Use of gradient laminating to prepare NR/ENR composites with excellent damping performance

A novel processing method has been developed to broaden the damping temperature range of natural rubber (NR). Natural rubber and three kinds of epoxidized natural rubber (ENR, epoxidized degree: 25%, 40%, 50%) are arranged in a certain order to prepare NR/ENR-25/ENR-40/ENR-50 quaternary layered gradient material in a laminating way. By utilizing the relatively narrow Tg difference and the high compatibility between NR and ENR series, results show that the presence of three kinds of ENR can effectively broaden the effective damping temperature range (tanδ > 0.3) of NR. Specifically, the prepared NR/ENR-25/ENR-40/ENR-50 layered gradient material has the best damping performance due to the Tg superposition when the order of gradient superposition of epoxidized degree is adopted. Furthermore, the peak value of the loss factor (tanδmax) of layered gradient materials increases with the increment of layers, and when the layer number stands at 32, the peak of tanδ value can be as high as 1.815, covering an effective damping temperature range of 69.7 °C from −24.8 to 44.9 °C (tanδ > 0.3).