EFFECT OF IN SITU SURFACE-MODIFIED NANO–ZINC OXIDE ON THE STRUCTURE AND PROPERTIES OF CONVENTIONAL VULCANIZATION IN NATURAL RUBBER

Abstract

ABSTRACT In situ surface-modified nano–zinc oxide (ZnO) had been prepared by the sol-gel method. The microscopic structure of the ZnO particles was characterized by X-ray diffraction and transmission electron microscopy. Scanning electron microscopy with energy-dispersed X-ray spectroscopy was used to observe the dispersal of ZnO in conventional vulcanization of natural rubber (NR). Properties such as cure and tensile characteristics as well as heat-resistance oxygen aging properties were researched and compared. The vulcanized structure of vulcanizate was studied by the balance-swelling method and chemical-detecting process. Results demonstrated that the dispersal of in situ surface-modified nano-ZnO in NR vulcanizate was better than that of ordinary ZnO. Compared with the addition of 5 phr of ordinary ZnO in NR, the tensile strength and elongation of NR vulcanizate filled with 2 phr of in situ surface-modified nano-ZnO increased by 0.55% and 10.34%, respectively. Meanwhile, the retention of tensile strength and elongation of vulcanizate increased by 35.85% and 19.36%, respectively.