Abstract
We apply gamma ray irradiation from 250 kGy to 1000 kGy on Poly(4-methyl-l-pentene) (commercial name is TPX) specimens in air and oxygen environment. During DSC tests, we set different cooling rates to measure the data of TPX specimens. We proceeded the cooling rate by 1℃、2.5℃、5℃、10℃、20℃、40℃ and 60℃ per minute. The DSC data indicated that the specimens with low gamma-ray dose have large peak which is clear to see, and in high gamma-ray dose the peak become small and not easy to see, especially the specimens irradiated in oxygen environment. In order to proceed the non-isothermal crystallization kinetics of irradiated Poly(4-methyl-1-pentene), we separate the double peak curve by modified Gaussian equation with gama distribution . For TPX non-isothermally crystallized by cooling at constant rates, we can find exponent n in Ozawa plots with two tendencies. One is that Ozawa exponent n decreases with decreasing crystallization temperature for the same interval of cooling rates, the other is the exponent n increasing with increasing cooling rates. We have a conclusion that Ozawa apparach method can not meet the high cooling rates data. For the study of Poly(4-methyl-l-pentene), it can be seen that Ozawa exponent n increases with increasing crystallization temperature, n is almost from 1.0 to 3.0, which means the pre-determined nuclei might exist before cooling.