관류형 반응기 시스템을 이용한 옥실란 유도체와 스타이렌계 단일 중합체 및 블록 공중합체의 합성에 관한 연구

Abstract

본 연구의 목적은 이온 중합 시스템의 구축과 이를 이용하여 산업 적용성을 고려한 글리시딜 아자이드 폴리머 (GAP)계열의 다양한 종류의 블록 공중합체를 합성하는 기술 개발에 있다. 제 2장에서는 에피클로로히드린 (ECH)을 반응 설정온도와 촉매 대 개시제 비, 그리고 단량체 투입속도를 변수로 하여 양이온 개환 중합하는 연구를 진행하였다. 개시제는 1,4-부탄디올 (BD)를 촉매는 보론트리프로라이드 (BF₃)를 사용하였다. 폴리에피클로로히드린 (polyepichlorohydrin, PECH) 의 중합반응열 거동과 품질에 연관성이 있다는 것을 실시간 반응온도 모니터링 시스템과 GPC, ¹H-NMR, 그리고 FTIR 분석을 통해 확인하였다. 중합반응 중, 분자량 분포도에 영향을 주는 유도기 (induction period)가 중합온도 10℃ 이하에서 관찰되었고 온도와 촉매/개시제 비가 낮을수록 유도기는 증가하였다. 단량체 투입 속도는 유도기에는 영향을 주지 않았으나 유도기가 관찰되는 중합 조건에서는 PECH의 분자량 분포도에 큰 영향을 주었다. 반응 설정 온도가 낮아 질수록 낮은 분자량을 가지는 고리형 올리고머의 함량이 증가함에도 불구하고 PECH의 분자량은 증가하였다. 제3장에서는 PECH를 중합하는 조건으로 개시제-촉매 축합체의 용매에 대한 용해도가 유도기 (induction period)에 미치는 영향을 연구하였다. 중합 조건은 개시제의 종류 (1,4 부탄디올 [BD], 디에틸렌글라이콜 [DEG])와 촉매 대 개시제의 비율을 달리하여 진행하였다. 또한 DEG를 개시제로 사용하여 PECH를 중합할 시 중합 조건을 최적화 하기 위하여 반응 설정 온도와 단량체의 투입 속도가 중합체에 미치는 영향을 추가적으로 연구하였다. 이를 위해 온도와 토크를 실시간으로 관찰 할 수 있고 중합 조건을 일정하게 유지하고 조절 할 수 있는5 리터 3중 자켓 반응기 시스템을 구축하였다. 용매로 사용하는 메틸렌 클로라이드 (MC)에 용해되지 않는 BD-BF3 축합체를 사용하여 PECH를 중합 할 시에 긴 유도기 이후에 제어할 수 없을 정도로 높은 발열 반응이 짧은 시간 동안에 나타났다. MC에 용해되는 DEG-BF₃ 축합체를 사용하였을 때에도 유도기가 관찰 되었으나 이후 나타나는 발열 반응은 반응기 시스템으로 제어가 가능하였고 중합체의 분자량 분포도 또한 BD-BF3 축합체를 사용할 때보다 낮은 값 (1.31 – 1.34)을 가졌다. 반응 용액의 용해력에 영향을 받는 유도기는 온도와 촉매 개시제비가 낮을수록 증가하였다. 제 4장에서는 스타이렌 (S), 메틸 메타아크릴레이트 (MMA) 그리고 2-비닐 피리딘 (2VP)을 상업 생산 공정 적합성을 고려한 음이온 중합 법으로 1 리터 상압 중합 반응기를 이용하여 중합하였다. 다이페닐헥실리튬 (DPHLi) 개시제와 THF 용매를 사용하고 냉각된 단량체를 투입하는 방법을 이용하여 순차 등온 상태에서 좁은 분자량 분포도 (1.05 ≤ Mw/Mn ≤ 1.17) 를 가진 PS-b-PMMA와 PS-b-P2VP 공중합체를 중합하였다. PS 블록은 -15 ℃ 와 -25 ℃ 에서 중합하였고 PS-b-P2VP와 PS-b-PMMA의 두 번째 블록은 -78 ℃ 에서 중합하였다. 비활성 기체 환경을 가지는 모듈타입 상압 중합반응시스템으로 중합반응이 진행되는 동안 이의 온도와 토크를 관찰 할 수 있었다. 중합 발열 반응을 제어하기 위하여 두 번째 블록의 단량체는 약 -30 ℃ 로 냉각한 후에 반응기에 투입하였고 이 방법을 사용함으로써 반응기의 최대 상승 온도를 최소화 (ΔTRMAX ≤ +11 ℃) 할 수 있었다. 제 5장에서는 THF를 용매로 사용하고 스타틱 믹서가 내장된 연속식 관형반응기를 이용하여 PS-b-PMMA 공중합체를 중합하는 연구를 실시 하였다. DPHLi 개시제를 사용하여 정밀하게 분자량이 제어된 중합체 [PS (Mn: 120 x 10^3 g•mol^-1, Mw/Mn: 1.08), PMMA (Mn: 28 x 10^3 g•mol^-1, Mw/Mn: 1.09), P2VP (Mn: 53 x 10^3 g•mol^-1, Mw/Mn: 1.08), 및 PS-b-PMMA (Mn: 117 x 10^3 g•mol^-1, Mw/Mn: 1.12)]를 얻을 수 있었으며 PS-b-PMMA 와 PMMA 그리고 P2VP는 중합시에 LiCl 첨가제를 사용하였다. 단량체의 투입속도를 조절함으로써 중합체의 분자량을 조절 할 수 있었고 혼합 효율과 관련된 중합체의 분자량 분포도는 관내 흐름 속도를 빠르게 할 수록 좁아졌다. 제 6 장에서는 제 3장과 제 5장에 소개된 양이온 개환 중합 반응 시스템과 음이온 중합 관형반응 시스템을 이용하여 에너지 함유 폴리 글리시딜 아지도 블록 폴리스타이렌 (GAP-PS) 공중합체를 합성하였다. 우선 음이온 중합 관형 반응 시스템을 이용하여 사슬 말단에 단일 에폭시 작용기를 가지는 폴리스타이렌 (ω-epoxy terminated polystyrene: EpPS)를 합성하였다. PS의 중합은 -25 ℃ 에서 실시하였고 에피브로모히드린 (epibromohydrin) 을 이용하여 에폭시 기를 도입하는 치환반응은 -78 ℃ 에서 순차적으로 실시 하였다. PECH는 트리프로필렌 글라이콜-BF₃ (TPG-BF₃) 축합물을 이용하여 active monomer 메커니즘으로 반응을 유도하며 중합하였고 PECH 중합이 완료된 후에 여기에 EpPS를 BF₃가 존재하는 상태에서 투입하여 PECH-b-PS를 합성하였다. EpPS의 양이 개시제 (TPG) 를 기준으로 0.5 몰비 이상일 때 PS-PS coupling 중합체가 전체 중합체 내에 일부 생성되었다. GAP-PS는 PECH-PS의 Cl기를 N₃로 치환 반응 (azidation) 시켜 얻었다. PECH-PS의 열적 거동 분석에서 PECH는 PS와 상용성 (compatibility)이 있는 것으로 나타났으나 azidation 후에는 -N₃기로 인한 극성 변화로 상용성이 감소하였다.