Research On Preparation And Damping Property Of EPDM Foamed Material

The special stucture endows foamed material with excellent acoustic insulation, damping and thermal insulation properties. The high saturation of molecular chains endows EPDM (Ethyl ene-Propylene-Diene Monomer) with conspicuous thermal stability, cold tolerance and physical mechanical property. A foamed material with the matrix of EPDM could have huge application prospects in the fields of packaging, construction, transportation and so on.A curometer was adopted to test the EPDM compound's curing characteristics, and TA (thermogravimetric analysis) was used to explain the foaming agent's decomposition temperature. Besides that, SEM (scanning electron microscope) was adopted to observe the foamed material's cellular structure. Influence of formula factors such as curing agent, foaming agent, filler and process factors such as temperature and time on EPDM foamed material's macroscopic mechanical property and microscopic cellular structure were discussed. The results showed that, taking EPDM as the foam matrix, when combining vulcanization accelerator M with vulcanization accelerator TT, with the dosage of AC 12phr, carbon black N550 40phr, EPDM foamed material could obtain the optimum mechanical property and the best cellular structure under the condition of 185℃,15 minutes.The crosslinking degree was characterized by a HAAKE rheometer, and the curing characteristic was displayed by a curometer. Combining the results with the apparent density and the expansion ratio, the feasibility of precure process on EPDM foamed material's preparation was proved. With the dosage of sulfur 0.05phr and the gel content 10%, EPDM molecular chain's relaxation time was prolonged. At the same time, the utilization ratio of foaming agent was improved, and the processing platform was widened.Via testing the compression stress-strain curve, effects of foaming agent loading and filling agent loading on EPDM foamed material's compressive behavior was discussed and its energy-absorption features under different stress and strain levels were analysed. Energy absorption efficiency E and ideal parameter I were defined to evaluate EPDM foamed material's energy absorption performance at constant strain. EPDM foamed material could gain the best energy absorption property and the highest energy absorption efficiency with the dosage of AC 12phr.Depending on DMA (dynamic mechanical analysis), taking tanδ's peak width and peak value as the research objects, the changing regularity of EPDM foamed material's damping property on processing conditions such as temperature and frequency and formula conditions such as foaming agent loading and filling agent loading was seeked for. The results showed that, with the raise of temperature and frequency, EPDM foamed material's damping property presented a tendency of rised first and descended aferwards. The EPDM foamed materials we prepared in this paper could gain the glassy temperatures ranged from-30℃to-4O℃,and the tanδpeak values ranged from 0.8 to 1.0, which met the special needs of damping materials, and could gain excellent damping properties under low temperature.