共查询到20条相似文献,搜索用时 62 毫秒
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经0.1~0.2 mol/L过氧乙酸氧化鸭毛制得再生羽毛蛋白原液,再与聚乙烯醇(PVA)共混纺丝得到再生羽毛蛋白/PVA纤维;通过正交实验分析了过氧乙酸浓度、过氧乙酸溶解温度、超声波处理时间、再生蛋白与PVA质量比4个因素对纤维性能的影响.结果表明:在过氧乙酸浓度为0.15 mol/L,过氧乙酸溶解温度为60℃,超声波... 相似文献
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对挤出吹塑过程的三个阶段:型坯成型、型坯吹胀以及制品冷却与固化阶段的实验方法和装置的研究现状进行了详细论述。 相似文献
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为降低陶瓷坯体内部应力,采用ANSYS CFX对泥料挤出成型过程进行数值模拟,确定定型段长度,进口压力,含水率,挤出锥角为主要影响因素.通过对上述4个因素进行正交试验设计与分析,得出影响挤出坯体内应力状态的因素由主到次依次为定型段长度,进口压力,含水率,挤出锥角,并得到影响因素的最优组合方式.经优化后数值模拟结果可知,挤出坯体已达到较优应力状态和稳定一致的挤出速度. 相似文献
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利用正交设计方法对生产高透明聚丙烯片材的工艺条件进行试验设计,考察了机头加工温度、中辊温度及包辊时间对PP片材透明度的影响。结果表明,口模温度250℃、包辊时间15s、中辊温度55℃为生产高透明PP片材的最佳工艺参数,所得片材的雾度只有13.2%,属高透明产品。 相似文献
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以1,6己二醇二丙烯酸酯(HDDA)为接枝单体,苯乙烯(St)为共聚单体对聚丙烯(PP)进行熔融接枝,并在反应体系中加入β成核剂,从而改变PP晶型,通过接枝长支链提高聚丙烯的熔体强度。研究了螺杆转速、引发剂用量、单体摩尔比及投料量对熔体流动速率和熔体强度的影响。采用傅里叶变换红外光谱仪、热重分析仪及X射线衍射仪等对改性材料的结构和性能进行分析。结果表明,在优化的反应条件下,接枝改性PP的熔体流动速率和熔体强度分别为0.70 g/10 min,10.00 kPa·s;热稳定性也比纯PP有很大程度提高。 相似文献
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Quazi M. I. Huque Rafiqul Islam Md. Minhajul Islam Taslim Ur Rashid Sanjida Afrin Md. Asaduzzaman 《Polymer-Plastics Technology and Engineering》2013,52(2):116-121
Hybrid composites from rayon fibers (~2–5 cm size) and polypropylene (PP) were fabricated by using an extruder. Fibre content of the composite was varied from 5–30% by weight and physico-mechanical properties of the composites were measured. Surface morphology as observed by SEM showed good interface adhesion between rayon and PP matrix. Furthermore inclusion of rayon (up to 15% fiber inclusion) in the composite increased tensile, bending and hardness properties. As the fiber content in the composite increased more than 15%, physico-mechanical properties decreased due to the decrease of fiber matrix adhesion. The change of tensile properties due to environmental aging was carried out by keeping the composite under soil for 1 month and tensile properties were measured periodically. The aging result suggests that composites retained about 75% of its original tensile and bending strength even after 1 month soil burial. The modified fibers were also used for the study. As such the fibers were treated with vinyl-trimethyoxysilane and methanol solution and irradiated under UV before being used with PP in extruder. The results showed retardation of the physico-mechanical properties for composites obtained from irradiated rayon fibers than the composites fabricated from non irradiated rayon fibers. 相似文献
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接枝过程以线型等规聚丙烯(iPP)为原料,分别采用甲基丙烯酸三氟乙酯(FA-3F)、甲基丙烯酸十二氟庚酯(FA-12F)和甲基丙烯酸十七氟癸酯(FA-17F)为接枝单体,过氧化二异丙苯(DCP)为引发剂,通过反应挤出过程制备含氟改性聚丙烯。结果表明,长链含氟单体在接枝过程中更具优势,这可能与其较高的沸点有关;含氟单体的接枝度随单体加入量和引发剂加入量的增加均呈现出先迅速增加而后增加速度变缓的趋势,接枝效率则呈现明显的先增加后减少的现象;改性后聚丙烯的分子量大幅度下降,其中长链含氟单体在获得较高接枝度的同时尚保持较高的分子量,且其分布略窄。 相似文献
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反应挤出法制备马来酸酐接枝POE 总被引:8,自引:1,他引:8
采用双螺杆挤出机反应挤出制备马来酸酐接枝乙烯-1-辛烯共聚物(POE-g-MAH)。通过红外光谱分析(FTIR)、化学滴定等方法,揭示MAH过氧化二异丙苯(DCP)及供电子体(EDS)对接枝物的接枝率(GD)、凝胶率、熔体指数(MI)的影响规律。MAH和DCP的加入使MI降低,GD增大;过量的MAH使激发态的MAH猝灭,导致能引发接枝反应的激发态MAH和大分子自由基的数量减少,从而使MI上升及GD下降。在高剪切、短停留时间的挤出机中,EDS会使接枝物的性能恶化。与传统的EPDM-g-MAH增韧尼龙相比,PA/POE-g-MAH复合材料的强度保持相当,而韧性明显提高。 相似文献
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Caroline Rondel Bénédicte Portet Isabelle Alric Zéphirin Mouloungui Jean-François Blanco Françoise Silvestre 《Journal of surfactants and detergents》2011,14(4):535-544
A pea protein isolate was hydrolyzed by a double enzyme treatment method in order to obtain short peptide sequences used as raw materials to produce lipopeptides-based surfactants. Pea protein hydrolysates were prepared using the combination of Alcalase and Flavourzyme. The influence of the process variables was studied to optimize the proteolytic degradation to high degrees of hydrolysis. The average peptide chain lengths were obtained at 3–5 amino acid units after a hydrolysis of 30 min with the mixture of enzymes. Then, N-acylation in water, in presence of acid chloride (C12 and C16), carried out with a conversion rate of amine functions of 90%, allowed to obtain anionic surfactant mixtures (lipopeptides and sodium fatty acids). These two steps were performed in water, in continuous and did not generate any waste. This process was therefore in line with green chemistry principles. The surface activities (CMC, foaming and emulsifying properties) of these mixtures were also studied. These formulations obtained from natural renewable resources and the reactions done under environmental respect, could replace petrochemical based surfactants for some applications,. 相似文献
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以EGMA为增容剂,LLDPE为增韧剂,通过反应挤出技术制备了聚对苯二甲酸丁二醇酯(PBT)合金,研究了PBT合金的力学性能、热性能和微观形态结构。结果表明:PBT合金具有独特的应力-应变曲线,即没有明显的屈服应力峰。加入EGMA后,PBT的结晶度降低,分散相平均粒径尺寸减小,并且随着EGMA含量的增加,PBT合金的冲击强度显著增加,这是由于EGMA与PBT的端基发生反应生成接枝聚合物,增强了基体PBT与分散相LLDPE的界面黏结力,改善了体系的相容性。 相似文献