|The aim of this research is to development of controlled ionic polymerization system for synthesis of GAP based block copolymer with various specifications and consideration of industrial applicability. In chapter two, cationic ring opening polymerization of epichlorohydrin (PECH) produced under various reaction conditions (set temperature: -10-40 ℃, [C]/[I] ratio: 0.1-1, monomer feed rate: 1-4 mL•min^-1) was investigated. In addition, a correlation between the exothermic reaction temperature and the performance of the PECH was obtained by utilizing a reaction temperature monitoring system, GPC, ¹H-NMR, and FTIR. During the polymerization, an induction period which affects the molecular weight distribution was observed below 10 ℃. At lower temperatures and lower [C]/[I] ratios, a higher induction period was observed. The monomer feed rate did not affect the induction period but it highly affected the molecular weight distribution when the induction period occurred. The total molecular weight of PECH increased with decreasing set temperature even though the amount of low molecular weight cyclic oligomer increased. In chapter three, the effect of initiator diol- BF₃ complex solubility on an induction period was investigated for BF₃ catalyzed cationic ring opening polymerization of epichlorohydrin at various [BF₃]/[initiator diol] ([C]/[I]) ratios, using on-line temperature and torque monitoring systems. Other factors influencing the induction period (reaction temperature: -5 – 30 ℃, [C]/[I] ratio, and monomer feed rate: 9.2 x 10^-3 – 27.6 x 10^-3 mol•min^-1) were also investigated in order to optimize the polymerization condition in the presence of the diethylene glycol (DEG)-BF₃ complex. A 5-L, triple-glass jacket reactor was customized for the monitoring system. 1,4 Butanediol (BD) and diethylene glycol (DEG) were used for the initiator diol. In the presence of the BD-BF₃ complex, which is insoluble in methylene chloride solvent (MC), an uncontrollable and highly exothermic reaction occurred shortly after the long induction period. There was an induction period with the DEG initiator diol as well, but the exothermic reaction which followed was much more controlled, and the resulting polymers showed relatively narrow polydispersities (1.31 – 1.34) using DEG initiator diol, which is soluble in MC. The longer induction period, which was highly affected by the solvation effect of the reaction media appeared at lower reaction temperature and lower [C]/[I] ratio. In chapter four, anionic polymerization of styrene, methyl methacrylate and 2-vinyl pyridine using 1 L scale module type batch reactor with consideration of industrial applicability was introduced. Poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and poly(styrene-b-2-vinyl pyridine) (PS-b-P2VP) block copolymers with narrow molecular weight distributions (1.05 ≤ Mw/Mn ≤ 1.17) were achieved via a pre-cooled monomer addition method using a diphenyl hexyl lithium initiator in tetrahydrofuran under sequential isothermal conditions. The styrene block was polymerized at -25 ℃ and -15 ℃, and the second block copolymerization of PS-b-PMMA and PS-b-P2VP was carried out at -78 ℃. A module-type reactor system was constructed under an inert atmosphere that could monitor the temperature and torque during polymerization. Monomers for the second block were cooled and maintained at approximately -30 ℃ to control the exothermic reaction temperatures while being added to the reactor. The exothermic temperature rise could be minimized (ΔTRMAX ≤ +11 ℃) by addition of the pre-cooled monomer. In chapter five, Living anionic polymerizations of PS-b-PMMA in tetrahydrofuran (THF) were conducted in a plug flow reactor system with a static mixer. Polymers [PS (Mn: 120 x 10^3 g•mol^-1, Mw/Mn: 1.08), PMMA (Mn: 28 x 10^3 g•mol^-1, Mw/Mn: 1.09), P2VP (Mn: 53 x 10^3 g•mol^-1, Mw/Mn: 1.08), and PS-b-PMMA (Mn: 117 x 10^3 g•mol^-1, Mw/Mn: 1.12)] with a precisely controlled high molecular weight were obtained using a diphenyl hexyl