Effects of nano TiO2 on the light reflectivity, morphology, and rheological behavior of LLDPE‐glass bead composites

Heat-shield composites based on linear low density polyethylene (LLDPE) filled with micro-hollow glass beads (HGB) and TiO2 nanoparticles were prepared through melt compounding. Two kinds of LLDPE were used as the matrix of these composites with a fixed weight ratio of 60 : 40. HGB loadings were fixed at 28 wt % of LLDPE matrix while TiO2 content varied between 8 and 28 wt % of LLDPE matrix. Interestingly, the results show with addition of TiO2 to LLDPE-HGB composites, both the light reflectivity and the flow ability of composites show great enhancement. Especially when the TiO2 loading is 14 wt % of LLDPE, UV, and infrared reflectivity of the composites are more than 90%, showing a optimal heat-shielding performance, and the rheological responses including the storage modulus, G′ and the complex viscosities, |η*| of this composite are the lowest among all LLDPE/HGB composites. When TiO2 content is more than 14 wt %; however, ultraviolet radiation resistance is almost unchanged while that two dynamic rheological parameters increase gradually. It is proposed that the TiO2 loading of 14 wt % should be taken as the optimal value of a light reflectivity in LLDPE matrix, which is helpful in improving the processing ability by reduction in melt viscosity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012