聚氨酯IPN阻尼材料研究进展

介绍了互穿聚合物网络(IPN)材料的阻尼机理及其表征方法,并重点综述了聚氨酯(PU)IPN材料的研究进展。     

聚氨酯IPN阻尼性能研究进展

介绍了互穿聚合物网络(IPN)材料的阻尼机理。综述了聚氨酯(PU)IPN阻尼材料的研究进展及新的可能的发展方向。     

互穿网络对硅橡胶包覆层的补强研究

采用分步IPN、同步IPN等方法制备了硅橡胶互穿网络产物,研究发现聚氨酯同步IPN较难有效提高硅橡胶包覆层的力学性能,采用甲基丙烯酸乙脂分步IPN可以大幅度提高硅橡胶包覆层的力学性能,硅橡胶拉伸强度最高可达6.62MPa,但形成互穿网络以后,导致硅橡胶包覆层的热稳定性能降低,400℃时,硅橡胶质量残留量为82.41%,而硅橡胶与甲基丙烯酸乙酯形成的IPN的质量残留量为30.15%。     

三元互穿聚合物网络材料阻尼性能研究

采用同步法制备了聚氨酯 /环氧树脂 /丙烯酸酯三元互穿聚合物网络 (IPN) ,采用动态力学分析法研究了IPN的阻尼性能 ,以及影响材料阻尼性能的因素。研究结果表明 :三元互穿聚合物网络力学损耗因子≥ 0 .6的温度范围在 2 8～ 75℃ ;≥ 1 .4 ,表现出优异的高温阻尼性能     

蒙脱土改性PU/EP IPN的研究

本文通过端异氰酸酯基聚氨酯预聚体与环氧树脂E-51形成了互穿网络,并通过热重分析仪(TGA)研究了完全固化后的互穿网络的热分解行为;透射电镜研究了IPN的相分离行为及用拉伸强度,断裂伸长率对其进行了力学性能的表征.结果表明,经过环氧树脂改性的聚氨酯的耐热性能比纯聚氨酯得到了提高,且力学性能也有所改善.并选取性能较好的PU/EP IPN,用纳米级有机蒙脱土对其进行了改性.研究发现,经有机纳米蒙脱土改性的PU/EP IPN的力学性能及耐热性有了进一步的提高.     

聚氨酯IPN的研究——制备方法与性能的关系

介绍了聚氨酯 IPN合成技术的主要特征 ,PU预聚体分子量大小、NCO/ OH的比值 ,互穿网络的方式及反应温度、速率对性能的影响     

聚氨酯/环氧树脂互穿网络半硬泡沫的热稳定性

制备了聚氨酯/环氧树脂互穿网络半硬泡沫,通过热重分析(TGA)研究了其热分解,计算了各分解阶段的热分解反应动力学参数。结果表明,氮气中,互穿聚合物网络(IPN)泡沫根据环氧树脂含量不同其分解过程有2~3个失重阶段,随着环氧含量增加,第一阶段的失重率减小,第二阶段的失重率增大。IPN泡沫在第一、二两阶段总的热失重率低于纯聚氨酯泡沫及纯环氧树脂。环氧树脂含量为30%(质量分数,下同)时泡沫的热稳定性最好。预测IPN半硬泡沫在100℃氮气中失重5%时的热老化寿命可达2.4E7年,表明IPN泡沫具有很好的热稳定性。     

聚碳酸亚丙酯型聚氨酯/聚甲基丙烯酸甲酯互穿网络聚合物的研究

用同步法合成了聚碳酸亚丙酯聚氨酯/聚甲基丙烯酸甲酯互穿网络聚合物(PPCPU/PMMA IPN),调节IPN中两组分配比制备出多种高聚物合金.用DSC、TEM对IPN的研究结果表明,PPCPU/PMMA IPN的两组分是互不相容的,同时对各种组成比的IPN材料进行力学性能测试,并用SEM对断面进行了观察解释.实验结果发现,IPN的密度大于相应体系体积加和值.     

