Preparation And Properties Research Of Interpenetrating Polymer Network Damping Property Material

Damping materials which are used in controlling libratation and yawp ofmechanical equipment have extensive market prospect. The research anddevelopment of damping materials, which have high capability and low costs, hasprofound theoretical and practical significance, so the viscoelasticity dampingmaterials which have these properties have become the hotspot.Based on relative relation of structure and property and the method ofmolecular devise, a new kind of polyurethane/vinyl ester resin(PU/VER) IPNdamping materials was prepared and modified VER and PU/modified VER IPNdamping materials were prepared by the method of sealing hydroxyl groups ofthe AAEP resin in VER in order to prepare the material which can reducevibration and noise with wide temperature range and excellent dampingperformance in the range of room temperature.A new kind of PU/VER IPN damping materials was prepared at roomtemperature by simultaneous interpenetrating process of PU synthesized in ourlaboratory and VER resin which has acrylic esters as its comonomers instead ofgeneral styrene(St). Optimizational technological parameters were determined bytracking and semi-quantitative analysis of IR. Dynamic mechanical properties ofIPN materials were studies by DMA and major factors affecting dampingproperties were analysed. The microstructure and compatibility of IPN werestudied by TEM. Preliminary measurement of mechanical properties were done.The results show that the compatibility and dampilng properties of generalPU/VER(St) IPN are improved by introducing acrylic esters as VER's comonomers. The process of simultaneous interpenetrating is realized byadjusting the amounts of PU's catalyst and VER's initiators. Thermodynamicfactor(the type of components), kinetic factor(the relative polymerization rates),component ratio have great effects on their damping properties and differentmicrostructure because of different polymerization processes results in differentdamping properties. PU/VER(BMA) IPN with long butyl ester groups shows bestdamping properties. 80/20, 70/30 and 60/40 PU/VER(BMA) IPNs have domainsof nanometer scale and tanδvalues of higher than 0.3 are in the temperaturerange of 78℃, 84℃and 99℃which meet the requirement of excellent dampingmaterials. IPN materials show the regulation from elastic deformation to brittledeformation with the increase of VER proportion.Different methods were carried out to seal hydroxyl groups of VER. The IRwas adopted to study the influence of the reagents used to seal the hydroxylgroups, the reaction temperature, and the ratio of two materials on the removaleffects of hydroxyl groups of AAEP in the VER and optimizational technologicalparameters were determined. PU/modified VER IPN damping materials wereprepared at room temperature by simultaneous interpenetrating process of PUsynthesized in our laboratory and modified VER. The influence of chemicalbonds between the two networks on the damping properties, microstructure andcompatibility was studied by DMA and TEM. The mechanical properties ofPU/VER IPN and PU/modified VER IPN were compared. The results show thatbecause chemical bonds don't exist between the networks, the modified IPNmaterials show bigger phase ranges. Tang values of 60/40 PU/modifiedVER(BMA) IPN higher than 0.3 are in the temperature range -49℃～＞80℃andthe highest tanδvalue is 0.90 which show that the effective damping temperaturerange is broadened and the damping properties are improved. Compared tounmodified IPN materials, the tensile strength of PU/modified VER IPNdecreases, while its break elongation increases.