Based on the novel USW method, the welds of Polylactide (PLA) - Polyformaldehyde (POM) and PLA - polymethyl methacrylate (PMMA) have been carried out. The interdiffusion processes of polymer chains have also been investigated according to the reptation theory and the hauling theory. The welding strengths are carried out by the universal tester and the rupture interfaces are observed using the scanning electron microscope. The best welding strength is 52MPa (90% compared with PLA of the PLA-POM system), which can reach the tensile strength of IPS. The molecules of POM are much easier to inter-diffuse than those of PLA and PMMA.

Mechanical noise caused by power equipment vibration is the main source of underwater radiated noise of the ship, and vibration isolation and noise reduction of ship equipment has been widely concerned. Therefore,a vibration isolation system designed for four sets of auxiliary engine of ship cabin was investigated in the paper, aimed to further reveal the influence of various parameters including floating raft shell thickness, excitation source, and different ship hull and installation platform thickness on the vibration level difference of system. The results obtained from numerical analysis using MSC software and experiment indicate that one-dimensional spring element simplified can properly simulate the actual rubber vibration isolator on low frequency bands, and increasing thickness of flat, hull and platform can improve the effect of vibration isolation obviously.

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Recently in electronic and automobile industry, polymer materials were selected to replace metals in many products because of miniaturization and weight reduction. So the weld between polymers and metals became very important. Currently, the ways were limited to adhesive joint or the mechanical weld which both had obvious defects. In this paper, the direct-welding methods were studied and the welds based on compress-molding were viable and useful. The welding strength enhanced because the reaction between polymers and modified metals were confirmed.

New types of conducting composites using andalusite as an inorganic substrate and polyaniline as the conducting phase were prepared. The composites exhibited conductivities in the 0.14-2.08 S/cm range, depending on the amount of polyaniline. The thermal stability of andalusite/polyaniline composites were studied by thermogravimetric analysis. The resulting composites were also characterized by using FTIR spectroscopy and scanning electron microscopy.