Time-resolved SAXS studies of morphological changes in a blend of linear polyethylene with homogeneous ethylene-1-octene copolymer
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- 作者：Czesław Ślusarczyk ; cslusarczyk@ath.bielsko.pl" class="auth_mail" title="E-mail the corresponding author
- 关键词：Isothermal crystallization ; Polyethylene blends ; Nanostructure evolution ; Time-resolved small-angle X-ray scattering ; Synchrotron radiation
- 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
- 出版年：2015
- 出版时间：1 December 2015
- 年：2015
- 卷：364
- 期：Complete
- 页码：116-119
- 全文大小：465 K
文摘
Isothermal melt crystallization in the 15/85 (m/m) blend of a high density polyethylene (HDPE) and a homogeneous ethylene copolymer with 5.5 mol% 1-octene was studied by time-resolved SAXS method with synchrotron radiation over a wide-range of crystallization temperatures. The SAXS profile was analyzed by means of the correlation function which allows to elucidate the evolution of the morphological parameters of polyethylene lamellar structure (long period (LP), thicknesses of crystalline (LC) and amorphous (LA) layers) during a crystallization process. It was found that for the samples crystallized at 100 °C, 120 °C and 122 °C LC increases with time. The lamellar thickening rate strongly depends on crystallization temperature. At 40 °C thickening of the crystalline layers does not occur.
The time evolution of the lamellar structure in the blend studied confirms the role of hexyl branches of homogeneous copolymer in the crystallization process of polyethylene. The branches introduce steric constraints which hinder the crystallization of HDPE, thus decreasing the size of the HDPE lamellar crystals.