to that of the untreated counterparts. Irradiated jute fabrics were also treated with aqueous starch solution (1–5%, w/w) for 2–10 min. Composites made of 3% starch-treated jute fabrics (5 min soaking time) and irradiated PP showed the best mechanical properties. Tensile strength, bending strength, tensile modulus, bending modulus and impact strength of the composites were found to improve 31, 41, 42, 46 and 84% higher over untreated composites. Water uptake, thermal degradation and dielectric properties of the resulting composites were also performed.     

Fabrication and Mechanical Characterization of Jute Fabrics: Reinforced Polyvinyl Chloride/Polypropylene Hybrid Composites

Jute fabrics such as reinforced polyvinyl chloride (PVC), polypropylene (PP), and a mixture of PVC and PP matrices-based composites (50 wt% fiber) were prepared by compression molding. Tensile strength (TS), bending strength (BS), tensile modulus (TM), and vbending modulus (BM) of jute fabrics' reinforced PVC composite (50 wt% fiber) were found to be 45 MPa, 52 MPa, 0.8 GPa, and 1.1 GPa, respectively. The effect of incorporation of PP on the mechanical properties of jute fabrics' reinforced PVC composites was studied. It was found that the mixture of 60% PP and 40% PVC matrices based composite showed the best performance. TS, BS, TM, and BM for this composite were found to be 65 MPa, 70 MPa, 1.42 GPa, and 1.8 GPa, respectively. Degradation tests of the composites for up to six months were performed in a soil medium. Thermo-mechanical properties of the composites were also studied.     

Comparative Studies on the Mechanical,Degradation and Interfacial Properties between Jute and E-Glass Fiber-Reinforced PET Composites

Jute fiber mat (hessian cloth) reinforced PET-based composites (50% fiber by weight) and E-glass fiber matreinforced PET based composites (50% fiber by weight) were fabricated by compression molding and the mechanical properties tensile strength (TS), tensile modulus (TM), elongation at break (%), bending strength (BS), bending modulus (BM), impact strength (IS) and hardness (Shore-A) of the composites were evaluated and compared. The interfacial properties of the both composites were also compared. Water uptake test and soil degradation test were also investigated.     

Surface Modification of Jute Fabrics Using Acrylic Monomers: Effect of Additives

Jute fabrics were modified with methyl acrylate (MA), ethyl acrylate (EA), and 2-hydroxyethyl acrylate (2-HEA) using UV radiation at different periods of time. It was found that 30% MA at 60 min, 15% EA at 40 min, and 15% 2-HEA at 15 min irradiation time in methanol along with photoinitiator showed the best results. Some additives, such as urea, acrylamide (AM), ethylhexyl acrylate (EHA), tripropelene glycol diacrylate (TPGDA), and trimethylol propane triacrylate (TMPTA), were incorporated into the optimized monomer solutions and monitored its effect on the properties. Various physico-mechanical properties of both treated and untreated jute fabrics were also performed.     

Mechanical and Electrical Properties of Jute Fabrics Reinforced Polyethylene/Polypropylene Composites: Role of Gamma Radiation

Jute fabrics reinforced polyethylene (PE), polypropylene (PP) and mixture of PP+PE matrices based composites (50 wt% fiber) were prepared by compression molding. It was found that the mixture of 80% PP + 20% PE hybrid matrices based jute fabrics reinforced composites performed the best results. Gamma radiation (250–1000 krad) was applied on PP, PE and jute fabrics then composites were fabricated. The mechanical properties of the irradiated composites (500 krad) were found to increase significantly compared to that of the non irradiated composites. Electrical properties like dielectric constant, loss tangent and conductivity with temperature variation of the composites were studied.     

