3.3.4. Tensile Property. The tensile performance has been investigated in detail among different samples, namely,NR, NR/PMMA, NR-PMMA/SiO2, and NR-PMMA/SiO2-PMMA. Obviously, with the improvement of modification and the introduction of nanosilica, the tensile strength as well
as tensile modulus at different elongations is increasingly high. It can be seen from Table 1 that the tensile strength increases by 3.66 MPa from 6.99 MPa (NR) to 10.65 MPa (NR-PMMA/SiO2-PMMA). Since PMMA is grafted both on SiO2 and NR, its molecule chains twist together via similardissolve mutually theory, reinforcing the interaction between nano-SiO2 and NR matrix and hindering the movement of NR macromolecule chains [37]. That is to say that
PMMA as a bridge between the inorganic nanoparticles andpolymer matrix improve the mutual compatibility which in turn results in excellent mechanical property. In addition, comparing the tensile strength between NR-PMMA and NR-PMMA/SiO2, nanosilica without grafting PMMA on itssurface can also reinforce the tensile property, from 7.23 to8.95 MPa.