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A thermal method for quantitatively determinating the content of short chain branching in ethylene/α-olefin copolymers

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Abstract

A quantitative method including peak-fitting for determination of the content of short chain branching (SCB) in ethylene/α-olefin copolymers based on differential scanning calorimetry is described. After stepwise isothermal crystallization, the fractions with similar SCB and lamellar thickness are sorted into groups. The content of each group is determined using the peak-fitting area. The statistical terms, the arithmetic mean SCB content \( \overline{C}_{\text{n}} \), the weighted mean SCB content \( \overline{C}_{\text{w}} \) and the branching broadness index \( I = \overline{C}_{\text{w}} /\overline{C}_{\text{n}} \) are calculated. Through comparing with the SCB contents measured by 13CNMR analysis, the results show that this method can quantitatively characterize the content of SCB in ethylene/α-olefin copolymers with a high degree of accuracy.

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Acknowledgements

The authors are grateful to the National Natural Science Foundation of China (Grant Nos. 50973074 and 51073110), Program for Sichuan Provincial Science Fund for Distinguished Young Scholars (2010JQ0014) and the Fundamental Research Funds for the Central Universities (Grant no. 2011SCU04A03) for the financial support. We also thank China Petroleum Chemical for supplying all the samples in this work. Yuan-ming Zhai would like to acknowledge China Scholarship Council for providing a scholarship during studying in Royal Melbourne Institute of Technology University.

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  1. State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu, 610065, Sichuan, China

    Yuan-Ming Zhai, Yu Wang, Wei Yang, Bang-Hu Xie & Ming-Bo Yang

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  1. Yuan-Ming Zhai
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  2. Yu Wang
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  3. Wei Yang
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Correspondence to Wei Yang.

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Zhai, YM., Wang, Y., Yang, W. et al. A thermal method for quantitatively determinating the content of short chain branching in ethylene/α-olefin copolymers. J Therm Anal Calorim 110, 1389–1394 (2012). https://doi.org/10.1007/s10973-011-2054-z

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  • DOI: https://doi.org/10.1007/s10973-011-2054-z

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