共查询到19条相似文献,搜索用时 218 毫秒
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《高科技纤维与应用》2016,(6)
试验研究了国产对位芳纶STARAMID含水质量分数、纤维强力、表面处理剂类型、表面处理剂质量分数等对三元乙丙橡胶(EPDM)生产工艺和剥离强度的影响。结果表明,纤维含水质量分数7%,纤维强力(1 100 dtex)≥200 N,(1 870dtex)≥300 N,油剂选用初沸点高于200℃的硬脂酸类油剂,油剂质量分数为1%~2%,可满足胶管生产工艺要求,又满足胶管剥离强度2.5 k N/m的要求。 相似文献
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《高科技纤维与应用》2016,(4):70-71
正本发明涉及一种热解致孔的对位芳纶纳米纤维锂离子电池隔膜的制备,属于新能源材料领域。本发明针对现有对位芳纶纳米纤维隔膜制备技术和产品的不足,通过将对位芳纶纳米纤维隔膜中的高分子表面活性剂通过烧蚀处理掉,从而实现了调控对位芳纶纳米纤维隔膜的孔径以及孔 相似文献
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为了改善对位芳纶的染色性能,采用避蚊胺N,N-二乙基-间甲基苯甲酰胺(DEET)作为分散染料(分散蓝2BLN)染色载体对对位芳纶进行载体染色,研究了DEET对对位芳纶结构、染色性能及力学性能的影响。结果表明:经DEET处理后,对位芳纶的玻璃化转变温度降低,结晶度和力学性能基本不变;对位芳纶进行分散染料高温高压载体染色,当分散蓝染料对纤维的质量分数为2%,染色温度130℃,染色时间60min,DEET浓度为4 g/L,浴比1∶20,纤维上染率高达90%以上,DEET具有良好的载体功能和促染效果。 相似文献
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《塑料工业》2021,(5)
在250℃条件下以空气氧化热处理改性芳纶纤维,通过红外光谱(FTIR)、Raman光谱、X射线衍射(XRD)、扫描电子显微镜(SEM)研究了热氧化处理时间对芳纶纤维表面基团和聚集态结构的影响。FTIR结果表明,热处理过程中纤维表面皮层分子链重排,氢键重构,100 min的热处理时间能够使纤维表层的分子链重新排列取向完成,延长处理时间对表层结晶度影响不大。XRD研究表明芳纶纤维热处理60 min后结晶度达到最大,继续延长热处理时间纤维表层的含氧量变化并不明显。芳纶纤维在250℃条件下一定时间热处理对纤维的单丝拉伸强度影响并不明显,热处理热120 min,芳纶纤维的单丝拉伸强度为24.5 cN/dtex,与原丝相比提升了约3%。250℃热处理60 min后芳纶纤维与环氧树脂微滴间界面剪切强度增加到18.05 MPa,与原丝相比增加了11.9%。 相似文献
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采用氢氧化钾(KOH)溶液对对位芳纶进行表面预处理,以硝酸银(AgNO_3)和氨水制备银氨溶液作为施镀液,利用化学镀银法制备金属化对位芳纶,研究了AgNO_3浓度和施镀时间对金属化对位芳纶的镀层形貌、导电性能及力学性能的影响,同时探讨了化学镀银过程中对位芳纶表面银(Ag)的沉积动力学过程。结果表明:通过单一变量法实验,化学施镀温度为50℃、AgNO_3浓度为0.5 g/L、施镀时间为50 min时,镀银效果好,制备的金属化对位芳纶具有良好的导电性能和力学性能;金属化对位芳纶表面的Ag层分布均匀、Ag晶粒尺寸为21.04 nm,纤维表面电阻达1.5Ω/cm、断裂强度为18.9 cN/dtex、断裂伸长率为3.9%,断裂强度比原丝仅下降8.3%,不影响纤维的使用性能;随着施镀时间的增加,金属化对位芳纶表面Ag的沉积速率显著降低、增重率逐步增加。 相似文献
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为评价聚酯工业丝在受热条件下的应用特性,模拟聚酯工业丝的受热条件,在其结构易发生转变的温度(140℃)附近进行紧张热处理,探讨了温度、时间、张力对聚酯工业丝结构性能的影响。结果表明:纤维经过热处理后,断裂强度总体变化幅度不大,但能够反映聚酯工业丝的应用特性的指标如初始模量、5%定伸长时的应力(Lase-5)、定载荷下的伸长率等指标受热处理条件影响很大。在温度较高、受热时间短、张力小的情况下,纤维内主要发生无定形区分子链的松弛,致使其初始模量和Lase-5显著降低。在延长受热时间、增加张力的情况下,利于无定形区重排为有序结构,纤维的初始模量、Lase-5和干热收缩率的下降程度减小。 相似文献
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Lyocell fibers were heat‐treated under different conditions. The tensile strength and initial modulus of the heat‐treated Lyocell fibers increased sharply, whereas the elongation at break decreased. Moreover, applying tension to the fibers during the heat treatment further improved the tensile strength and initial modulus. In addition, the crystallinity of the heat‐treated fibers increased slightly, and there was no obvious change with an increase in the tension; the general orientation of the heat‐treated fibers increased, the crystalline orientation little changed, and the amorphous orientation improved. Also, the improved mechanical properties of the Lyocell fibers via the heat treatment could not be preserved for long. The reason may be that the crystalline structure of the Lyocell fibers was not destroyed and no new crystallites were formed during the heat‐treatment process. Therefore, the heat‐treated Lyocell fibers reverted to their original state with time because there was no crosslinking point to fix the orientation, although the cellulose molecules of the amorphous region of the Lyocell fibers were more oriented by the heat treatment with tension. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1738–1743, 2006 相似文献
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Jeffery S.Downey Constantine W.Tsimpris Andrew L.Pollar Chloe F.Wilson Jocelyn Willis-Papi Christiane K.Hohenwarter Qin Lin 黎学东 《轮胎工业》2012,32(7):417-422
