調控特殊作用力在相容性半結晶性團聯式共聚物與均聚物混摻系統之自組裝微結構研究

Abstract

本研究中，成功的利用開環配位聚合和可控制活性自由基聚合合成出多種鏈段比例的poly(ε-caprolactone)-b-(vinyl phenol)可相容性的半結晶高分子，然後將合成的團聯式共聚物摻混均聚物聚乙烯必喀烷酮poly(vinyl pyrrolidone) (PVP)藉由A-B/C形式的氫鍵特殊作用力調控相行為變化。利用傅立葉轉換紅外線光譜(FTIR)去討論不同摻混比例下的氫鍵作用力，微分掃描卡計分析(DSC)清楚判斷PVP的羰醯胺基氫鍵受體(aceptor)強於PCL的羰基(aceptor)作用於氫氧基施予體(donor)，使得PCL被排相於PVPh/PVP相，我們以固態NMR來證明摻合物中有兩個以上的T1ρ(H)值，其代表的是微相分離存在於氫鍵摻混系統，小角度散射實驗顯示長周期高階散射峰散射向量比例為:1:2:3，為一個層狀結構符合穿透式電子顯微鏡(TEM)，隨著增加PVP的含量，其最後的相行為及形態可能從層狀轉變成圓柱。

A series of miscible crystalline-amorphous diblock copolymer (poly(ε-caprolactone)-b-(vinyl phenol), PCL-b-PVPh) were prepared through combinations of sequential ring-opening and controlled living free radical (nitroxide-mediated) polymerizations and then blended with poly(vinyl pyrrolidone) (PVP) homopolymer. Specific interactions, miscibility, and self-assembly morphologies, mediated by hydrogen bonding interactions of this new A-B/C type blend, are discussed in details. Micro-phase separation would possible occurs of these miscible PCL-b-PVPh diblock copolymers through compete hydrogen bonding interaction with the increase of PVP contents. FTIR, XRD and DSC analyses provide positive evidences that the carbonyl amide group of PVP is the significantly stronger hydrogen bond acceptor than the carbonyl group of PCL with the hydroxyl group of PVPh, which results in the excluded PCL block and then form the self-assembly structure from PVPh/PVP miscible phase. 13C CP/MAS solid-state NMR spectra provide additional evidence confirming that micro-phase separation are taking place for the blends system because of more than two T1ρ(H) values for this A-B/C blend system. The SAXS profiles also reveal a sharp primary peak and highly long range order reflections q/q* ratios of 1:2:3 at relatively lower PVP content, which indicate the lamellar structure in the blend system, which is consistent with TEM image. The final phase behavior and morphology would change to cylinder structure with the increase of PVP content.