环氧/聚氨酯梯度互穿网络聚合物冲击性能研究

研究了采用梯度IPNs方法提高环氧树脂的冲击性能,设计了新型梯度组分分布数学模型描述梯度组分的分布,采用梯度因子和梯度层数控制梯度IPNs的结构变化。并采用逐层浇铸的方法制备了不同种类的环氧/聚氨酯(EP/PU)梯度互穿网络聚合物(IPNs)材料,同时对其冲击性能进行了研究。研究结果表明,梯度结构的变化对其冲击性能有所影响,梯度层数越多,梯度因子越大,梯度IPNs的冲击强度越大。在质量比相同的情况下,梯度IPNs的冲击性能要高于普通IPNs和环氧。     

聚氨酯/乙烯基树脂互穿聚合物网络的研究进展

综述了聚氨酯/乙烯基树脂互穿聚合物网络（PU/VER IPNs）中两组分的聚合机理;重点讨论了分步IPNs、同步IPNs和胶乳IPNs的制备方法及其研究进展;介绍了PU/VER IPNs合成动力学的研究方法,包括化学滴定法、差示扫描量热法和傅立叶变换红外光谱法。     

EP/PUR梯度互穿网络聚合物的制备及其拉伸性能研究

提出一种新的方法对梯度互穿网络聚合物(IPNs)中梯度组分的分布进行设计,并采用逐层浇注的方法制备了不同层数的环氧树脂/聚氨酯(EP/PUR)IPNs,对其拉伸性能进行了研究。研究结果表明,EP/PUR梯度IPNs的拉伸性能受梯度层数的影响,梯度层数越多,拉伸弹性模量越小,拉伸强度高,但当梯度层数超过7层后,拉伸强度有所降低;EP/PUR梯度IPNs的拉伸性能优于EP和EP/PUR普通IPNs。     

环氧树脂/丙烯酸酯互穿网络聚合物及其流变性能研究

采用甲基六氢邻苯二甲酸酐( MeHHPA)作为新型脂环族环氧树脂(CER)的固化剂,选用过氧化二异丙苯为三羟甲基丙烷三甲基丙烯酸酯( TMPTMA)的引发剂,制备了一种新的CER/TMPTMA互穿网络聚合物( IPNs).通过扫描电子显微镜表征并证实了IPNs的形成过程.研究发现,由于TMPTMA的自由基聚合反应先于C...     

接枝聚氨酯/环氧树脂/丙烯酸酯互穿网络聚合物的制备与性能

采用分步法制备了接枝聚氨酯(PU)/环氧树脂(EP)/丙烯酸酯(PA)互穿网络聚合物(IPNs),研究了不同接枝程度对聚合物热性能、动态性能以及黏接性能的影响。结果表明,PA与PU、EP互穿网络形成了接枝结构;热重分析(TGA)结果证实接枝IPNs的热稳定性明显优于非接枝IPNs;动态力学分析(DMA)显示,接枝能够使材料的相容性改善;黏接强度测试显示,当丙烯酸羟乙酯(HEA)质量分数为3%时,材料的T型剥离强度达到极大值4.6kN/m。     

蓖麻油型聚氨酯/PS同步IPNs的协同效应研究

采用同步互穿网络技术,制备了一系列蓖麻油型聚氨酯/聚苯乙烯（COPU/PS）互穿网络聚合物（IPNs）,研究了它们的力学性能和溶胀性能.结果表明,当PS/COPU、BPO（过氧化二苯甲酰）/St（苯乙烯）质量分数分别为30%和1.5%时,三羟甲基丙烷（TMP）和蓖麻油羟基的摩尔比、NCO与OH的摩尔比分别为0.2和1.3时,互穿网络材料的相容性好,协同效应明显,此时力学性能最佳.当COPU/PS的IPNs材料中PS质量分数为20%～40%时,由于两相的互穿作用,使二甲苯对IPNs材料的溶胀趋缓;并且随着交联剂TMP的增加,平衡溶胀增重率增幅变小,到TMP和蓖麻油的羟基摩尔比值大于0.2后,平衡溶胀增重率基本不变.     

