共查询到18条相似文献,搜索用时 156 毫秒
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采用化学发泡法,在普通注塑机上制备了聚丙烯(PP)/木粉复合发泡材料,考察了发泡剂偶氮二甲酰胺(AC)、相容剂马来酸酐接枝聚丙烯(PP-g-MAH)和木粉含量对PP/木粉复合发泡材料的力学性能、断面微观结构及表观密度的影响。结果表明,当AC含量为1.2份时,复合材料的发泡效果最好,冲击强度达到最大值20.23 kJ/m2;当PP-g-MAH含量为15份时,显著改善了木粉和PP界面之间的相容性,同时提高了复合材料的力学性能和发泡效果;木粉含量过高时,复合材料的表观密度变大,力学性能下降,发泡效果变差,当木粉含量为30份时,复合材料的各项性能较好。 相似文献
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采用超临界二氧化碳作为发泡剂,用自制的高压反应釜,在一定温度、压力和保压时间等工艺条件下,探讨经预处理的木粉对高熔体强度聚丙烯(PP)/木粉发泡材料发泡性能的影响。当木粉用量为4份时,PP/木粉发泡材料发泡性能最佳,其发泡倍率最大,为12.6倍,表观密度最小,为0.069g/cm~3,泡孔平均直径为79μm。在木粉用量为4份基础上,研究乙烯–辛烯共聚物(POE)用量对PP/木粉/POE发泡材料发泡性能的影响。结果表明,当POE用量为15份时,得到最佳发泡性能的PP/木粉/POE发泡材料,其发泡倍率最大,为14.8倍,表观密度最小,为0.06g/cm~3,泡孔平均直径为174μm,泡孔分布最均匀。 相似文献
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采用化学发泡法,用热塑性聚氨酯(PUR–T)及偶氮二甲酰胺(AC)/Na HCO3,AC/尿素及4,4’–氧代双苯磺酰肼(OBSH)/Na HCO3,OBSH/尿素复合发泡剂和交联剂甲苯二异氰酸酯(TDI)制备出交联型PUR–T发泡材料,通过万能电子试验机、发泡倍数和扫描电子显微镜分析比较了不同复合发泡剂的发泡效果,探讨了AC/Na HCO3用量配比和TDI用量对PUR–T发泡材料力学性能、发泡倍数和泡孔结构的影响。结果表明,AC/Na HCO3复合发泡剂对PUR–T的发泡效果最佳,泡孔均匀细密且结构最为稳定;当AC和Na HCO3用量均为0.2份、TDI用量为1.2份时,发泡剂的发泡速率和PUR–T的交联速率最匹配,发泡倍数为1.421倍,发泡效果最佳,制得的PUR–T发泡材料的力学性能最好,其拉伸强度达11.23 MPa,断裂伸长率达311%。 相似文献
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模压法制备发泡聚丙烯的研究 总被引:3,自引:1,他引:2
主要以聚丙烯(PP)为基体,过氧化二异丙苯(DCP)为交联剂,二乙烯基苯(DVB)为助交联剂,偶氮二甲酰胺(AC)为发泡剂,采用化学交联法,使PP在发泡之前交联,并利用模压法制取了泡孔均匀细密的泡沫板材.结果表明,当DCP含量为0.16份、DVB含量为2.00份、AC含量为2.00份时,PP发泡板材的各项性能较优. 相似文献
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以偶氮二甲酰胺(AC发泡剂)、Zn O和Na HCO3复合体系作为发泡剂,采用模压发泡的方法制备高填充粉煤灰聚氯乙烯(PVC)复合发泡板材,确定复合发泡剂的最优配比及其在复合发泡板材中的最佳用量,并对其性能进行了研究。采用发气量测定、热重/差示扫描量热(TG/DSC)分析对AC发泡剂进行了改性研究,选出分解温度满足加工条件的复合发泡剂。添加不同份数的复合发泡剂制备PVC复合发泡板材,用扫描电子显微镜(SEM)分析其断面,测试板材的冲击强度及弯曲强度。实验结果表明,当AC发泡剂、Zn O和Na HCO3的配比为2∶1∶1.5时,最大发气量为213 m L/g,分解温度区间为165~177℃,满足PVC发泡板材加工。当复合发泡剂添加量为6份时,力学性能达到最佳,弯曲强度为17.63 MPa,冲击强度为21.88 k J/m2,达到国家硬质聚氯乙烯低发泡板材的标准;粉煤灰填充量高达61.16%。 相似文献
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高发泡聚丙烯材料的研究 总被引:3,自引:2,他引:1
以偶氮二甲酰胺(AC)为发泡剂,采用化学交联法,使聚丙烯(PP)在发泡之前交联以提高熔体强度,并利用模压法制备了高发泡PP材料。结果表明:当AC含量为2份时,PP泡沫材料的表观密度降到0.2×103kg/m3,泡孔微观形态良好,但泡沫材料力学性能较差。 相似文献
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采用热重分析仪和示差扫描量热分析仪研究了偶氮二甲酰胺(AC)、N,N′-二亚硝基五次甲基四胺(H)、4,4′-氧代双苯磺酰肼(OBSH)、NaHCO34种发泡剂的分解特性。发现发泡剂AC与H的分解具有较强的突发性,发泡剂OBSH的突发性较弱,NaHCO3分解的突发性最弱。发泡助剂可以明显地降低发泡剂的分解温度,但是对发泡剂分解的突发性影响不大。发泡剂单独使用时以OBSH为最佳;复配使用时,当AC和H以2∶1的质量比使用时,效果最佳。以添加质量比为2∶1的AC和H复配发泡剂A为研究对象时,丁腈橡胶(NBR)发泡制品密度随发泡剂量的增加而逐渐减小,且当其用量超过12质量份时,密度减小的幅度变小。 相似文献
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在考察了氧化锌(ZnO)对偶氮二甲酰胺(AC)发泡剂分解温度影响的基础上,研究了AC发泡剂及辅助发泡剂碳酸氢钠(SBC)用量对材料发泡密度的影响。结果表明,发泡剂AC用量为1.0份(质量份,下同)、SBC为0.5份、ZnO为0.1份时,材料泡孔结构良好,密度较小。 相似文献
