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聚乙烯醇吹膜加工性能研究 总被引:9,自引:1,他引:9
研究了聚乙烯醇(PVA)吹膜加工性能。经两种不同的增塑剂复配增塑后,可明显改善其加工流动性,当复合增塑剂用量为25phr以上,PVA可以被较好地增塑,熔融塑化温度趋于定值。热性能研究表明,PVA为不完全结晶,其熔融曲线呈不规则分布。从PVA的流变性能可知,PVA熔体呈非牛顿性流体,剪切粘度随剪切速率增加而下降,并且醇解度较高的树脂,剪切粘度也较高。不同醇解度的PVA树脂,均能通过增塑改性后熔融挤出加工吹塑成膜。高醇解度PVA膜的水溶解温度高,而低醇解度PVA膜具有低温快速水解的性能。 相似文献
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聚乙烯醇(PVA)是一种性能优异的可降解包装材料,但是,其熔点与分解温度接近,在受热熔融时发生分解。改性剂能降低聚乙烯醇的熔点,延缓分解,改善PVA的热塑加工性能,但是,影响了PVA薄膜的力学性能。实验研究了增塑剂、交联剂、稳定剂等改性助剂对PVA薄膜力学性能的影响。结果表明,随着丙三醇的添加,PVA薄膜拉伸强度降低,断裂伸长率提高,当丙三醇含量增加至40%时,断裂伸长率为293.84%;当醇解度为92时,薄膜的拉伸强度为30.54 MPa;添加硼砂能提升薄膜的拉伸强度,降低薄膜的断裂伸长率;当添加1份的氯化钙热稳定剂时,减少了PVA薄膜在加工过程中的热分解,对薄膜力学性能提升幅度较大,拉伸强度和断裂伸长率分别达到27.89 MPa、250.36%。 相似文献
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采用分子复合和增塑方法改性聚乙烯醇(PVA)1799,在单螺杆挤出机和自行设计的吹塑装置上实现了PVA的挤出吹塑成型,获得了均匀透明的PVA吹塑管坯。研究了改性PVA的热性能及改性剂含量对PVA吹塑管坯汽油阻隔性能的影响,并比较了PVA与HDPE吹塑管坯的汽油阻隔性。结果表明:改性剂的加入,削弱了PVA自身强氢键,抑制了其结晶,降低了其熔点,有利于其熔融加工,但降低了PVA吹塑管坯的汽油阻隔性;经后处理除去部分改性剂后,PVA吹塑管坯汽油阻隔性提高,明显优于HDPE,具有广阔应用前景。 相似文献
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向聚乙烯醇(PVA)中添加增塑剂、适量的加工稳定剂来改善其加工黏度,同时用DSC、IR和流变仪对改性后的PVA进行表征,发现改性剂甘油能有效地降低PVA的熔点,加工稳定剂硬脂酸锌能很好地降低PVA的加工黏度,并且还能一定程度上提高PVA的机械性能。 相似文献
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润滑剂TAF对玻璃纤维增强PBT复合材料性能的影响 总被引:1,自引:0,他引:1
采用熔融共混方法制备了润滑剂(TAF)(N,N′-双乙撑硬脂肪酸酰胺的改性产品)和玻璃纤维增强PBT复合材料,研究了润滑剂TAF对玻璃纤维增强PBT复合材料的玻璃纤维外露和性能的影响,结果发现,适量的TAF可以减少树脂粒子之间、树脂熔体与加工设备之间的相互摩擦,降低共混物在加工过程中的粘度,从而起到润滑作用,使玻璃纤维外露现象明显改善;同时也使PBT/玻璃纤维复合材料的性能发生了变化,具体表现为低分子TAF的加入使体系的冲击性能提高,拉伸强度降低,PBT的结晶温度也有所降低。结果表明,添加1%的TAF可以很好地改善玻璃纤维外露现象,使冲击强度提高近10%,而弯曲强度几乎保持不变。 相似文献
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聚乙烯醇改性及吹膜技术研究 总被引:17,自引:1,他引:17
研究了聚乙烯醇(PVA)改性及吹膜技术。经改性剂改性前后的IR分析结果表明,改性剂与PVA分子间发生了强烈的相互作用,并形成了较强的分子复合键。改性PVA塑化温度的研究表明,醇解度为88%的PVA,随相对分子质量的增加塑化温度升高。醇解度升高时,PVA塑化性能下降;改性剂用量增加,塑化温度下降。吹膜工艺研究表明,成膜助剂的加入能明显改善改性PVA的加工流动性,PVA膜对冷却效果要求较高,吹膜后的热定型处理能降低其吸湿性,延长水溶时间。 相似文献
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Yang Zhao Guiji Chen Min Xiao Shuanjin Wang Yuezhong Meng 《Journal of Polymer Research》2016,23(4):80
Biodegradable films of poly(propylene carbonate)/poly(vinyl alcohol)-thermoplastic polyurethane [PPC/(PVA-TPU)] ternary blends were successfully prepared by melting blending method. The mechanical properties of poly(propylene carbonate) blown film were greatly improved by blending PPC with PVA-TPU. In order to afford the melt processing of PVA, the PVA-TPU binary blend was firstly prepared using thermoplastic polyurethane as a polymeric plasticizer. The rheological behavior, mechanical properties and morphology of these blends were studied. Considering its melt viscosity and thermally processing temperature, the PVA-50%TPU, as a modifier, was blended with PPC to prepare PPC/(PVA-TPU) ternary blend. SEM observation revealed a basic one-phase morphological structure with very good interfacial adhesion between the extremely blurred PPC and PVA-TPU two components. Meanwhile, the miscibility of the ternary components was verified by only one glass-transition temperature obtained from