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玻璃纤维增强HDPE熔体流变性能研究 总被引:1,自引:0,他引:1
采用毛细管式流变仪研究了不同温度条件下玻璃纤维(以下简称玻纤)增强HDPE复合材料熔体的流变性能,及其与材料界面粘结性、玻纤含量等的关系。实验结果表明:材料界面粘结强度越大,玻纤含量越高,熔体表观粘度对温度的敏感性减弱,对剪切速率的敏感性则增强。对该类材料的成型应选择稍高的加工温度及剪切速率较为适宜。 相似文献
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耿丽丽;任亮;韩业;张明耀;张会轩 《中国塑料》2011,25(3):29-33
采用种子乳液聚合方法,合成一系列苯乙烯-丙烯腈共聚物接枝聚丙烯酸丁酯(PBA-g-SAN)核壳接枝共聚物,将其与苯乙烯-丙烯腈共聚物(SAN树脂)熔融共混,制得ASA树脂,使用动态力学分析仪和扫描电子显微镜考察了扩径中接枝剂的含量和PBA橡胶粒径对ASA树脂性能的影响。结果表明,随着接枝剂含量的增加,PBA-g-SAN接枝共聚物的接枝率升高,当接枝剂占单体BA的3%时,ASA树脂的冲击强度达到110 J/m。ASA树脂的冲击强度随着橡胶粒径的增加先升高后降低。PBA-g-SAN接枝共聚物中PBA的玻璃化转变温度((Tg)随着接枝剂含量的增加而升高,随着PBA橡胶粒径的增加先降低后升高。当PBA橡胶粒径为92.7 nm时,橡胶粒子发生聚集,其他粒径的PBA橡胶均可较好地分散在基体中。 相似文献
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聚醚醚酮纤维的拉伸定形后处理研究 总被引:2,自引:0,他引:2
通过熔融纺丝制得聚醚醚酮(PEEK)纤维,并采用差示扫描量热仪(DSC)、声速取向测量仪、热重分析仪、单纱电子强力仪分别研究了干热拉伸及热定形处理对PEEK纤维结晶和取向、热稳定性及力学性能的影响。结果表明:随着热拉伸倍数增大,PEEK纤维取向度、结晶度增加,纤维的断裂强度增加,断裂伸长减小;PEEK纤维的热拉伸温度应选在200~240℃,热定形温度应为220~260℃;PEEK纤维的重结晶主要是在热拉伸过程中完成,热定形则进一步完善纤维的结晶结构;经过后处理,PEEK纤维的断裂强度可达到6.12cN/dtex;且具有优异的热稳定性能,热分解温度高达505℃,后处理几乎不影响PEEK纤维的热稳定性。 相似文献
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本文采用扩链手段和交联手段对PBS进行改性研究。分别选用甲苯2,4-二异氰酸酯(TDI)为扩链剂,过氧化苯甲酰(BPO)为交联剂。使用乌氏黏度计、索氏抽提器对改性体系的特性黏数和交联度进行测定;使用哈克转矩流变仪、毛细管流变仪、差示扫描量热仪、万能拉力测试机等手段测试了改性体系的加工性能,流变性能,结晶与热性能,以及力学性能等。研究了扩链剂和交联剂用量对改性体系性能的影响。结果表明,随着TDI用量的增加,PBS改性体系的特性黏数逐渐增大,加工体系的平衡扭矩提高,熔体黏度呈现出增大的趋势,从而熔体强度增大。通过扩链反应,结晶温度提高,结晶度降低,熔点升高,拉伸强度变化不大,当TDI用量为1.0%时,拉伸强度最大。随着BPO用量的增加,PBS改性体系的交联度逐渐增大,加工性能得到改善,熔体黏度大幅提高,从而熔体强度增大。交联度的增大使得改性体系的结晶温度提高,结晶度和熔点均降低,拉伸强度呈现出先增大后减小的趋势。 相似文献
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马来酸酐接枝聚丙烯纤维的结构和性能研究 总被引:2,自引:0,他引:2
采用熔融纺丝法制备了马来酸酐(MAH)接枝聚丙烯纤维,考察了接枝纤维的力学性能和吸湿率以及马来酸酐的残留量。结果表明,马来酸酐接枝聚丙烯纤维的断裂强度比纯聚丙烯纤维的低,接枝率越高强度越低,断裂伸长率则相反;随着接枝率的增加,纤维的取向度也逐渐升高。与聚丙烯纤维相比,接枝聚丙烯纤维的吸湿率有了明显提高,在相同拉伸倍数下提高了3-5倍;MAH残留量相当于接枝率(0.73%)的3.7%,表明主要是接枝的马来酸酐改变了聚丙烯纤维的性质。 相似文献
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为了研究高温作用下玄武岩纤维混凝土的力学性能,分析不同温度作用下的混凝土(玄武岩纤维掺量分别为0、0.2%和0.4%)的物理变化,并结合单轴压缩试验,进一步研究高温对混凝土力学性能的影响。结果表明:基准混凝土与玄武岩纤维混凝土随着温度的升高,其烧失量均逐渐增加,玄武岩纤维的掺加对高温作用下混凝土水分消散阻止作用较小;表面所产生裂纹数逐渐增加,基准混凝土所产生的裂纹无论是数量还是长度与宽度均为最大。可见,玄武岩纤维在混凝土高温时所起作用主要为减少混凝土爆裂现象的产生;抗压强度均表现为先升高后降低的趋势,其中相同温度时,玄武岩纤维混凝土强度始终高于基准混凝土,且随着纤维掺量的增加而增加;由于玄武岩纤维具有较好的阻裂效果,因此当试样破坏时,玄武岩纤维混凝土破坏程度小于基准混凝土。玄武岩纤维在高温作用下主要作用为减少爆裂现象对水分蒸发的影响较小。 相似文献
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Effect of processing conditions on crystallization behavior and mechanical properties of poly(lactic acid) staple fibers 下载免费PDF全文
Within this study, the applicability of Raman spectroscopy to characterize the crystallinity of PLA staple fibers was evaluated. The influence of the fiber alignment on the possibility to detect crystallinity by using Raman spectroscopy was studied. PLA staple fibers were produced by melt spinning by varying both draw temperature and draw ratio. Systematic interrelationships between the processing parameters of PLA staple fibers and the degrees of crystallinity and the cold crystallization enthalpies were established. Raman spectroscopy showed that the carbonyl stretching band of Raman spectra measured in fiber axis and parallelly polarized was not sensitive to detect crystallinity. However, for perpendicularly polarized measurements, a higher sensitivity was observed. With increasing degree of crystallinity, a reduction of the band width of the normalized carbonyl stretching band was found. The morphology affected the mechanical properties significantly. Increased draw ratio resulted in increased tensile strength and decreased elongation at break. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42432. 相似文献
