Confined intra-molecular clustering in orientated polyethylene after annealing

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• 作者：Yongfeng Men ; Jens Rieger ; Peter Lindner ; Hans-Friedrich Enderle ; Dieter Lilge ; Marc-Oliver Kristen ; Shahram Mihan ; Shichun Jiang
• 关键词：SANS ; Polyethylene ; Deformation
• 刊名：Polymer
• 出版年：2007
• 出版时间：24 April 2007
• 年：2007
• 卷：48
• 期：9
• 页码：2464-2469
• 全文大小：2323 K

文摘

Deuterated polyethylene tracer molecules with small amount of branches (12 C₂H₅– branches per 1000 backbone carbon atoms) were blended with a hydrogenated polyethylene matrix to form a homogenous mixture. The conformational evolution of the deuterated chains in a stretched semi-crystalline film was observed via online small angle neutron scattering measurements during annealing at high temperatures close to the melting point. Because the sample was annealed at a temperature closely below its melting point, the crystalline lamellae were only partially molten and the system could not fully relax. The global chain dimensions were preserved during annealing. Recrystallization of released polymeric chain segments allows for local phase separation thus driving the deuterated chain segments into the confining inter-lamellar amorphous layers giving rise to an interesting intra-molecular clustering effect of the long deuterated chain. This clustering is deduced from characteristic small angle neutron scattering patterns. The confined phase separation has its origin in primarily the small amount of the branches on the deuterated polymers which impede the crystallization of the deuterated chain segments.