Nonisothermal crystallization of high density polyethylene and nanoscale calcium carbonate composites |
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| Authors: | Jiann‐Wen Huang Ya‐Lan Wen Chiun‐Chia Kang Wei‐Jen Tseng Mou‐Yung Yeh |
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| Affiliation: | 1. Department of Styling and Cosmetology, Tainan University of Technology, Taiwan, Republic of China;2. Department of Nursing, Meiho Institute of Technology, Neipu Hsiang, Taiwan, Republic of China;3. R&D Center, Hi‐End Polymer Film Co., Ltd., Taiwan;4. Department of Chemistry, National Cheng Kung University, Taiwan, Republic of China;5. Sustainable Environment Research Centre, National Cheng Kung University, Taiwan, Republic of China |
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| Abstract: | Nonisothermal crystallization of high density polyethylene (HDPE)/maleic anhydride‐modified HDPE(manPE)/nanoscale calcium carbonate (CaCO3) nanocomposite was investigated by means of wide angle X‐ray diffraction (WAXD), polarized optical microscopy (POM), and differential scanning calorimetry (DSC). WAXD indicated that the crystallinity was reduced with the addition of CaCO3. The spherulite size of HDPE increased in the presence of manPE, but decreased when CaCO3 was added from observation of POM. A modified Avrami analysis, Ozawa analysis, and Liu analysis were applied to the nonisothermal crystallization process. Crystallizability followed the order: HDPE/manPE/CaCO3 > HDPE/CaCO3 > HDPE/manPE > HDPE when undercooling was taken into account. Dependence of the effective activation energy on the relative crystallinity was estimated by the Friedman equation, and the results were used to calculate the parameters (Kg and U*) of Lauritzen‐Hoffman's equation by Vyazovkin's method. These results indicate that the addition of maleic anhydride groups and CaCO3 tend to promote the nucleation of spherulites on their surfaces and lead to epitaxial growth of the crystallites. But at the same time, manPE and CaCO3 particles may hinder the transport of the molecule chains resulting in a decrease of the crystallization growth rate. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers |
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