不同无机粒子对不饱和聚酯树脂浇注体强度的影响

本文选用400目磨碎玻纤粉、滑石粉及纳米二氧化硅(SiO2)作填料,研究了这些填料的加入对不饱和聚酯树脂浇注体弯曲强度及冲击强度的影响。结果表明,树脂中加入经偶联剂处理过的磨碎玻纤粉,随着填料含量的增加,其弯曲强度先下降而后增加,而冲击强度单调增加;当上述体系中再添加纳米SiO2后,除了冲击强度在纳米SiO2加入1%时略有增加外,其它的强度值均下降;和玻纤粉相比,当树脂中加入30%的滑石粉后,树脂浇注体的冲击强度比含30%玻纤粉的浇注体略有提高,但弯曲强度却略有降低。     

短切玻纤对硬质聚氨酯力学性能和形态结构的影响

采用一步法制备了玻纤增强硬质聚氨酯的复合材料(RPU).与长径比为20和100的玻纤相比,长径比为40的玻纤增强材料的弹性模量增加了55%,而前者增强材料的弹性模量仅分别提高38.7%和41.7%;该材料增强的压缩弹性模量与拉伸弹性模量规律几乎一致.SEM图表明:适宜长径比的纤维本身的拉伸强度对于硬泡塑料的力学性能增强起了重要作用.     

长径比不同的玻纤对硬质聚氨酯的形态结构和力学性能的影响

采用一步法制备了玻纤增强硬质聚氨酯的复合材料(RPU),研究了不同长径比的玻纤对硬质聚氨酯力学性能的影响.结果表明,玻纤的长径比不同,其对RPU的增强效果差异显著.以长径比为20~40玻纤所制备的材料的拉伸强度为最大,当其质量分数为10%,拉伸强度为0.80 MPa,与未增强的材料相比提高了95%.当其质量分数为5%时,压缩强度增加了10%.SEM分析揭示样品的形貌旱球形泡孔.从拉伸端口的形貌可看出长径比为20~40玻纤受力痕迹明显,表明纤维本身的拉伸强度对于硬泡塑料的力学性能增强起了重要作用.     

磨碎玻纤对聚氨酯弹性体复合材料力学性能的影响

利用一步法制备了磨碎玻纤聚氨酯弹性体复合材料。详细探讨了磨碎玻纤用量对复合材料的拉伸强度、硬度、断裂伸长率、流动性等性能的影响。结果表明,经过有机处理的磨碎玻璃纤维对弹性体有增强增韧作用,尤其玻纤质量分数为15%时,综合效果最好。     

芦苇纤维/聚氯乙烯复合材料的研究

采用芦苇纤维填充聚氯乙烯,研究了芦苇纤维预处理、芦苇纤维用量及粒径对复合材料性能的影响。发现对芦苇纤维进行碱处理、偶联剂处理可提高复合材料的拉伸强度,但冲击强度略有下降;芦苇纤维用量的增加、粒径增大会使复合材料拉伸强度和冲击强度下降。     

SiO2粒径对PP发泡行为和力学性能的影响

通过把改性过的不同粒径SiO2以不同用量加入到聚丙烯(PP)中,制备PP/SiO2复合材料母粒,在二次开模条件下制备微发泡PP/SiO2复合材料.通过对不同粒径的SiO2粒子对PP纳米复合材料发泡行为的影响研究,讨论了超细SiO2在聚合物微孔发泡中的作用机理,分析了超细SiO2对PP的力学性能及泡孔结构的影响规律.结果表明,不同粒径的SiO2粒子的加入都能够显著降低PP的泡孔直径和增加泡孔密度;SiO2粒子使PP的缺口冲击强度升高,发泡材料的拉伸强度低于未发泡材料的拉伸强度.     

稻壳/PP-LDPE微孔发泡木塑复合材料

考察AC发泡剂用量及稻壳粉用量对复合材料密度、力学性能及微观结构的影响,结果表明:随着AC发泡剂用量的增加,复合材料的密度降低,冲击强度先增加后降低,拉伸强度急剧降低;发泡剂用量为2.5份时,密度最低为0.90 g/cm~3,冲击强度最高为6.4 kJ/m~2.稻壳粉的加入,增加了材料的密度,降低了冲击强度和拉伸强度.综合考虑,AC发泡剂用量为2.5份,稻壳粉用量为30份,复合材料的性能较好.     

