Many text books and publications do not focus on the necessity of chain tilting in crystalline lamellae of oligomers and polymers, a fundamental aspect of their crystallization already discussed by Flory. Herein we investigate the chain tilt of ethylene oxide oligomers (EOs) containing various midchain defects by WAXS, SAXS and solid state ¹³C MAS NMR spectroscopy. At low temperatures, one out of the two EO chains of EO₉-meta-EO₉ and EO₁₁-TR-EO₁₁ containing a 1,3-disubstituted benzene or a 1,4-disubstituted 1,2,3-triazole defect in central position of the oligomer chain forms crystals and the other EO chain as well as the defect remain in the amorphous phase. The aromatic midchain defect of these two oligomers can be incorporated into the crystalline lamella upon heating below T_m. Then, the adjoining amorphous EO chain crosses from the lamellae to the amorphous regions at an angle ξ, which is preordained by the substitution pattern of the aromatic defect, revealing that the chain tilt angle ranges between 36° ≤ ϕ ≤ 60°.

中文翻译：

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具有中链缺陷的环氧乙烷低聚物的链倾斜和结晶

许多教科书和出版物没有关注低聚物和聚合物的结晶薄片中链倾斜的必要性，弗洛里已经讨论过它们结晶的一个基本方面。在此，我们通过 WAXS、SAXS 和固态¹³ C MAS NMR 光谱研究了含有各种中链缺陷的环氧乙烷低聚物 (EO) 的链倾斜。在低温下，EO ₉ - meta -EO ₉和 EO ₁₁ -TR-EO _{11这两条 EO 链中的一条}在低聚物链的中心位置含有1,3-二取代苯或1,4-二取代1,2,3-三唑缺陷的低聚物形成晶体，而另一EO链和缺陷保持在非晶相中。这两种低聚物的芳族中链缺陷可以在加热到低于T _m时结合到结晶薄片中。然后，相邻的无定形 EO 链以角度 ξ 从片层交叉到无定形区域，这是由芳族缺陷的取代模式预先确定的，表明链倾斜角在 36° ≤ φ ≤ 60° 之间。