探討取代基誘導之共振效應對於聚苯基甲基丙烯醯胺衍生物其氫鍵作用行為之影響

Abstract

氫鍵作用力在高分子以及生醫材料領域當中扮演著非常重要的角色。即使到現在，有關氫鍵作用力的研究仍然持續進行當中。其中，許多在小分子中影響氫鍵作用力之因素，大部分皆已探討得非常詳盡，例如誘導取代機的影響，卻在巨分子或是高分子領域當中付之闕如。因此，我們設計了三種具有苯基之聚甲基丙烯醯胺，探討誘導取代基之共振效應對於氫鍵作用行為的影響。 在本研究中，藉由自由基聚合反應合成出聚苯基甲基丙烯醯胺poly(N-phenyl methacrylamide) (PPMA)、聚(對-甲氧基苯基甲基丙烯醯胺) poly(4-methoxyphenyl methacrylamide) (PMPMA) 和聚(對-溴基苯基甲基丙烯醯胺) poly(4-bromophenyl methacrylamide) (PBPMA)，並利用變溫傅立葉轉換紅外線光譜儀(FTIR)探討自身作用力及分子間作用力；發現PBPMA具有最強的自身作用力，而PPMA的自身作用力則是最弱的。而從微分掃描熱卡計(DSC)及紅外線光譜當中可以得知，PBPMA/P4VP混摻比PPMA/P4VP混摻更具有較強的分子間氫鍵作用力。另外，經由13C 固態核磁共振光譜來計算自旋－晶格鬆弛時間(T1ρH)，由鬆弛時間得知PBPMA/P4VP 混摻具有最強的分子間作用力，而在PPMA/P4VP混摻之分子間作用力是最弱的。最後，根據二維相關聯紅外線光譜顯示，誘導取代基之共振效應會影響自身氫鍵及分子內氫鍵強度，但是不會影響C＝O，N－H及吡啶之間氫鍵作用力形成和斷裂之次序。

The hydrogen bonding plays an important role in polymeric and biomedical material field. Within small molecules, the hydrogen bonding behaviors affected by delocalization have been studied thoroughly, but rare publication in macromolecules. Therefore, three poly(phenyl methacrylamide) with different inductive substitution in para position of benzene are prepared to investigate the substituent-induced resonance effect on the hydrogen bonding behaviors. In this thesis, the variable-temperature FTIR spectrum is used as tool to study the self-association and inter-association. The pyridine absorption and N－H stretching in FTIR spectra could provide a lot evidence that there is relatively stronger inter-associative hydrogen bonding in PBPMA/P4VP blends than that in PPMA/P4VP blends. Through 13C CP/MAS Solid State NMR Spectra, the spin-lattice relaxation time (T1ρH) indicates that PBPMA/P4VP blends possess the strongest inter-associative hydrogen bonding, also due to the enhancement by substituent inductive delocalization. Besides, 2D-correlation infrared spectroscopy reveals that the substituent-induced resonance effect does not affect the changing sequence of hydrogen bond breakage between C＝O, N－H and pyridine groups.