Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5204746 | Polymer Degradation and Stability | 2007 | 14 Pages |
Thermal behaviors of polymer blends between common-type polybenzoxazine (PBA-a) and polysiloxane-block-polyimide (SPI) were studied using Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA). The polymer blends showed only one glass-transition temperature (Tg) that increased as the content of SPI increased. Synergistic behavior in the char formation of the alloys was clearly observed. The DTG curves showed three stages and two stages of decomposition reaction in neat PBA-a and SPI, respectively. For the blending systems with 25Â wt%, 50Â wt%, and 75Â wt% of SPI, the DTG thermograms of the blends exhibited four stages of thermal decomposition reaction. The apparent activation energies (Ea) of each step were determined using Kissinger method, Flynn-Wall-Ozawa method and Coats-Redfern method. The type of solid state mechanism was determined by Criado method. From the calculation, the solid state thermal degradation mechanism is proposed to be F1 (random nucleation with one nucleus on the individual particle) type for PBA-a, SPI, and their blends.