Preparation And Properties Of Titanium Dioxide/polycarbonate Light Reflection Composites

Light reflection film plays an important role in light source through the LCD display module, its function was to reflective light from the back light source to the light direction, thus could improve the back-light brightness. Currently, the main light reflection film contains polypropylene(PP) light reflecting film, polyethyleneterephthalate(PET) reflective film and polycarbonate(PC) light reflecting film, the PC had high light transmittance, good coloring, good heat resistance and hard to deformation, etc. Titanium dioxide(Ti O2) was a kind of pigment with the highest refractive index in the nature, had the properties of stability, high whiteness to visible light absorption characteristics, widely used in paint, cosmetics, light reflex, and other fields. So the Ti O2 was always used in PC to preparation materials which had high research value and prospect. But because of the special properties of the Ti O2 surface, when it blending with PC will accelerate the thermal degradation reaction of PC, so the Ti O2 surface modification treatment was urgent required.This paper studies thermal degradation of PC which was influenced by Ti O2, the surface modification methods of Ti O2 and the preparation of Ti O2 / PC composites; Using contact angle measurement instrument, UV-Vis spectrometer, Fourier infrared spectrum analyzer to test the performance of Ti O2 powder, with the melt flow rate instrument and torque rheometer to melt properties of PC/Ti O2 composite materials were tested, and preparing composite materials into film, optical properties of thin films were tested by ultravioletvisible spectrometer.The experimental results showed that pure Ti O2 will last weightlessness within 600 heating process; PC/Ti O℃2 composite materials melt flow rate was increased with the increase of the amount of Ti O2 and the rising of temperature; Melt torque was decreased with the increase of the amount of Ti O2 and the rising of temperature, showed that the amount of Ti O2 and processing temperature significantly affected the melt properties of PC/Ti O2 composite materials.Contact angle of Ti O2 had no obvious changing, after modified with Si O2 and Al2O3; Compared with Ti O2/PC composites with pure Ti O2, melt flow rate of Ti O2/PC composites with Ti O2 modified with Si O2 was reduced, melt flow rate of Ti O2/PC composites with Ti O2 modified with Al2O3 have no obvious changing.Modified Ti O2 with epoxy resin and organic silicone, contact angle of Ti O2 modified with the epoxy resin changed from 0 ° to 99.6 °, and compared to Ti O2/PC composites with pure Ti O2, melt flow rate of Ti O2/PC composite materials with modified Ti O2 significantly decreased, but its color change into yellow; Contact angle of Ti O2 modified with organic silicon changed from 0 ° to 133.3 °, melt flow rate of PC/Ti O2 composite materials obviously decreased and its torque increased, thermal stability of PC was improved.Formulation and preparation process of surface modified with organic silicon was: coated amount was 6%, the viscosity of silicone was 3000 mpa.s, curing time silicone was 3 h, Ti O2 modified in this way had reflection of 96.6%, melt flow rate of 6.91 g/10 min, and the light reflection film had a reflection of 95.8%.