玻璃纤维增强MC尼龙复合材料的力学性能

考察了玻璃纤维增强ＭＣ尼龙（ＧＦＲＭＣＮ）中玻璃纤维的表面处理及加入量对力学性能的影响。并用ＳＥＭ对ＧＦＲＭＣＮ材料界面及其对力学性能的影响进行了研究。结果表明：使用ＫＨ５５０作偶联剂对ＧＦＲＭＣＮ复合材料是很有效的;当玻纤加入４０％时,拉伸强度比基体提高３２２％,拉伸模量提高１５２％,弯曲强度提高７４３％,弯曲模量提高了１１７％。而缺口冲击强度提高了１６２％,根据材料的制备工艺特点,玻纤的加入量以３０％～４０％为宜,既保证有良好的综合力学性能,又具有很好的工艺操作性。     

木粉粒径对木塑复合材料性能的影响

采用不同粒径的木粉填充高密度聚乙烯制备木塑复合材料，研究了木粉粒径对木塑复合材料力学性能和加工流动性的影响。结果表明：木粉粒径对复合材料性能的影响十分明显，较大粒径的木粉有利于复合材料弯曲性能和冲击强度的提高。木粉粒径从100μm增加到850μm，复合材料弯曲强度增加10．4％，弯曲模量增加56．3％，冲击强度增加14．6％。随木粉粒径的增大，拉伸强度呈现先上升后下降的趋势，在200μm时出现最大值。木粉粒径对熔体流动速率（MFR）和密度的影响十分明显，大粒径的木粉使复合材料具有较高的MFR和较低的密度。     

高性能防火泡沫硅橡胶的制备

以甲基乙烯基硅橡胶制备的混炼胶为基胶,玻纤粉为成瓷填料,铂配合物为催化剂,并加入含氢硅油,通过硅氢加成反应进行硫化,同时通过硅氢脱氢反应进行发泡,制备了高温条件下可陶瓷化的防火泡沫硅橡胶。研究了硫化温度、硫化时间、催化剂用量、含氢硅油用量、羟基硅油用量、玻纤粉用量对防火泡沫硅橡胶性能的影响。结果表明:随着硫化温度的升高,泡沫硅橡胶的硫化速率加快,硫化完成时间缩短;随着催化剂用量的增加,泡沫硅橡胶的硫化速度和发泡速度均提升,拉伸强度逐渐增加,拉断伸长率先增后减,表观密度先减后增;随着含氢硅油用量的增加,泡沫硅橡胶的泡孔由少变多、由小变大,当含氢硅油超过一定量后,泡孔会用缩小并变得均匀细密,拉伸强度逐渐下降后又小幅回升,拉断伸长率逐渐下降,表观密度先减后增;随着羟基硅油用量的增加,泡沫硅橡胶的泡孔逐渐增大,拉伸强度逐渐下降,拉断伸长率逐渐上升,表观密度逐渐下降;玻纤粉对泡沫硅橡胶具有一定的补强效果,随着玻纤粉用量的增加,泡沫硅橡胶拉伸强度逐渐增加,拉断伸长率逐渐下降,泡孔逐渐缩小,表观密度逐渐下降;较佳配方为基胶用量100 g,含氢硅油用量1 g,玻纤粉用量40 g,催化剂用量2.85×10~(-6),硫化温度240℃,硫化时间5 min,此条件下制得的泡沫硅橡胶经过1 000℃灼烧30 min后,陶瓷化效果良好,无表面裂纹,质地坚硬,泡孔结构保持完整,体积保持率在85%以上,防火性能优良。     

纳米二氧化硅改性硬质聚氨酯泡沫塑料的研究

采用浇注成型法合成密度为250 mg/cm3的纳米SiO2改性硬质聚氨酯泡沫塑料(PUR-R),研究了纳米SiO2含量及偶联剂处理对纳米SiO2改性PUR-R的各种力学性能的影响。结果表明:直接使用纳米SiO2,可使PUR-R的某些力学性能得到提高,而偶联剂处理可进一步改善纳米SiO2对PUR-R的增强作用,用偶联剂改性过的纳米SiO2增强PUR-R与纯PUR-R相比,除断裂伸长率降低外,其他力学性能如拉伸强度、压缩强度、弯曲强度、冲击强度及弯曲模量等均有所提高。     