两类室温固化的蓖麻油聚氨酯互穿网络材料

研究了五种取代乙烯分别与蓖麻油聚氨酯生成的互穿网络聚合物(IPN)的力学性能与其组成的关系,指出聚氨酯含量在65％左右拉伸强度最大,最大强度与取代乙烯均聚物的玻璃化转变温度有关。NCO/OH比愈大,IPN的交联密度愈大,伸长率愈小,拉仲强度愈大。由丙烯酸丁酯生成的IPN具有弹性体性能。还研究了蓖麻油聚氨酯与不饱和聚酯及取代乙烯生成的IPN,指出丙烯腈作为取代乙烯所得的IPN性能最好,不饱和聚酯与丙烯腈的重量比不宜超过1/1。后一IPN的扫描电镜照片表明具有微观相分离的形态结构。     

聚氨酯/环氧树脂互穿网络硬泡的静态压缩行为

采用同步法合成了聚氨酯/环氧树脂互穿聚合物网络硬泡。为了研究聚氨酯/环氧树脂互穿网络聚合物(PU/ERIPN)硬泡对压缩载荷的响应及变形机理,对IPN硬泡进行了应变率在1.67×10-4s-1~1.67×10-2s-1范围内的静态压缩试验。研究表明,PU/ER IPN硬泡的压缩行为表现出明显的各向异性和应变率效应。平行发泡方向上的应力-应变曲线表现出三个变形阶段:即弹性阶段,"平台"阶段和"硬化"密实阶段,其平台阶段的显著特征是应变软化和局部变形。讨论了IPN硬泡的压缩力学本构关系。     

基于溶解度参数分析方法的IPN密封材料研究

目的基于耐溶剂性原则选择硝酸异丙酯的密封材料。方法通过溶解度参数的计算验证丁腈橡胶(NBR)与IPN会产生溶胀效应。根据聚合物的耐溶剂性原则,选择三元乙丙橡胶(EPDM)和聚四氟乙烯(PTFE)代替丁腈橡胶,而后比较各材料与IPN的溶解度参数差值。结果 IPN在NBR的可溶球体范围内,两者的三维溶解度参数十分接近;IPN,EPDM与PTFE的一维溶解度参数分别为8.6,7.7,5.14,EPDM与IPN的溶解度参数较为接近;PTFE与IPN的溶解度参数相差较大。结论 EPDM与PTFE均比NBR更适合密封IPN,其中EPDM最适合密封IPN。     

PF／PnBA IPN的合成及相容性研究

本文采用乳液和溶液聚合法合成PF/PnBA IPN,并对产物进行了动态力学性能、热重分析及微观形态研究。结果表明,IPN可使组分相容性得到提高热性能得以改善,乳液聚合与溶液聚合法合成IPN产物的微观形态有所不同。     

Preparation,damping and thermal properties of potassium titanate whiskers filled castor oil-based polyurethane/epoxy interpenetrating polymer network composites

A series of potassium titanate whiskers (PTW) filled castor oil-based polyurethane (PU)/epoxy resin (EP) interpenetrating polymer network (IPN) composites were prepared. The damping properties, thermal stability as well as tensile strength of the IPN composites were studied systematically in terms of composition. Results revealed that the addition of PTW can significantly improve the damping properties of pure PU/EP IPN and can improve the thermal decomposition temperature. Tensile tests showed that the tensile strength of the IPN composites was improved after the incorporation of PTW. It is expected that the PTW filled IPN composites may be used as structural damping materials.     

Damping analysis of polyurethane/epoxy graft interpenetrating polymer network composites filled with short carbon fiber and micro hollow glass bead

A series of short carbon fiber (CF) and micro hollow glass bead (HGB) filled polyurethane (PU)/epoxy resin (EP) graft interpenetrating polymer network (IPN) composites were prepared. The damping properties, thermal stability properties as well as tensile and impact strength of IPN composites were studied systematically. Results revealed that the addition of short carbon fiber and micro HGB can significantly improve the damping properties of pure PU/EP IPN and can improve the thermal decomposition temperature. Mechanical tests showed that the tensile strength of the IPN composites could be improved after the incorporation of short carbon fiber and micro HGB, while the impact resistance of the composites was impaired after the addition of micro HGB. It is expected that the carbon fiber and micro HGB filled IPN composites may be used as structural damping materials.     

聚氨酯／环氧树脂互穿网络聚合物相行为与断裂拉伸强度

制备了一系列聚氨酯／环氧树脂互穿网络聚合物ＰＵ／ＥＰＩＰＮ，由ＤＳＣ，ＴＭＴ和动态粘弹仪研究表明，ＩＰＮ在高温区存在的单一玻璃化转变温度Ｔｇ，ＩＰＮ的的相行为与其断裂伸强度的相关，并确认接枝共聚物的存在增强了ＩＰＮ的互穿效应。     

