GNF/PZT/polymer Piezoelectric Damping Composites

Polymer damping materials have an extremely important application in the field of vibration and noise reduction.However,the ideal damping performance of polymers can only be obtained in a narrow temperature range near glass transition temperature about several ten degrees.The piezoelectric damping composite was invented by introducing the energy dissipation way of force-electricity-heat to qualify higher demands,and has owned very promising opportunity both in active and passive vibration control for many applications.The main work and conclusions of this paper are as follows:1)Firstly,polyurethanes with different ratio of hard and soft segments,graphene sheets and 3-D graphene?GNF?were prepared.It was found that the polyurethane had the best damping performance when the molar ratio of PTEMG:MDI:glycerol was 7:10:2 and the sizes of graphene sheets prepared were between 10?m²00?m.The graphene distribution of GNF constantly changed with the graphene content while graphene happened to almost completely coat the polyurethane skeleton when the graphene content was 25.4 wt%.2)The damping properties of PU/PZT composites and PU/PZT/GNF piezoelectric damping composites were investigated.It was found that PU/PZT composites had the best damping performance when 2g PZT was added per 100g polyurethane.Piezoelectric damping composites were fabricated by compositing GNF with PU and PZT.The results showed that the composite owned the best damping properties at the conductive threshold about 0.7wt%graphene content,and the Tg was-53.76?,the maximum loss factor was 0.77.The loss factor was enhanced by 0.22?close to 41%?and the damping temperature range was broadern 13.2°C?close to84%?compared to the PU matrix.At the same time,polyurethane/graphene composites were prepared for comparison.It was found that the conductive threshold was greater than 0.9wt%and the maximum tensile strength was obtained when the graphene content was 0.6wt%,indicating that the use of three-dimensional structures reduced the conductivity percolation threshold and decreased the effect on the tensile strength of the matrix itself.3)The polyurethane/acrylate IPNs copolymer were prepared.The results reveled that the damping property of IPN copolymer was best when the mass ratio of PU:BMA:MMA was 1:2:1,in which the Tg was 64.4?,the tan?_max was 1.16,and the damping temperature range was 47.0⁹8.3?.Compositing IPN with PZT,the results showed that the best damping property was obtained when 20g PZT was added per 100g IPN copolymer.The Tg of the composite was 76.2?,the tan?_max was 1.19 and the damping temperature range was 57.4¹14.2??56.5??.4)A three-phase piezoelectric damping composite was prepared that used the IPN as matrix.It reached the comductive threshold when the 25.4wt%graphene content GNF was used to be the conductive phase,and the proportion of graphene in the composite material was about 0.55wt%.For this composite,the Tg was 59.3°C,the tan?_max was 0.96 and the damping temperature range was 33.6°C¹00.7°C?67.1°C?.Compared with the IPN matrix,the damping temperature range was broaden 16??near 28%?.What's more,its damping temperature was close to room temperature,and had a higer tan??0.24?than IPN matrix?tan?was 0.13?and IPN/PZT composite?tan?was 0.16?at room temperature?25°C?.