Abstract: The PUF/TiO₂ composites were prepared by in-situ polymerization, the effects of the addition of titanium dioxide on properties of PUF for packaging were investigated. It was characterized by SEM, TG/DTG, DSC and FTIR. The results show that when the dosage of TiO₂ was 4% of the total amount of reagents, the optimum compression strength of PUF/TiO₂ composites is 24.33 MPa, which is 1.63 times higher than that of PUF. DSC and TG/DTG results show that the addition of nano TiO₂ is beneficial to improve the thermal stability of PUF. After adding 4% nano TiO₂, the initial decomposition temperature of PUF is increased from 241.5 ℃ to 263.4 ℃, and the maximum weight loss rate increases from 324.73 ℃ to 334.86 ℃. FTIR show that the absorption peak of Ti-O was found at about 653 cm^-1 in PUF/TiO₂ composites, indicating that TiO₂ was successfully linked to the polymer chain segment of PUF. The results of SEM show that the nano TiO₂ is uniformly distributed in the matrix of PUF and has been embedded into the foam structure of PUF.