激波驱动下硝酸异丙酯的分散变化规律研究

研究液滴的分散过程对于阻止火灾蔓延、提高内燃机效率、改进云雾爆轰武器和提高云雾爆轰控制技术有着重要的作用。通过高速摄影技术以及压力测量系统,着重研究液态燃料硝酸异丙酯（IPN）的分散过程,分析液膜厚度和激波强度对IPN液膜分散的影响。IPN液膜初始阶段以水平方向的分散为主;随后,以竖直方向的分散为主。水平方向,液膜抛洒先进入减速阶段,随着液膜厚度H的增加,液膜分散效果变差,分散需要的时间更长,其分散表征与石油醚相似。IPN液膜分散所需能量要高于石油醚。激波强度超过某个值之后,超压比ε随液膜厚度H呈线性变化,可以为液膜分散提供足够的能量。当H＜12 mm时,IPN液膜的分散变化过程主要受激波强度影响;当H＞12 mm时,IPN液膜的分散变化过程主要受液膜厚度影响。     

温敏性丝胶蛋白/聚(N-异丙基丙烯酰胺)互穿网络水凝胶的结构与形态

采用同步-互穿网络方法制备丝胶蛋白(SS)/聚(N-异丙基丙烯酰胺)(PNIPAAm)互穿网络(IPN)水凝胶。用傅立叶红外光谱仪(FT-IR)对其组成结构进行表征,表明形成了互穿网络结构水凝胶。通过透射电镜(TEM)和差示量热扫描(DSC)研究两相微结构,结果显示,尽管两相间存在微观相分离,但两者之间仍然具有一定的相容性。扫描电镜(SEM)观察到该水凝胶具有相互贯通的多孔结构。热失重(TG)研究发现,IPN提高了SS的热稳定性。     

光固化型聚氨酯/环氧树脂IPN的制备与表征

采用ＩＰＮ技术,制备了一系列光固化型的聚氨酯与环氧树脂的ＩＰＮ树脂,经力学性能测试表明当ＰＵ／ＥＰ＝７０／３０时,ＩＰＮ的断裂伸长率达１６０％。,拉伸强度比纯ＰＵ提高２１０％,显示出良好的正协同效应。利用红外光谱,光谱微镜,应力－应变,硬度等测试手段对ＰＵ／ＥＰ的互穿网络的结构：两组分的相容性,微相分离的形态结构进行了表征。并且探讨了ＩＰＮ的结构与力学性能之间的关系及影响因素,认为：ＰＵ／ＥＰ的Ｉ     

Aliphatic amine cured PDMS-epoxy interpenetrating network system for high performance engineering applications—Development and characterization

A siliconized epoxy interpenetrating network (IPN) was synthesized from commercially available DGEBA epoxy resin GY250 (Ciba-Geigy, epoxy equivalent = 182–192, viscosity = 9000–12000 cP) and hydroxyl terminated polydimethylsiloxane (PDMS). PDMS and GY250 were thoroughly mixed at 30°C to get the prepolymer. Stoichiometric amounts of PDMS-epoxy prepolymer, γ-aminopropyltriethoxysilane, aliphatic amine curing agent (HY951), and dibutyltindilaurate catalyst, were thoroughly mixed and cast in a mould after evacuating the entrapped air. The cured material was then taken out and post cured at 70°C for 10 h. IPN was characterized by FTIR spectroscopy, SEM, DSC, TGA and viscosity measurements. Incorporation of PDMS in the epoxy matrix increased the viscosity and lowered the exotherm and pot-life. PDMS in IPN increasedT _g, heat-distortion temperature and reduced the percentage weight loss with increase in temperature. Incorporation of PDMS drastically reduced the tensile and flexural strengths and hardness. By reducing the tensile and flexural modulus, the siloxane moiety effectively reduced the internal stress of IPN thereby improving its impact strength and percentage elongation. PDMS increased the electric potential gradient of IPN to withstand without breakdown. An increase in the tracking index and arc resistance of IPN were observed, because of the presence of Si-O-Si, which minimized the possibility of forming carbonized path. Volume and surface resistivities of IPN also increased with the incorporation of PDMS. The siliconized epoxy IPN, with better impact and thermal resistance, may be used in automobile and aerospace applications to withstand high temperature, and mechanical stress. The PDMS-epoxy IPN may be used for encapsulation, high temperature and high voltage application due to their low shrinkage and lesser internal stress. With the improved electrical characteristics, IPN may be used for high performance electrical insulation, insulator housings, and encapsulation to withstand high voltage, moisture, oxidation, chemical attack, biological attack, outdoor weathering, contamination, electrical, mechanical and thermal stress.