POE⁃g⁃MAH相容剂的制备及其在粘接树脂领域的应用研究

以马来酸酐（MAH）为接枝单体,乙烯?辛烯共聚物（POE）为基体树脂,无味过氧化二异丙苯（BIBP）为引发剂,通过双螺杆挤出机熔融挤出马来酸酐接枝乙烯?辛烯共聚物（POE?g?MAH）,以此作为粘接树脂的相容剂。研究了反应温度、螺杆转速及MAH用量对相容剂熔体流动速率、接枝率的影响,以及相容剂在粘接树脂中的应用。通过熔体流动速率仪、傅里叶红外光谱（FTIR）、万能试验机等对相容剂进行表征和分析;再将相容剂、基体树脂、以及相关助剂通过双螺杆挤出机挤出,得到的粘接树脂通过万能试验机检测其力学性能。结果表明,在引发剂BIBP的作用下,MAH可以顺利接枝到POE上,当MAH的添加量为1 %（质量分数,下同）、BIBP的添加量为0.1 %时,相容剂的接枝率可达0.7 %,熔体流动速率为0.691 g/10 min;在粘接树脂配方中加入20 %的相容剂后,粘接树脂的拉伸强度达到14.8 MPa,断裂伸长率达到1 031.1%,剥离强度达到178 N/25 mm。     

水辅助超临界二氧化碳制备TPU发泡颗粒

利用水和超临界二氧化碳作为共发泡剂,采用快速泄压法制备热塑性聚氨酯弹性体(TPU)发泡颗粒,分别考察了加水量、饱和温度和饱和时间对TPU发泡颗粒性能的影响。结果表明,当饱和温度为180℃、饱和时间为30 min时,随着加水量的增加,TPU发泡颗粒的边缘厚度明显降低,当加水量为4 mL时,发泡颗粒的边缘厚度比不添加水时下降了63.0%,同时发泡倍率提高了89.8%。当加水量为2 mL、饱和时间为30 min时,饱和温度的升高使得发泡倍率随之升高,饱和温度为190℃时的发泡倍率比饱和温度为150℃时提高了94.8%。当加水量为2 mL、饱和温度为180℃时,饱和时间超过1 h后,随着饱和时间的延长,发泡倍率和泡孔密度减小,边缘厚度和泡孔平均直径增大,并出现通孔结构。     

低光泽ASA材料研究

研究了不同流动性苯乙烯–丙烯腈塑料(SAN)、填料、弹性体和消光剂对丙烯腈–苯乙烯–丙烯酸酯塑料(ASA)材料光泽度及其它性能的影响。结果表明,降低SAN的流动性对ASA材料光泽度降低很小。添加填料可明显降低ASA材料的光泽度,但会降低ASA材料悬臂梁缺口冲击强度。添加片状滑石粉和云母对ASA材料光泽度的降低最明显。选用氢化苯乙烯–丁二烯–苯乙烯嵌段共聚物(SEBS)和马来酸酐接枝聚乙烯–辛烯共聚物(POEg-MAH)弹性体可大幅降低ASA材料的光泽度,而且添加SEBS弹性体还能提高材料的悬臂梁缺口冲击强度。添加交联苯乙烯–丙烯腈无规共聚物消光剂可显著降低ASA材料的光泽度,且对材料的悬臂梁缺口冲击强度影响较小。     

回收聚对苯二甲酸丁二醇酯的强韧化与耐热改性

以回收聚对苯二甲酸丁二醇酯（r-PBT）为原料,通过反应性熔融共混制备了r-PBT/环氧化弹性体（EVMG）共混物,并研究了EVMG添加量对r-PBT力学性能的影响规律。结果表明,当EVMG质量分数为20 %时,EVMG能够均匀分散于r-PBT中,粒径仅为500 nm,致使r-PBT的缺口冲击强度提高了14倍,断裂伸长率提高了7倍;进一步添加玻璃纤维 （GF）,使r-PBT/EVMG共混物的拉伸强度和耐热性显著提高;与纯r-PBT相比,添加质量分数为30 % GF后的r-PBT/EVMG/GF共混物在保持高韧性的同时,拉伸与弯曲强度提高70 %以上,且共混物的热变形温度达到176 ℃,为回收PBT材料的高值再利用提供了新方法。     