Mechanical and dynamic mechanical properties of epoxy syntactic foams reinforced by short carbon fiber

Epoxy syntactic foams were prepared with diglycidyl ether of bisphenol‐A (DGEBA) epoxy resin, 2.4.6‐tri(dimethylaminomethyl)phenol (DMP‐30), coupling treated microsphere and short carbon fiber. The density of the foam was maintained between 0.56 and 0.91 g/cm³ for all compositions. Compressive, flexural, tensile and dynamic mechanical properties of the foams were investigated with respect to hollow glass microsphere (HGM) and carbon fiber (CF) content. A considerable improvement in the mechanical properties viz. compressive, flexural and tensile strengths was observed for the foams on incorporation of a small quantity of CF. The storage modulus were higher for the foam composites containing CF. The presence of HGM has significant influence on T_g of the syntactic foams, spherical filler diminished the T_g of the syntactic foams due to the plasticizing effect of the coupling treatment of HGM, that is helpful for enhancing damping properties of syntactic foams. POLYM. COMPOS., 37:1960–1970, 2016. © 2015 Society of Plastics Engineers     

硅烷偶联剂改性云母粉在微孔发泡PP中的应用

通过硅烷偶联剂改性的云母粉,以不同含量加入聚丙烯(PP)中,制备微发泡PP/云母粉复合材料;通过相容性和分散性分析了改性与未改性云母粉微发泡PP复合材料发泡行为和力学行为的影响规律。结果表明:改性云母粉的微发泡PP复合材料泡孔直径明显减小,泡孔密度增大;抗拉强度和冲击强度都得到提高。     

玻纤增强PPS/MgO绝缘导热复合材料的研究

通过双螺杆挤出机将聚苯硫醚(PPS)与MgO混合挤出,同时添加玻璃纤维(GF)挤出造粒制备了玻纤增强PPS/MgO绝缘导热复合材料。研究了材料的导热性能与MgO含量的关系。研究发现,材料的热导率随MgO含量的增加而增大;GF替代部分MgO后,导热性能有所降低,但拉伸强度和冲击强度等力学性能得到提高;偶联剂用量在0.5%时可提高PPS/MgO绝缘导热复合材料的热导率。     

固化压力对PMI泡沫/高温固化环氧碳纤维夹层复合材料胶接性能影响的研究

针对PMI泡沫/环氧碳纤维夹层结构复合材料的热压罐胶接成型工艺,系统研究了不同密度的PMI泡沫在0.2 MPa与0.3 MPa下的热稳定性能、蠕变性能。同时分别考察了不同厚度、不同处理条件的PMI泡沫在热压罐中的压缩变形情况,总结了压力对泡沫的尺寸稳定性的影响规律。通过研究PMI泡沫/环氧碳纤维夹层结构复合材料的力学性能,比较了不同固化压力下PMI泡沫与碳纤维面板胶接质量。结果表明,密度大的泡沫的抗蠕变性能好。泡沫的高温蠕变性能受压力影响敏感,随着压力增大,变形量迅速增大。经130℃热处理2 h后PMI泡沫的抗蠕变性有所提高。采用0.2 MPa与0.3 MPa胶接的PMI泡沫/高温固化环氧碳纤维阶层结构的抗滚筒剥离强度差别较大。抗剪切强度、抗平面拉伸强度及抗弯曲强度无明显差别。     

基于大豆蛋白的高回弹聚氨酯泡沫塑料的制备及性能研究

以大豆分离蛋白、高活性聚醚、聚合物多元醇、交联剂、发泡剂、泡沫稳定剂和混合异氰酸酯为原料,自由发泡、常温熟化制备了大豆蛋白基高回弹聚氨酯软泡。研究了大豆蛋白质(SPI)对聚氨酯泡沫物理性能、力学性能、孔结构和热性能的影响。结果表明:SPI添加量对泡沫物理和力学性能影响最大。随着SPI含量增加,泡沫的密度、尺寸稳定性提高,压陷硬度和舒适因子提高增大;回弹率下降,断裂伸长率减小,而拉伸强度先增大后减小。SPI能够提高聚氨酯的热稳定性,但最好低于150℃使用。     