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Relatioships between the density of foamed rigid PVC/wood‐flour composites and the moisture content of the wood flour, the chemical foaming agent (CFA) content, the content of all‐acrylic foam modifier, and the extruder die temperature were determined by using a response surface model based on a four‐factor central composite design. The experimental results indicated that there is no synergistic effect between teh CFA content and the moisture content of the wood flour. Wood flour moisture could be used effectively as foaming agent in the production of rigid PVC/wood‐flour composite foams. Foam density as low as 0.4 g/cm3 was produced without the use of chemical foaming agents. However, successful foaming of rigid PVC/wood‐flour composite with moisture contained in wood flour strongly depends upon the presence of all‐acrylic foam modifier in the formulation and the extrusion die temperature. The lowest densities were achieved when the all‐acrylic foam modifier concentration was between 7 phr and 10 phr and extruder die temperature was as low as 170°C. 相似文献
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Silicone rubber foam was prepared through crosslinking with electron beam irradiation and foaming by the decomposing of blowing agent azobisformamide (AC) in hot air. The crosslinking and foaming of silicone rubber was carried out separately, which was different from the conventional method of chemical crosslinking and foaming. After foaming, the silicone rubber foam was irradiated again to stabilize the foam structure and further improve its mechanical properties. The effects of irradiation dose before and after foaming, and the amount of blowing agents on the structure and properties of silicone rubber foam were studied. The experimental results show that with the increase of AC content, the average cell diameter of silicone rubber foam increases a little, the foam density decreases to a minimum value when AC content is 10 phr. With the increase of irradiation dose before foaming from 10 to 17.5 kGy, the cell nucleation density of silicone rubber foam increases, the average cell diameter decreases, and the foam density increases. With the increase of irradiation before foaming, the tensile strength, tensile modulus, and the elongation at break of the silicone rubber foam increase. Through irradiation crosslinking again after foaming, the foam density is decreased and the mechanical properties of silicone foam are further improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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