研究Kevlar对位芳纶浆粕和精切短纤维对天然橡胶胶料的补强效果。结果表明:随着纤维用量的增大,Kevlar对位芳纶浆粕补强的胶料储能模量增加幅度大于损耗模量增加幅度,损耗角和损耗因子随着浆粕用量的增大而降低,这种效果有利于低滚动阻力轮胎或其他轮胎部件的胶料配方设计,在提高胶料定伸模量的同时不会增加滞后生热;Kevlar对位芳纶浆粕表现出的一种独特手风琴效应可能是低滞后生热的原因。 相似文献
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利用XRD研究了PAN基碳纤维在连续高温石墨化和热牵伸石墨化过程中纤维内石墨微晶沿纤维轴择优取向性的变化。结果表明:碳纤维中石墨微晶的择优取向性随石墨化温度的提高和热牵伸的增大而增加。两种工艺中纤维的拉伸模量均随微晶取向性的增加而增大,但在获得相同的模量下其取向参数却不同;碳纤维的拉伸模量不仅仅取决于石墨微晶的择优取向,而且与晶体的大小有关。另外,经过3000℃的高温处理后,纤维的择优取向参数Z仅为14.71°,说明纤维中乱层石墨的层面仍没有高度取向。 相似文献
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研究了热定型过程中的张力对PAN原丝结构与性能的影响。结果表明:热定型张力对PAN原丝的物理性能影响很大;随着热定型张力减小,PAN原丝的抗拉伸强度和初始模量随之减小,而断裂后伸长率逐渐增大;沸水收缩率和取向度也随着定型松弛幅度的增加而降低。 相似文献
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D. M. Bigg E. G. Smith M. M. Epstein R. J. Fiorentino 《Polymer Engineering and Science》1986,26(18):1254-1263
Solid state rolling of semicrystalline polymers represents a high speed process for producing oriented, high modulus films, tapes, and sheets. The important process variables include roll temperature, thickness of initial sheet, roll speed, take-up tension, roll diameter, and initial morphological state of the polymer. Roll temperature controls both the extent of maximum deformation and the rate of rolling. A minimum temperature exists for each polymer below which the orientation process is sharply limited. This condition is similar to the limitation present in the hydrostatic extrusion process, in which the alpha crystallization temperature limits the orientation process. Roll speeds as high as 20 m/min have been realized. It is apparent that film thickness and thickness reduction ratio have a strong effect on the ultimate rolling rate. The process, as currently practiced, is adiabatic, and therefore, heat transfer limited. The take-up tension influences the extant of orientation in the amorphous phse of of the polymer. This in turn affects its thermal and chemical stability. The effect of roll diameter is to limit the extent of thickness reduction by causing roll-film slippage when the roll dianmeter to thickness reduction ratio is below some as yet undetermined value. The initial morphological state of the polymer affects the amount of crystalline deformation possible, the surface texture of the rolled film, and the tear resistant of the oriented film. 相似文献
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以高铝粉煤灰提铝硅钙尾渣为主要原料,采用烧结法制备了硅灰石微晶玻璃。利用DTA、XRD和SEM分析方法研究了热处理制度、硅钙渣用量对微晶玻璃的晶化过程、显微结构及物化性能的影响。结果表明:核化时间与晶化时间的延长有助于硅灰石晶体的定向生长与紧密排列,对微晶玻璃的力学性能影响显著,而晶化温度与核化温度的影响则相对较小;随着硅钙渣的用量增加,微晶玻璃中硅灰石的析出能力增强,当其用量为70.98%,在800℃下核化热处理90 min,920℃晶化处理90 min时,可制备出单一晶相的硅灰石微晶玻璃。 相似文献
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ABSTRACT Simultaneous heat and mass transfer equations were developed to simulate the infrared radiative heating of agricultural crops. The equations assume that moisture diffuses to the outer boundaries of the material in liquid form and evaporation occurs at the surface of the kernel. Energy for moisture evaporation is supplied by the infrared radiant energy. The equations were validated with experimental data on surface temperature and average moisture content of barley kernels. Average deviations of predicted surface kernel temperature and average kernel moisture from experimental data were 3.9°C and 0.6%(w.b.), respectively. These comparisons were performed using kernels having initial moisture contents of 12.2%, 17.C% and 23.17%. Sensitivity analysis of process parameters showed that infrared burner temperature, distance of infrared burner from the grain bed, grain initial moisture content and grain heating time significantly affected kernel temperature. Burner temperature and burner height had no significant effect on grain final moisture content. 相似文献