lithium initiator in a plug flow reactor system. PS-b-PMMA and PMMA and P2VP were obtained in the presence of LiCl using the plug flow reactor. The molecular weight distribution, which was related to the mixing efficiency of the static mixer, decreased with increasing flow rate. Additionally, the molecular weight of the polymers could be adjusted by varying the flow rates. In chapter six, Using a plug flow reactor system for anionic functionalization and controlled batch reactor system for cationic ring opening polymerization, poly(glycidyl azide-b-styrene) block copolymer was synthesized. For the purpose, first, anionic polymerization of styrene was carried at -25℃ followed by anionic functionalization of polystyrene with epibromohydrin at -78℃. And Epichlorohydrin (ECH) was polymerized by using BF₃-tripropylene glycol (TPG) complex via Active monomer mechanism. After ECH polymerization was complete, ω-epoxy terminated PS (EpPS) was introduced to the PECH solution in presence of BF₃. The resulting polymer had bimodal distribution when the mole ratio of [EpPS]/[TPG] was more than 0.5 due to the PS-PS coupling reaction. Poly(glycidyl azide-b-styrene) (GAP-PS) was obtained by azidation reaction of PECH-PS with sodium azide. Thermal behavior of the PECH-PS block copolymers and GAP-PS block copolymer were also investigated. The thermals analysis showed that PECH was compatible with PS. However, after azidation reaction of PECH-PS, the compatibility of GAP with PS decreased.; The aim of this research is to development of controlled ionic polymerization system for synthesis of GAP based block copolymer with various specifications and consideration of industrial applicability. In chapter two, cationic ring opening polymerization of epichlorohydrin (PECH) produced under various reaction conditions (set temperature: -10-40 ℃, [C]/[I] ratio: 0.1-1, monomer feed rate: 1-4 mL•min^-1) was investigated. In addition, a correlation between the exothermic reaction temperature and the performance of the PECH was obtained by utilizing a reaction temperature monitoring system, GPC, ¹H-NMR, and FTIR. During the polymerization, an induction period which affects the molecular weight distribution was observed below 10 ℃. At lower temperatures and lower [C]/[I] ratios, a higher induction period was observed. The monomer feed rate did not affect the induction period but it highly affected the molecular weight distribution when the induction period occurred. The total molecular weight of PECH increased with decreasing set temperature even though the amount of low molecular weight cyclic oligomer increased. In chapter three, the effect of initiator diol- BF₃ complex solubility on an induction period was investigated for BF₃ catalyzed cationic ring opening polymerization of epichlorohydrin at various [BF₃]/[initiator diol] ([C]/[I]) ratios, using on-line temperature and torque monitoring systems. Other factors influencing the induction period (reaction temperature: -5 – 30 ℃, [C]/[I] ratio, and monomer feed rate: 9.2 x 10^-3 – 27.6 x 10^-3 mol•min^-1) were also investigated in order to optimize the polymerization condition in the presence of the diethylene glycol (DEG)-BF₃ complex. A 5-L, triple-glass jacket reactor was customized for the monitoring system. 