Thermal aging on mechanical properties and crosslinked network of natural rubber/zinc Dimethacrylate composites

Abstract

This article dealt with the relationship between mechanical properties and crosslinked networks of natural rubber (NR) reinforced by zinc dimethacrylate (ZDMA) after thermal aging. After thermal aging at the present experimental conditions, the covalent crosslink density showed a decrease all the time, whereas the ionic crosslink density was stable at 80C but decreased at a higher temperature. The decrease in the total crosslink density after aging indicates the degradation of the crosslinked network. However, an experimental phenomenon observed was that the tensile strength and tear strength increased in a certain degree after aging at 80 C or at a 100 C for a short time. In addition, the thermal stability of the NR/ZDMA composite was evaluated by thermal gravimetric analysis.

Temperature dependence of the mechanical properties and the inner structures of natural rubber reinforced by in situ polymerization of zinc dimethacrylate

“…All the stress–strain curves (≥80°C) are almost linear, showing no signs of strain‐induced crystallization. In our previous study,16 we found that the ionic crosslinks were relatively stable at 80°C. Thus, the crosslink structure is mainly to afford the tensile stress at this temperature.…”

“…Although tensile strength of all the NR/ZDMA composites is decreasing with increasing temperature, the high temperature tensile strength is improved apparently with high ZDMA loading level (Table I). This suggests the possibility of ZDMA to improve the high temperature performances of rubbers 16…”

“…Corresponding to the TG curves, the DTG curves [Figure 12(b)] for the composite samples are characterized by two degradation peaks, but only one maximum for NR sample, which indicates the existence of different degradation. For the NR/30 phr ZDMA composite, the first degradation peak is attributed to the degradation of NR matrix and second degradation peak is attributed to the degradation of PZDMA 16. In addition, the weight drop of NR/30 phr ZDMA composite is highlighted compared to NR.…”

“…As known to us, the majority of the reports about ZDMA-reinforced rubbers are carried out at the room temperature, and few publications concern the properties at higher temperatures. Our previous work 16 studied the effects of thermal aging on the mechanical properties of the natural rubber (NR)/ZDMA composites and revealed that the ionic crosslinked network was ruptured after aging at a high temperature and the covalent crosslinked network was mainly to support the mechanical properties of the composite this moment. But how does the NR/ZDMA composite performs in high temperature applications?…”

Influence of rubber and fabric cord on deformation of a fabric cord-inserted rubber composite by thermal aging

“…One of the principal reasons regarding permanent deformation of a rubber vulcanizate is change in crosslink density [3]. Thermal aging causes the crosslink density of a rubber vulcanizate to change [1,[4][5][6][7][8][9].…”