Study Of The UFPCSBR/SiO₂ Nanocompound On The Fabrication Of Rubber Nanocomposites

The ultrafine fully-vulcanized carboxylated styrene butadiene rubber (UFPCSBR)/nanosized silica (SiO2) nanocompound powder is a novel nanoscale nanocompound in which the UFPCSBR particles and SiO2 particles are isolated and adhered to each other. When the UFPCSBR/SiO2 nanocompound is mixed with SBR/NR compound, the SiO2 particles are easily dispersed well in rubber matrix due to the good compatibility between UFPCSBR particles and rubber, leading to some super properties of the modified SBR/NR composites.In this article we prepared some UFPCSBR/SiO2 nanocompound powder while studying the synergism effects of the UFPCSBR/SiO2 nanocompound and the UFPNBR powder on some properties of the modified SBR/NR composites for tread rubber.The synergism effects of the UFPCSBR/SiO2 (wt/wt/=6/5) nanocompound powder and the UFPNBR powder on some properties of the modified SBR/NR composites are studied first. Experimental results show that, compared to neat SBR/NR composites, the SBR/NR composites modified with the UFPCSBR/SiO2 nanocompound powder and UFPNBR have higher tensile stress, hardness, tear strength and the elongation at break while the aging property is increased too. Of note, the second peak of Tanδ-T curve of the SBR/NR composites modified with the UFPCSBR/SiO2 nanocompound and UFPNBR shift to 0℃, leading to increased Tanδ values near 0℃, which explains that the UFPCSBR/SiO2 nanocompound and UFPNBR have the synergism on improving the wet skid resistance of SBR/NR composites used for tread compound, and it is very important to both the research and industry application of tread compound.In order to further study the effects of other kinds of UFPCSBR/SiO2 nanocompound powder (with different component of UFPCBSR and different consitution of the UFPCSBR/SiO2 nanocompound powder) on some properties of the modified SBR/NR composites. This paper fabricated other two kinds of UFPCSBR/SiO2 nanocompound powder in which the the weight ratios of UFPCSBR to SiO2 are 3/1 and 3/4 respectively, and the styrene content in the UFPCSBR particles is 50%. The SEM images show that the nanoscale SiO2 particles have good dispersion in the UFPCSBR/SiO2 (3/1) nanocompound powder; when the weight ratio of UFPCSBR to SiO2 increased to 3/4, there are some small aggregations of SiO2 particles while most of the UFPCSBR particles and SiO2 particles are dispersed well in the UFPCSBR/SiO2 (3/4) nanocompound powder. Compared to the SBR/NR composites modified with the mixture of UFPCSBR powder and SiO2 powder, the Tc90 value of the SBR/NR composites modified with the same loading of UFPCSBR/SiO2 (3/1) nanocompound powder decresed by 61s, and the Akron Abrassion value decreased by 0.79 cm3/1.61km. In the Tanδ-T curve of SBR/NR composies modified with the UFPCSBR/SiO2 (3/4) nanocompound powder, there appeared two Tanδ peaks near-10℃ and 42℃, respectively, thus leading to the increased Tanδ values in 0℃ and 60 ℃, which means that the synergism of the UFPCSBR/SiO2 (3/4) nanocompound and UFPNBR has the effects on improving the wet skid resistance and rolling resistance of the SBR/NR composites, and the reason why the Tan8 values of the SBR/NR composites modified with UFPCSBR/SiO2 (3/4) nanocompound and UFPNBR increase in 60℃ can be explained by the increasing of styrene content of the UFPCSBR.