TPU发泡薄膜制备工艺及相关性能的研究

发布时间：2017-12-27 08:29

本文关键词：TPU发泡薄膜制备工艺及相关性能的研究　出处：《天津工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：TPU具有优异的物理机械性能,如耐磨性高、耐腐蚀性强、拉伸强度高等,其制备的发泡材料在保持TPU优异性能的同时,还具有泡沫材料的特点,如质轻、隔热、隔音、缓冲性能。发泡薄膜在新型人造革的制作和缓冲材料的制备方面很有前景,目前制备的TPU发泡薄膜材料中,密度低于0.8g/cm3且泡孔细密均匀的比较少,而且制备这些发泡薄膜材料的工艺存在一定的缺陷。本课题将AC与1#TPU通过双螺杆挤出机混炼均匀后发泡,通过改变AC发泡剂在1#TPU中的比例、发泡温度和发泡时间,研究AC对1#TPU发泡材料性能的影响,通过平均泡孔直径、泡孔个数、发泡倍率、表观密度、拉伸强度的比较,优选工艺条件。实验结果表明,当AC与1#TPU质量比为1：30,发泡温度为215℃,发泡时间为4min时达到较好的效果,泡孔直径为232μm,泡孔均匀,表观密度为0.35 g/cm3,拉伸强度为2.8MPa,拉伸强度下降30%。另外,测试了1#TPU熔体的流变性,在此基础上分析了TPU发泡过程中的表现。AC发泡剂的分解温度对于低硬度的TPU而言比较高,为降低AC的分解温度,向AC发泡剂中加入助剂尿素、碳酸氢钠、有机锌盐配置复合改性发泡剂,通过排水量气法及热重分析对比不同复合改性发泡剂的初始分解温度、突发分解温度和发气率,分析助剂对AC发泡剂分解的影响规律。经研究发现,尿素改变了AC的分解历程,降低了AC的分解温度和发气率,当AC与尿素质量比为1：0.8效果较好；碳酸氢钠降低了AC的分解温度,提高了发气率,当AC：碳酸氢钠质量比为1：0.3效果较好；有机锌盐对AC的分解过程起着活化作用,当AC：有机锌盐质量比为1：0.2时效果较好。最终得到复合改性发泡剂AC：尿素：碳酸氢钠：有机锌盐质量比为1：0.8：0.3：0.2,AC发泡剂的初始分解温度从205℃降为155℃,突发温度段从215～225℃降为165～185℃,发气率从160ml/g增加到175ml/g。基于尿素对复合改性发泡剂的影响,配置复合改性发泡剂Ⅰ和复合改性发泡剂Ⅱ,并用于不同TPU的发泡。通过DSC和熔融指数分析不同TPU的加工性能,同时对复合改性发泡剂Ⅰ和复合改性发泡剂Ⅱ做热重分析,发现复合改性发泡剂Ⅰ分解过程较缓和,分解速率慢,容易制得泡孔均匀的试样。对比复合改性发泡剂Ⅰ和复合改性发泡剂Ⅱ的发泡试样,复合改性发泡剂Ⅰ的发泡试样泡孔更加细密,拉伸强度较高,效果比较好。其中2#TPU发泡效果较好,泡孔直径为142μm,泡孔均匀细密,表观密度为0.7g/cm3,拉伸强度为1.3 MPa,拉伸强度下降40%。发泡工艺为：复合改性发泡剂Ⅰ与2#TPU质量比为1：32,发泡温度为185℃,发泡时间为1min。通过生产型螺杆挤出机进行放样试验,发现工艺稳定,重演性好,所得试样泡孔直径为140μm,泡孔均匀细密,表观密度为0.69 g/cm3,拉伸强度为1.33 MPa,拉伸强度下降36%。
[Abstract]:TPU has excellent physical and mechanical properties, such as high wear resistance, strong corrosion resistance and high tensile strength. The foamed material has excellent properties of TPU while also has the characteristics of foam materials, such as light weight, heat insulation, sound insulation and cushioning. Foamed film has great potential in the manufacture of new artificial leather and the preparation of cushioning materials. At present, the density of TPU foamed thin films is less than 0.8g/cm3 and the pores are thin and uniform. This topic will be AC and 1#TPU by double screw mixing evenly foaming extrusion machine, by changing the AC foaming agent in 1#TPU ratio, foaming temperature and foaming time, the effects of AC on properties of 1#TPU foam materials, the average cell diameter, cell number, foaming rate, apparent density, tensile strength comparison of the optimum conditions. The experimental results show that when the mass ratio of AC to 1#TPU is 1:30, the foaming temperature is 215 degrees, and the foaming time is 4min. The best effect is achieved. The cell diameter is 232 m, the pore size is uniform, the apparent density is 0.35 g/cm3, the tensile strength is 2.8MPa, and the tensile strength is reduced by 30%. In addition, the rheological properties of 1#TPU melt were tested. On this basis, the performance of TPU foaming process was analyzed. The decomposition temperature of foaming agent AC is relatively high for the low hardness of TPU, in order to reduce the decomposition temperature of AC, added to the AC foaming agent, sodium bicarbonate, urea additive in organic zinc salt configuration composite modified foaming agent, the initial comparison of different modified composite foaming agent decomposition temperature, decomposition temperature and rate of gas burst through drainage the amount of gas method and thermogravimetric analysis, to analyze the effect of AC foaming agent decomposition of additives. The study found that urea altered decomposition process of AC, reduce the temperature and rate of gas decomposition of AC, AC and urea when the mass ratio of 1:0.8 is better; sodium bicarbonate reduces the decomposition temperature of AC, improve the rate of gas, when the mass ratio of 1:0.3: AC of sodium bicarbonate is better; the decomposition process of organic zinc salt the AC plays a role when the AC activation, organic zinc salt is better when the mass ratio of 1:0.2. Finally, the compound modified foaming agent AC: urea: sodium bicarbonate: organic zinc salt mass ratio 1:0.8:0.3:0.2, AC foaming agent initial decomposition temperature decreased from 205 to 155 degrees, the burst temperature segment decreased from 215~225 to 165~185 degrees, and the gas generation rate increased from 160ml/g to 175ml/g. Based on the effect of urea on the compound modified foaming agent, a compound modified foaming agent I and a compound modified foaming agent II were arranged and used for the foaming of different TPU. The processing properties of different TPU were analyzed by DSC and melt index. At the same time, thermogravimetric analysis of composite modified blowing agent I and composite modified blowing agent II was carried out. It was found that the decomposition process of composite modified foaming agent was slower and the decomposition rate was slow, so that the samples with uniform pore size were easy to make. Compared with the foaming sample of composite modified foaming agent I and composite modified foaming agent II, the foaming sample of composite modified foaming agent I has more compact pores, higher tensile strength and better effect. The foaming effect of 2#TPU is better, the diameter of the bubble hole is 142 u m, the bubble hole is uniform and fine, the apparent density is 0.7g/cm3, the tensile strength is 1.3 MPa, and the tensile strength decreases by 40%. The foaming process is as follows: the mass ratio of compound modified foaming agent I and 2#TPU is 1:32, the foaming temperature is 185 C, and the foaming time is 1min. Through the production of screw extruder for lofting test, it is found that the process is stable and repeatability is good. The diameter of the obtained sample is 140 micron m, the pore density is uniform and dense, the apparent density is 0.69 g/cm3, the tensile strength is 1.33 MPa, and the tensile strength is reduced by 36%.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ328;TB383.2

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