Flame retardant,thermal, and mechanical properties of glass fiber/nanoclay reinforced phenol–urea–formaldehyde foam

To increase the toughness, flame retardancy, and compression strength of phenolic foams, glass fiber/nanoclay composites were prepared, and their mechanical property, cellular structure, thermal stability, and flame retardancy were investigated. The results show that the pulverization rate of phenolic foam decreases significantly by adding glass fibers and nanoclay. The impact strength of the composite foam significantly increases with increasing quantities of glass fiber and nanoclay, while the compression strength of the composite foam first increases and then decreases. The microstructure of the composite foam indicates that excessive glass fiber increases the number of open cells, while an appropriate quantity of nanoclay can control the cell size. Further, excessive clay increases the thickness of cell walls and the percentage of open cells. Nanoclay increases the thermal stability of the composite foam; this decreases the maximum heat release rate, total heat release, and total smoke release of the foam, thus reducing its fire hazards. Glass fiber and nanoclay demonstrate good synergistic effects and significantly increase the compression strength, thermal stability, and flame retardancy of the foam. Moreover, the addition of nanoclay and glass fiber–nanoclay decreases the average aperture of the cells. POLYM. COMPOS., 37:2323–2332, 2016. © 2015 Society of Plastics Engineers     

长玻纤增强尼龙66复合材料性能的研究

在自制装置中用硅烷偶联剂KH550对长玻纤(LGF)进行表面处理后,采用熔融共混法制备了尼龙66/长玻纤复合材料。采用微机全自动热膨胀系数测定仪记录了玻纤增强尼龙66复合材料的热膨胀曲线,分析了玻纤含量、温度对复合材料热膨胀系数的影响,结果表明,随着玻纤含量的增加,复合材料的热膨胀系数显著下降,最大降低了74.2%;随着温度的升高,复合材料的热膨胀系数先增大后减小最后趋于平衡,转折温度在37℃左右。测试了复合材料的力学性能,结果显示复合材料的拉伸强度、弯曲强度和缺口冲击强度随玻纤含量的增加而大幅度提高,最大分别增加了173%、186%和283%。通过扫描电镜观察到玻纤嵌入尼龙66基体中,与尼龙66形成了良好的界面黏结。     

Effect of E-glass Fibers and Phlogopite Mica on the Mechanical Properties and Dimensional Stability of Rigid PVC Foams

In this work, short E-glass fibers and mica were used to enhance the dimensional stability and mechanical properties of extruded rigid polyvinyl chloride foams. Experimental results show that the dimensional stability increased by 50%, and heat resistance of the polyvinyl chloride foam improved as the amount of reinforcing solids increased in the composites. The storage modulus, tensile, and flexural strengths of the composites improved by 220, 82, and 46%, respectively. Scanning electron microscope micrographs show good interaction between glass fibers and foam cells and a good dispersion and orientation of the mica flakes along the cell walls of the polyvinyl chloride foam.     

Plant oil‐based biofoam composites with balanced performance

BACKGROUND: Biofoam composites were prepared using short sisal fibers as reinforcement and acrylated epoxidized soybean oil as matrix, aiming at replacing traditional unsaturated polyester foams in structural applications. The compressive properties of the composites were examined as a function of fiber loading, fiber length and foam density. RESULTS: The foam composite with 10 phr (parts per hundred of base resin by weight) sisal fiber possessed properties similar to those of commercial unsaturated polyester foams. A study of the failure mechanism revealed that debonding between fiber and matrix was a key issue responsible for catastrophic damage of the composites. According to this finding, surface pre‐treatment of the sisal using an alkali or silane coupling agent was carried out. This brought about positive effects on interfacial interaction and compressive strength of the composites, as desired. Also, soil burial tests proved that the foam composites could be biodegraded, and the incorporated sisal fibers accelerated the biodegradation of the composites. CONCLUSION: This work shows the feasibility of making rigid biofoams from natural resources, which could be potential candidates for structural foams. Copyright © 2009 Society of Chemical Industry