The effects of natural astaxanthin-modified silica on properties of natural rubber

Natural astaxanthin is a natural substance extracted from algae such as Haematococcus pluvialis. Its molecular structure contains conjugated double bonds as well as keto and hydroxyl groups, and therefore it has high activity. In this research, natural astaxanthin was used to modify the surface of the silica, and its effects on natural rubber vulcanization properties, physical and mechanical properties, dynamic properties, and antiaging properties were studied by means of rubber process analyzer, dynamic mechanical anaylsis, and scanning electron microscopy. The results showed that natural astaxanthin-modified silica could reduce the degree of delayed vulcanization. At the same time, the resilience and abrasion resistance of the obtained vulcanizates were increased. The DIN abrasion volume of the vulcanizates modified and reinforced by the second strategy decreased by 19.2% and 23.6%, respectively; the Payne effect of the natural astaxanthin-modified silica/NR composites was weakened, and the dispersibility of the filler and the compatibility with the rubber matrix was significantly improved. Regardless of which strategy was used to modify the silica, the vulcanizates had a lower rolling resistance. Specially, it could greatly improve the hot air aging resistance property of rubber. Natural astaxanthin as being a renewable feedstock is expected to have a quite broad applications in the rubber industry. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 136, 47287.