
Abstract According to the literature, different types of materials have different glass transition temperature ( T g ) dependences of apparent activation energy ( E g ) and dynamic fragility ( m ). In previous work we found that for different ambers, there were different glass transition temperatures. These same samples provide an opportunity to study the T g dependence of E g and m for amber, which has not been reported previously in the literature. In this work, nine pieces of amber from different locations and having different ages were investigated by differential scanning calorimetry. Six cooling rates were used to provide the different thermal histories, and the corresponding limiting fictive temperatures were determined using Moynihan's area matching method. From the cooling rate dependence of the limiting fictive temperature both the apparent activation energy and dynamic fragility were calculated. We find that as glass transition temperature increases, both the apparent activation energy and dynamic fragility increase. The T g dependence of m for amber shows a similar trend with temperature as do the metallic glass formers and compares favorably with the m – T g dependence of other aromatic polymers.
[CHIM.POLY] Chemical Sciences/Polymers, [SPI] Engineering Sciences [physics], [CHIM] Chemical Sciences, [SPI.MAT] Engineering Sciences [physics]/Materials, [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat], [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS] Physics [physics]
[CHIM.POLY] Chemical Sciences/Polymers, [SPI] Engineering Sciences [physics], [CHIM] Chemical Sciences, [SPI.MAT] Engineering Sciences [physics]/Materials, [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat], [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS] Physics [physics]
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