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Chaowei Hao Ying Zhao Aihua He Xiuqin Zhang Dujin Wang Qingfang Ma Yizhuang Xu 《应用聚合物科学杂志》2010,116(3):1384-1391
Fibers prepared by melt spinning process from the PP (polypropylene)/organoclay nanocomposite were characterized in details with the aid of SEM, FTIR, XRD, DSC, and mechanical measurements. The results suggested that the lower content of organoclay (0.1%) added to the PP matrix increased the crystallinity and mechanical property (tensile strength) of the PP/organoclay nanocomposite fiber. With increasing the content of organoclay (≥ 0.3%), the crystallinity and the tensile strength both a little decreased, and the fiber containing organoclay exhibited multi‐peaks at the same draw ratio during the heating process. Furthermore, the degree of orientation of the fiber increased a little with lower content of organoclay (0.1%) introduction to PP during the infrared dichroism measurement. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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以实验室自制T800级聚丙烯腈(PAN)基高强中模碳纤维为原料,经连续石墨化处理得到M50J级、M55J级高模量碳纤维,以X射线衍射(XRD)、Raman光谱为表征手段研究了高强碳纤维向高模量碳纤维转变过程中石墨微晶、取向、微孔含量、石墨化度等石墨特征结构的演变规律,并开展了PAN基碳纤维石墨特征结构与力学性能的关联性研究。研究结果表明:在高强碳纤维向高模量碳纤维转变过程中,随着石墨微晶层间距d 002的下降以及石墨微晶堆砌厚度L c的增加,碳纤维的拉伸模量逐渐提升;石墨微晶层间距和微晶取向是影响碳纤维拉伸强度的两个主要因素,石墨微晶层间距d 002值增加、石墨微晶取向越高,纤维拉伸强度也越高;在高模量碳纤维的成型过程中,纤维内部微孔含量随着石墨化程度的提高而降低;经过高温石墨化处理后,碳纤维的拉伸强度会随着Raman光谱中无序结构D峰和石墨特征结构G峰积分强度比值I D /I G的下降而下降。 相似文献
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Hindered piperidine amine (HPA) and tertiary amine (TA) were introduced into hydrolytic polymerization of caprolactam, and polyamide 6 (PA 6) modified by additives [HPA/TA = 1 : 1 (w/w)] was obtained. The effects of additives on the melt, light, and heat stability of PA 6 were studied. The results showed that with an increase in additive content, the viscosity of PA 6 increased and the elastic response decreased. Thus, the drawing property of PA 6 fibers during melt spinning was improved. With the addition of 0.1%–0.2% additives, the degree of variation in amino end group content and relative viscosity decreased during the process going from resin to fiber, indicating the modified PA 6 had improved melt stability. During light and heat aging, the ratio of retained fracture strength of PA 6 filament increased after modification by 0.1%–0.4% additives. Scanning electron microscopy showed that the surface morphology of the modified fiber remained almost the same, whereas that of the unmodified fiber was seriously destroyed when exposed to xenon light for 8 days or heated to 180°C in air for 1.5 h. The degree of variation of relative viscosity of the PA 6 fiber also decreased after modification by 0.1%–0.2% additives under oxidative degradation. All these results indicate PA 6 had better melt, light, and heat stability when modified by additives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 538–544, 2007 相似文献
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