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首页> 外文期刊>Journal of Molecular Structure >A study of diffusional behavior of polymer having semiflexible main-chain with long n-alkyl side-chains as associated with structural behavior of the side-chains
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A study of diffusional behavior of polymer having semiflexible main-chain with long n-alkyl side-chains as associated with structural behavior of the side-chains

机译：具有半挠性主链和长正烷基侧链的聚合物的扩散行为与该侧链的结构行为相关的研究

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摘要

Structural and dynamic characterizations of poly(n-octadecyl methacrylate)(PODMA) have been made at -8.2 and 13.6 °C below the melting temperature (T_m) of the n-octadecyl side-chain crystallite and at temperatures from 25.8 to 65 °C above the T_m of the n-octadecyl side-chain crystallite by ~(13)C CP-MAS NMR, and have been made at temperatures from 30 to 80 °C by ~(13)C DD-MAS NMR, respectively. Also, the ~1H T_2s of the n-octadecyl side-chain have been measured as a function of temperature in the temperature range from 20 to 80 °C by ~1H spin-echo ~1H NMR, and its dynamic behavior has been studied. Further, diffusional behavior of PODMA chains in the molten state at temperatures above the T_m of the n-octadecyl side-chain crystallite has been elucidated through determination of the diffusion coefficients (Ds) by means of pulsed field-gradient stimulated-echo (PFGStE) ~1H NMR method. The existence of the two kinds of the D_(slow) component with the order of 10~(-11)-10~(-10) cm~2 s~(-1) as the major component and the D_(fast) component with the order of 10~(-7) cm~2 s~(-1) as the minor component in diffusion process of PODMA chains in the molten state has been shown and further their diffusion behaviors have been discussed.
机译：聚甲基丙烯酸正十八烷基酯（PODMA）的结构和动态表征是在低于正十八烷基侧链微晶的熔融温度（T_m）的-8.2和13.6°C以及25.8至65°C的温度下进行的通过〜（13）C CP-MAS NMR在n-十八烷基侧链微晶的T_m之上，并通过〜（13）C DD-MAS NMR在30至80°C的温度下分别制得。另外，通过〜1H自旋回波〜1H NMR测定了在20〜80℃的温度范围内正十八烷基侧链的〜1H T_2s与温度的关系，并对其动态行为进行了研究。此外，已经通过借助于脉冲场梯度受激回波（PFGStE）测定扩散系数（Ds）阐明了在高于正十八烷基侧链微晶T_m的温度下熔融态PODMA链的扩散行为。 〜1H NMR方法。以10〜（-11）-10〜（-10）cm〜2 s〜（-1）为主要成分的两种D_（slow）成分和D_（fast）成分的存在以10〜（-7）cm〜2 s〜（-1）的量级作为PODMA链在熔融态扩散过程中的次要成分，并对其扩散行为进行了讨论。

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