Study On The Influence Of Microphase Structure On The Damping Performance Of Polyurethane Materials

With the advancement of science and technology and the development of industrial society,the problems caused by vibration and noise from mechanical equipment have become increasingly serious.Vibration and noise not only pollute the environment and pose health risks to human beings but also significantly reduce the stability and accuracy of mechanical equipment,leading to fatigue damage.Damping materials have been widely used as effective measures for controlling vibration and noise.Polyurethane(PU)material,with its excellent stability,high strength,high modulus,wear resistance,chemical resistance,and thermal insulation properties,also exhibits outstanding vibration damping and noise reduction performance.Polyurethane materials are composed of alternating soft and hard segments,which have chemical incompatibility,resulting in a heterogeneous system.The size and degree of phase separation in this material can be designed,enabling the preparation of polyurethane materials with different microphase structures.Currently,there is limited research on the relationship between the phase structure and damping properties of polyurethane materials.This paper aims to prepare polyurethane materials with different phase structures and conduct in-depth research on the relationship between microphase structures and damping properties.It aims to provide a foundation for the study of the relationship between phase structure and damping properties of polyurethane materials.The specific research content is as follows:First,by selecting polyols with different regularities as the soft phase of the material,using the same isocyanate and chain extender as the hard phase,and blending polyols with different regularities,the influence of different regularities of the soft phase on the phase structure and damping properties will be investigated.The results show that when the hard phase composition is the same,a lower regularity of the soft phase leads to a higher degree of phase mixing and better damping properties.However,the mechanical properties of the material may be reduced.Second,by selecting polyols with the same structure but different molecular weights as the soft phase of different lengths,using the same isocyanate and chain extender to synthesize the same length of the hard phase,five polyurethane materials with different soft phase lengths will be prepared.By synthesizing different lengths of the hard phase using the same isocyanate and chain extender with different proportions and using polyols with the same molecular weight and structure as the soft phase,the influence of different soft and hard phase lengths on the phase structure will be studied.The results show that as the length of the soft phase increases,the damping performance initially increases and then decreases,while the mechanical properties gradually decrease.As the length of the hard phase increases,the damping performance decreases,and the mechanical properties improve.Finally,by selecting the same structure of isocyanate,chain extender,and polyol,different molecular weights of polyols and different synthesis ratios will be used to prepare polyurethanes with different distributions of soft and hard phases.Two systems will be prepared:one with side groups in the soft phase and one without side groups.The relationship between the phase structure and damping properties will be studied.The results show that as the concentration of the soft and hard phases becomes more focused,the damping performance of the system with side groups in the soft phase initially increases and then decreases,while the damping performance of the system without side groups in the soft phase gradually decreases.The mechanical properties of both systems initially increase and then decrease.