1,4 Butanediol (BD) and diethylene glycol (DEG) were used for the initiator diol. In the presence of the BD-BF₃ complex, which is insoluble in methylene chloride solvent (MC), an uncontrollable and highly exothermic reaction occurred shortly after the long induction period. There was an induction period with the DEG initiator diol as well, but the exothermic reaction which followed was much more controlled, and the resulting polymers showed relatively narrow polydispersities (1.31 – 1.34) using DEG initiator diol, which is soluble in MC. The longer induction period, which was highly affected by the solvation effect of the reaction media appeared at lower reaction temperature and lower [C]/[I] ratio. In chapter four, anionic polymerization of styrene, methyl methacrylate and 2-vinyl pyridine using 1 L scale module type batch reactor with consideration of industrial applicability was introduced. Poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and poly(styrene-b-2-vinyl pyridine) (PS-b-P2VP) block copolymers with narrow molecular weight distributions (1.05 ≤ Mw/Mn ≤ 1.17) were achieved via a pre-cooled monomer addition method using a diphenyl hexyl lithium initiator in tetrahydrofuran under sequential isothermal conditions. The styrene block was polymerized at -25 ℃ and -15 ℃, and the second block copolymerization of PS-b-PMMA and PS-b-P2VP was carried out at -78 ℃. A module-type reactor system was constructed under an inert atmosphere that could monitor the temperature and torque during polymerization. Monomers for the second block were cooled and maintained at approximately -30 ℃ to control the exothermic reaction temperatures while being added to the reactor. The exothermic temperature rise could be minimized (ΔTRMAX ≤ +11 ℃) by addition of the pre-cooled monomer. In chapter five, Living anionic polymerizations of PS-b-PMMA in tetrahydrofuran (THF) were conducted in a plug flow reactor system with a static mixer. Polymers [PS (Mn: 120 x 10^3 g•mol^-1, Mw/Mn: 1.08), PMMA (Mn: 28 x 10^3 g•mol^-1, Mw/Mn: 1.09), P2VP (Mn: 53 x 10^3 g•mol^-1, Mw/Mn: 1.08), and PS-b-PMMA (Mn: 117 x 10^3 g•mol^-1, Mw/Mn: 1.12)] with a precisely controlled high molecular weight were obtained using a diphenyl hexyl lithium initiator in a plug flow reactor system. PS-b-PMMA and PMMA and P2VP were obtained in the presence of LiCl using the plug flow reactor. The molecular weight distribution, which was related to the mixing efficiency of the static mixer, decreased with increasing flow rate. Additionally, the molecular weight of the polymers could be adjusted by varying the flow rates. In chapter six, Using a plug flow reactor system for anionic functionalization and controlled batch reactor system for cationic ring opening polymerization, poly(glycidyl azide-b-styrene) block copolymer was synthesized. For the purpose, first, anionic polymerization of styrene was carried at -25℃ followed by anionic functionalization of polystyrene with epibromohydrin at -78℃. And Epichlorohydrin (ECH) was polymerized by using BF₃-tripropylene glycol (TPG) complex via Active monomer mechanism. After ECH polymerization was complete, ω-epoxy terminated PS (EpPS) was introduced to the PECH solution in presence of BF₃. The resulting polymer had bimodal distribution when the mole ratio of [EpPS]/[TPG] was more than 0.5 due to the PS-PS coupling reaction. Poly(glycidyl azide-b-styrene) (GAP-PS) was obtained by azidation reaction of PECH-PS with sodium azide. Thermal behavior of the PECH-PS block copolymers and GAP-PS block copolymer were also investigated. The thermals analysis showed that PECH was compatible with PS. However, after azidation reaction of PECH-PS, the compatibility of GAP with PS decreased.