DCPDE/PUR互穿聚合物网络的制备与表征

以聚氨酯(PUR)预聚体、二氧化双环戊二烯环氧树脂(DCPDE)为基体,分别以顺丁烯二酸酐(MA)和甘油为固化剂和促进剂,制备了新型DCPDE/PUR互穿聚合物网络(IPNs)复合材料。采用红外光谱法、热重分析法和差示扫描量热法等手段对该IPNs材料的化学结构、热性能和力学性能进行了表征。结果表明,PUR加入DCPDE固化体系,形成了IPNs结构,提高了复合材料的韧性,降低了刚性。PUR质量分数为30%时,复合材料的拉伸强度相对稳定,冲击强度提高了16.4 kJ/m2,断裂伸长率提高了12.4%,弯曲强度略微降低;复合材料的热分解温度在360℃以上,热稳定性良好。     

四针状氧化锌晶须/互穿网络聚合物复合材料研究

以CYD-127环氧树脂(EP)、聚氨酯(PU)、柔性固化剂聚醚胺D400和四针状氧化锌晶须(T-ZnOw)为原料制备了PU-EP IPNs互穿网络聚合物及其复合材料。通过红外光谱、热机械分析、热分析、电镜分析及力学性能测试研究了不同配方PU-EP IPNs的阻尼性能,以及填料T-ZnOw对PU-EP IPNs/T-ZnOw复合材料阻尼性能、拉伸性能和热稳定性的影响。研究表明:PU质量分数30%的PU-EP IPNs的有效阻尼温域(△T)最宽,达到113.3℃,PU质量分数10%的PU-EP IPNs的阻尼峰值最大。当改性T-ZnOw用量为环氧树脂质量的1%时,复合材料阻尼性能最好。T-ZnOw质量分数为2%时,复合材料拉伸强度最大。随T-ZnOw用量增加,复合材料热稳定性提高。     

外电场对CER/TMPTMA IPNs形成过程的在线监测

利用自制装置研究了脂环族环氧树脂(CER)/三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)互穿网络聚合物(IPNs)的固化过程.通过在线测试CER/TMPTMA体系固化过程中的交流电阻和电容,发现电阻和电容的变化反映出CER/TMPTMA体系的固化过程是一个分步IPNs的形成过程,而且电阻和电容变化趋势与体系的粘度、离子浓度以及偶极子的数量息息相关.利用自制电极和装置可以远距离在线监测热固性树脂的固化过程,在外磁场干扰下,利用CER/TMPTMA固化体系的电阻波动可以表征体系的固化反应情况.     

增韧改性环氧树脂互穿网络聚合物的合成与表征

合成了端异氰酸酯/环氧丙烯酸树脂互穿网络聚合物,在环氧树脂交联网络中引入柔性链段,达到增韧的目的。通过改变端异氰酸酯和环氧丙烯酸树脂的组分比,合成不同组成的互穿网络聚合物(IPNs)。借助红外光谱和扫描电镜等分析方法,研究了IPNs的分子混合形态结构。同时采用差热分析法(DSC)测试了聚合物的玻璃化转变温度,结果表明:端异氰酸酯预聚体含量越高,聚合物的玻璃化转变温度越低。对成膜物的力学性能研究表明,INPs的拉伸强度在端异氰酸酯/环氧丙烯酸树脂比例为30:70时,拉伸强度为55.24 MPa,是纯环氧树脂的2.5倍。     

互穿聚合物网络技术在聚氨酯中的应用

综述了互穿聚合物网络(IPN)技术在聚氨酯材料中的应用研究进展。简述了聚氨酯IPN的制备,具体叙述环氧树脂、聚丙烯酸酯、聚硅氧烷、乙烯基酯树脂等聚合物与聚氨酯互穿网络改性的效果,并在此基础上展望了聚氨酯互穿网络聚合物的发展趋势。     

Mechanical properties of blocked polyurethane/epoxy interpenetrating polymer networks

The mechanical properties of blocked polyurethane(PU)/epoxy interpenetrating polymer networks (IPNs) were studied by means of their static and damping properties. The studies of static mechanical properties of IPNs are based on tensile properties, flexural properties, hardness, and impact method. Results show that the tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs decreased with increase in blocked PU content. The impact strength of IPNs increased with increase in blocked PU content. It shows that the tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (CaCO₃) content to a maximum value at 5, 10, 20, and 25 phr, respectively, and then decreased. The higher the filler content, the greater the hardness of IPNs and the lower the notched Izod impact strength of IPNs. The glass transition temperatures (T_g) of IPNs were shifted inwardly compared with those of blocked PU and epoxy, which indicated that the blocked PU/epoxy IPNs showed excellent compatibility. Meanwhile, the T_g was shifted to a higher temperature with increasing filler (CaCO₃) content. The dynamic storage modulus (E′) of IPNs increased with increase in epoxy and filler content. The higher the blocked PU content, the greater the swelling ratio of IPNs and the lower the density of IPNs. The higher the filler (CaCO₃) content, the greater the density of IPNs, and the lower the swelling ratio of IPNs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1826–1832, 2006     