Polymerization of MMA at the surface of inorganic submicron particles

Inorganic submicron particles, such as TiO₂, were modified with titanate coupling agents. The structure and stability of some titanates, both in solution and at the particle surface, were investigated by various methods. The modified titanium dioxide was dispersed in a solution of sodium dodecylsulphate (SDS) in water. The surfactant adsorbs at the now hydrophobic particle surface, thus creating a micellelike structure with an inorganic particle in the centre. In this system an emulsion polymerization of methyl methacrylate was carried out. Product formed at the particle surface is either physically bound by entanglement or chemically bound by covalent bonding to the titanates. In this way a core-shell morphology is obtained with an inorganic core and a polymer shell. The effects of several reaction parameters on the kinetics of the polymerization were studied. The encapsulated TiO₂ particles may offer interesting prospects in those applications where good coupling between polymer matrix and inorganic particles is necessary, such as latex paints and polymer composite materials.     

CPE-g-PEG在CPE/P(AA-AM)吸水膨胀弹性体中的增容作用

选择自制的吸水树脂丙烯酸/丙烯酰胺共聚物(P(AA-AM))与氯化聚乙烯(CPE)为共混原料,以CPE-g-PEG两亲性接枝共聚物为增容剂,机械共混制备了增容型吸水膨胀弹性体(WSE).对共混物的亚微形态、吸水膨胀特性以及力学性能进行了研究.TEM结果表明简单共混时,CPE/P(AA-AM)共混物试样的相容性差.添加CPE-g-PEG后CPE与P(AA-AM)相间有一定程度的连接.接枝物的加入,改善了共混试样的重复使用情况,降低了其质量损失率,提高了WSE的稳定性,改善了试样的力学性能,接枝物加入量为6份时,拉伸强度最大.     

Thermomechanical reactive blending of silicone rubber and LLDPE: Effects of processing parameters

To prepare thermoplastic elastomers based on linear low density polyethylene (LLDPE) and silicone rubber (SR) the reactive blending of the two polymers was carried out at different processing conditions. Effects of mixing parameters such as temperature, shear rate, mixing time, and sequence of feeding the ingredients, upon the yield and rate of interfacial reaction, have been evaluated by following the variation of mixing torque and also by determination of the reacted fraction of silicone rubber. The yield and rate of the reaction increased by increasing the temperature of mixing, shear mixing rate, and the time of mixing. Changing the sequence of feeding the ingredients also changed the yield of the reaction. First feeding of polyethylene increased the yield of reaction. According to the obtained results, interfacial reaction between two phases is limited by chemical kinetics of the reaction and by rate of mass transfer during melt mixing. The order of interfacial reaction between these two polymers under thermomechanical conditions was found to be about 1.1. Rheological studies on the blends performed by using rheomechanical spectroscopy showed a distinct rheological behavior with a non‐Newtonian characteristic and higher dynamic viscosity at low frequencies for the blends prepared at high temperature and shear rate. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 155–161, 2005     

称重传感器弹性元件结构参数对非线性误差的影响

文中对大吨位高精度称重传感器弹性元件进行了有限元分析．分析和计算结果表明，设计弹性元件时，主要考虑弹性元件贴片区的长度和直径及过渡圆弧半径．弹性元件上下端部结构尺寸只要满足工艺要求即可．这为弹性元件的优化设计和结构参数的确定提供了理论依据。     

纳米CaCO3对聚烯烃聚氨酯弹性体性能影响

以端羟基聚丁二烯（HTPB），甲苯二异氰酸酯（TDI）为原料，帛备了聚烯烃聚氨酯预聚体，以E－300作为固化交联剂，研究了癸二酸二异丬酯（DOS），纳米CaCO3含量以及混合时间对聚烯烃聚氨酯弹性体性能的影响。测试了料浆的粘度变化以及弹性体的力学性能，结果表明，添加适量的纳米CaCO3对聚烯烃聚氨酯弹性体具有补强作用，添加适量的癸二酸二异丬酯和选择合适的混合时间可以提高弹性体的性能，当纳米CaCO3为15g，癸二酸二异辛酯为10g，混合时间为20min左右时，弹性体材料具有最佳性能。