| Summary: | 碩士 === 逢甲大學 === 化學工程學所 === 92 === Abstract
The bulk photo- polymerization of 2-hydroxyethyl methacrylate (HEMA), cyclohexyl methacrylate (CHMA), 2-hydroxypropyl methacrylate (HPMA) and 4-hydroxybutyl methacrylate (HBMA), using 2,2-Diethoxyacetophenone (DEAP) as initiator were conducted. The data of average life time of a growing radical (τs) were obtained by using rotating sector method, where the light source was a mercury lamp (UVP 100W, wavelength of 365 nm) equipped with a filter. Besides, 4-Methoxyphenol (MEHQ) was used as inhibitor to determine the rate of inhibition.
Values of polymerization rate(Rp) of HEMA, CHMA, HPMA and HBMA was determined to be 0.321, 2.50, 3.87 and 4.34×10-4 mol∙L-1∙s-1, respectively, and the initiating rate(Ri) are 4.74, 3.05, 5.47 and 4.31×10-7 mol∙L-1∙s-1, respectively. Using the rotating sector method at 30℃, the τs values were estimated to be 0.111, 0.152, 0.132 and 0.172 s, respectively.
Finally, the rate coefficient of propagation (kp) of HEMA, CHMA, HPMA and HBMA were found to be 71.9, 1070, 640, and 917 L∙mol-1∙s-1 and the rate coefficient of termination (kt) to be 8.56, 9.30, 3.99, and 4.02×107 L∙mol-1∙s-1, respectively.
Varying the distance of the light source can vary the light intensity. The polymerization rate increases with light intensity, and the order dependence is close to 0.5.
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