Synthesis and mechanical properties of leather–epoxy interpenetrating polymer networks

Leather–epoxy interpenetrating polymer networks (IPNs) were synthesized; these IPNs have an approximate epoxy concentration of 25 wt %. The flexural and tensile moduli of the IPNs prepared are equivalent to those of the epoxy resin. The Izod impact energy and fracture toughness measured for the IPNs, however, exceed those attained by the epoxy resin alone by at least a factor of 4. The glass transition of leather–epoxy IPNs occurs over a wide temperature range, thus indicating that the IPN is an intimate admixture of the epoxy resin throughout the collagen matrix of the hide. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1224–1232, 2000     

Uralkyd and poly (butyl methacrylate) interpenetrating polymer networks

ABSTRACT:: Hydroxyl terminated alkyds synthesized from castor oil, glycerol, and different dibasic acids were used to develop uralkyds and their interpenetrating polymer networks (IPNs) with polybutyl methacrylate (PBMA). Glass transition temperature measurements gave the evidence of interpenetration. The IPNs were characterized for their physicomechanical properties and their phase morphology was studied by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). As the concentration of the uralkyd in IPNs increases, a gradual increase in elongation, density, and swelling with a consequent decrease in the hardness were observed for all IPNs. Swelling is relatively more prominent in methyl ethyl ketone (MEK) and toluene than in water. From SEM it was observed that IPNs of PBMA‐uralkyd containing phthalic anhydride (UA‐P) as an acid part showed greater compatibility than those containing dimethyl terephthalate (UA‐D). From thermogravimetric analysis (TGA) no significant change was observed in the degradation behavior of the IPNs. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 825–832, 2000     

Effect of physical ageing on the viscoelasticity of interpenetrating polymer networks

The effect of physical ageing on viscoelastic properties was studied for semi‐IPNs based on crosslinked polyurethane and poly(butyl methacrylate) taken in the ratio 75/25 by mass. The viscoelastic properties of IPNs were studied after physical ageing and after heat treatment at 60 °C. Significant changes in viscoelastic behaviour after ageing were observed. It was found that heterogeneous systems such as IPNs have their own specific features of physical ageing which are related to the existence of two glass transition to temperatures. Relaxation processes to establish the equilibrium state may need a long period of time. © 2000 Society of Chemical Industry     

Thermal properties of poly(vinyl alcohol)/poly(diallyldi‐methylammonium chloride) interpenetrating polymer networks

Interpenetrating polymer networks (IPNs) constructed with poly(vinyl alcohol) (PVA) and poly(diallyldimethyl ammonium chloride) (PDADMAC) using a sequential IPN method were prepared. The thermal characterization of the IPNs was investigated by differential scanning calorimetry (DSC), dielectric analysis (DEA), and thermogravimtric analysis (TGA). Decreases in the melting temperature of PVA segments in IPNs were observed with increasing PDADMAC content using DSC. DEA was employed to ascertain glass transition temperature of IPNs. The thermal decomposition of IPNs was investigated using TGA, and thermal decomposition of IPNs could be decelerated by changing PVA content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1346–1349, 2003     

Radiation synthesis and environmental responsiveness of semi‐interpenetrating polymer networks composed of poly(dimethyl–aminoethyl methacrylate) and poly(ethylene oxide)

Semi‐interpenetrating polymer networks (semi‐IPNs) composed of poly(dimethyl–aminoethyl methacrylate) (PDMAEMA) and poly(ethylene oxide) (PEO) were synthesized by γ‐radiation; three semi‐IPNs with 80 : 20, 90 : 10, and 95 : 5 weight ratios of DMAEMA/PEO were obtained by use of this technique. The gel–dose curves showed that the hydrogels were characterized by a structure typical of semi‐IPNs and the results of elemental analysis supported this point. The temperature‐induced phase transition of semi‐IPNs with the composition of 95 : 5 was still retained, with the lower critical solution temperature of PDMAEMA shifting from 40 to 27°C. The temperature sensitivity of the other two semi‐IPNs gradually disappeared. The pH sensitivity of three semi‐IPNs was still retained but the pH shifted slightly to lower values with increasing PEO content in the semi‐IPNs. The effect of PEO content in semi‐IPNs on their environmental responsiveness was discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2995–3001, 2004