MWCNTs/PP多层复合膜的结构及介电性能

将不同含量多壁碳纳米管(MWCNTs)的聚丙烯(PP)薄膜,通过热压叠层复合的方法制备了MWCNTs/PP多层复合膜。利用扫描电子显微镜(SEM)和电感电容电阻测试仪(LCR)研究了MWCNTs含量和多层结构对MWCNTs/PP多层复合膜介电性能的影响。结果表明:随着MWCNTs含量和复合层数的增加,低频下介电常数得到明显提高,介电损耗增加趋缓。结合微结构的表征结果,建立了微结构-介电性能之间的关系,导电层和绝缘层的交替结构使得MWCNTs/PP多层复合膜的介电常数显著提高,介电损耗仅有微小增加。     

偶联剂对黄麻增强聚丙烯复合材料冲击强度的影响研究

文章采用塑炼机熔融共混的方法制备了黄麻纤维增强聚丙烯复合材料,用马来酸酐接枝聚丙烯作为偶联剂,制备出性能较好的聚丙烯复合材料。通过力学测试研究了复合材料的抗冲击性能。     

柠檬石膏/聚丙烯复合材料的制备与性能

研究了柠檬石膏及表面处理柠檬石膏对聚丙烯(PP)复合材料的力学性能、微观形貌、结晶度、熔点的影响。结果表明:柠檬石膏的加入使复合材料的拉伸强度、弯曲强度和弯曲模量有不同程度提高,用钛酸酯和铝酸酯偶联剂对柠檬石膏进行表面处理后效果较好。扫描电镜(SEM)分析结果显示经过偶联剂表面处理的柠檬石膏在PP中分散的较未处理的柠檬石膏均匀。差示扫描量热(DSC)结果表明:柠檬石膏的加入在提高PP的结晶度同时,对复合材料的熔点几乎没有影响;相比未表面处理的柠檬石膏,表面处理后的柠檬石膏对复合材料中PP的结晶度和熔点均没有显著影响。     

热压条件对短切SiCf/LAS复合材料介电/力学性能的影响

采用热压烧结法制备出致密度超过90%的短切SiCf增强LAS玻璃陶瓷基复合材料,讨论了热压温度与压力对复合材料性能的影响。力学测试表明,当热压温度由1200℃上升到1280℃,复合材料断裂强度从124MPa下降到80MPa,断裂韧性从3.27MPa.m1/2下降到2.92MPa.m1/2;当热压压力由20MPa提高到34MPa,复合材料断裂强度从124MPa下降到86MPa,断裂韧性从3.27MPa.m1/2下降到3.00MPa.m1/2。断口形貌SEM观察结果表明,因纤维掺入过量,φ(SiCf)=36%,使纤维与基体结合较差;而过高的热压温度与压力会使界面反应加剧,破坏纤维强度及纤维与基体的结合。介电性能测试表明,在8～12GHz频率,复合材料复介电常数的实部ε′由基体的7.6增大到10～70,虚部ε″由基体的0.34增大到60～160,介电损耗tgδ由基体的0.04增大到2～20,并具有明显的频散效应。而且,随热压温度升高或者热压压力的增加,复合材料ε′增大,而ε″与tgδ减小。复合材料具有成为电损耗型宽带微波吸收材料的潜力。     

Preparation,Characterization, and Dielectric Properties of PP/CaTiO3 Composites for Microwave Substrate Applications

Calcium titanate (CaTiO₃) filled polypropylene (PP) composites have been fabricated through compression molding method. The phase purity of the PP/CaTiO₃ composites was studied using X‐ray diffraction studies. Scanning electron microscopy technique has been employed to study the dispersion of the particulate filler in the PP matrix. The dielectric constant and loss tangent of the composites were measured at X‐band frequency region using waveguide cavity perturbation technique. PP/CaTiO₃ composite has an effective dielectric constant of 11.74 and loss tangent 0.007 at optimum filler loading. The experimental dielectric constant of filled composites was compared with theoretically predicted dielectric constant values obtained using different modeling approaches. The linear coefficient of thermal expansion of PP/CaTiO₃ composites was studied using thermomechanical analyzer.     