DMA tests. The tensile strength and tear strength of PPC/(PVA-TPU) blown films were determined at different temperatures. The results demonstrate that the mechanical properties of PPC/(PVA-TPU) films were enhanced dramatically at low temperature when compared with neat PPC. At room temperature, PPC/30 %(PVA-50%TPU) blown film exhibited a tensile strength of 26 MPa, and an elongation at break of 484.0 %. Its tear strength in the take-up direction is 124.1 kN/m, and the one in machine direction is 141.9 kN/m. At a low temperature of 0 °C, PPC/30 %(PVA-50%TPU) exhibited a tensile strength of 40.7 MPa and tear strength of 107 kN/m, which are 153 % and 142 % of those of neat PPC respectively. The blending of PPC with the PVA plasticized with TPU provides a practical way to extend the application of the new biodegradable polymer of PPC in the area of blown films. 相似文献
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采用溶液共混的方式制备聚乙烯醇/锑搀杂二氧化锡(PVA/ATO)纳米复合材料,采用红外光谱(FTIR)、差示扫描量热仪(DSC)、光学显微镜、扫描电镜对复合材料的结构及微观形态进行了表征,对复合材料的导电性能及机械性能进行了测试。结果表明:PVA与ATO之间在共混膜中存在强烈的相互作用,这种相互作用可使纳米ATO在PVA基体中分散良好,在ATO含量较低的情况下就可获得导电性能及机械性能良好的复合材料;纳米ATO明显的异相成核效应,能够提高PVA的结晶温度及熔融温度。 相似文献
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Starch/polyvinyl alcohol (PVA) blend films were prepared by using corn starch, polyvinyl alcohol (PVA), glycerol (GL), and citric acid (CA) as additives and glutaraldehyde (GLU) as crosslinking agent for the mixing process. The additives, drying temperature, and the influence of crosslinker of films on the properties of the films were investigated. The mechanical properties, tensile strength (TS), elongation at break (% E), degree of swelling (DS), and solubility (S) of starch/PVA blend film were examined adding GL and CA as additives. At all measurement results, except for DS, the film adding CA was better than GL because hydrogen bonding at the presence of CA with hydroxyl group and carboxyl group increased the inter/intramolecular interaction between starch, PVA, and additives. CA improves the properties of starch/PVA blend film compared with GL. TS, % E, DS, and S of film adding GLU as crosslinking agent were examined. With increasing GLU contents, TS increases but % E, DS, and S value of GL‐added and CA‐added films decrease. When the film was dried at low temperature, the physical properties of the films were clearly improved because the hydrogen bonding was activated at low temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2554–2560, 2006 相似文献
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黄庄丽 《现代塑料加工应用》1992,4(1):39-41
研究在普通吹膜设备上,用聚烯烃或EVA共聚物为基材来吹塑特种泡沫薄膜,指出了发泡剂、活化剂以及温度控制对发泡状态的影响,证明了只要严格控制温度,按照“高速低温”的原则,采用适宜的配方就能够在普通的吹膜设备上顺利进行薄膜的吹塑。 相似文献
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利用除草地膜在加工冷却过程中内外壁存在的温度差,通过加入成核剂的方法改变膜两面不同的结晶结构,达到单面渗透的效果;研究了不同成核剂及用量对单渗透膜的力学性能和光学性能的影响。采用恒温水浴锅和超声波的方法萃取膜中的乙草胺,用气相色谱测定其含量;用原子力显微镜和X衍射表征了单渗透除草膜的内外壁硬度及结晶度的变化。结果表明:除草膜中山梨醇类成核剂含量在0.2%时单面渗透量由51.7%提高到75.4%,拉伸强度由15.14MPa提高到25.73MPa,而且光学性能也得到明显提高。恒温水浴锅萃取法在温度较高时薄膜易溶解,温度较低时萃取时间长效果不好,而超声波萃取法在常温下25分钟即可全部萃取出乙草胺。 相似文献