PP/POE/BaSO4三元复合体系力学性能研究

采用2步法工艺制备了PP／POE／BaSO4[聚丙烯／（乙烯／辛烯共聚物）／硫酸钡]、PP／POE／偶联剂处理BaSO4和PP／POE／马来酸酐处理BaSO4三元复合体系。前2种三元复合体系形成了完全分离结构，而后1种三元复合体系形成了核壳包覆结构。力学性能研究表明，具有核-壳结构的三元复合体系的拉伸屈服应力、冲击韧性大于具有完全分离结构的三元复合体系，但前者的弯曲模量与断裂伸长率小于后者。     

Effect of Sodium Bicarbonate on the Mechanical and Degradation Properties of Short Jute Fiber Reinforced Polypropylene Composite by Extrusion Technique

Short jute fibers and the pellets of polypropylene (PP) were compounded to make composites with the help of an extruder followed by compression molding. The mechanical properties of the composites increased with the increase of fiber content up to 20%, then decreased while the jute content varied from 5 to 30 wt%. Composites with varying percentages (5 to 20%) of sodium bi-carbonate at constant (20%) jute content were made by same process. The mechanical properties, soil degradation tests, and the water uptake capacity of the composites were investigated properly. Also, the density of the composite was reduced up to 21.54%.     

乙烯-甲基丙烯酸甲酯共聚物对聚氯乙烯／聚丙烯复合材料性能的影响

以乙烯-甲基丙烯酸甲酯共聚物（EMMA）为增容剂制备了聚氯乙烯（PVC）／聚丙烯（PP）复合材料．采用DSC表征了复合材料的相容性,用WDW3020微控电子万能实验机、XCJ-40电子冲击实验机测试了复合材料的力学性能;并与氯化聚乙烯（CPE）增容PVC／PP共混体系进行了比较。试验结果表明：EMMA能显著改善PVC与PP的相容性。当增容剂用量为9份时,与未增容PVC／PP体系相比。缺口冲击强度,拉伸强度和弯曲强度分别提高了191％,70％,41％;与CPE增容PVC／PP体系相比,缺口冲击强度,拉伸强度和弯曲强度分别提高了44％,39％,12％。     

PP/PP-g-GMA/EP共混物的制备与性能!

采用熔融共混的方法,制备了聚丙烯(PP)/甲基丙烯酸缩水甘油酯接枝聚丙烯(PP-g-GMA)/环氧树脂(EP)共混物,研究了固化剂4,4二氨基二苯甲烷(DDM)和相容剂PP-g-GMA对共混过程扭矩的影响,探讨了共混物的力学性能,讨论了EP固化与相容剂对共混物热稳定性与结晶性能的影响。结果表明,加入固化剂和相容剂提高了共混扭矩,加入相容剂提高了共混物的拉伸强度与模量,但降低了断裂伸长率,环氧固化与相容剂提高了共混物的最大分解速率温度和PP的结晶温度。     

HGB的表面改性对PP／HGB复合材料力学性能和结晶性能的影响

采用KH550硅烷偶联剂和硝酸钕分别对空心玻璃微珠进行表面改性;熔融共混挤出法制备PP／HGB复合材料;研究复合材料的力学性能,并采用差示扫描量热法研究PP／HGB复合材料的非等温结晶过程。利用Jeziorny方程对PP和PP／HGB复合材料进行非等温结晶动力学的研究。结果表明：未经表面改性的HGB与PP的界面结合力差,复合材料的综合力学性能较差。HGB经过KH550和硝酸钕表面改性后,提高了与PP的界面黏结力,复合材料的力学性能得以提高,并且经过KH550和硝酸钕表面改性的HGB可以小幅提高复合材料的结晶度,但降低PP的结晶速率。     

聚丙烯/n-SiO2复合材料的制备与性能研究

采用熔融共混法制备了PP/纳米SiO2复合材料,并通过力学性能测试、DSC分析以及材料断面形貌分析等手段,对增强增韧效果进行了研究。结果表明,加入纳米SiO2能提高了PP的结晶速率,使结晶度增大。当纳米SiO2的质量分数为2%时可使PP/nSiO2复合材料的缺口冲击强度提高2倍,拉伸强度稍微下降。