稀土配位催化N-取代马来酰亚胺均聚及其共聚合研究

【作者】 卢彦兵；

【导师】 孙维林； 沈之荃；

【作者基本信息】 浙江大学 ， 高分子化学与物理， 2003， 博士

【摘要】 N-取代马来酰亚胺是一种比较优良的功能单体，由于分子内酰亚胺五元环的存在，可以与其它单体进行共聚合以提高聚合物的耐热性能。本论文首次较系统地用稀土配位催化剂研究了N-苯基马来酰亚胺（NPMI）、N-十八烷基马来酰亚胺（NODMI）配位催化均聚合以及NPMI与苯乙烯（St）、环氧丙烷（PO）、环氧氯丙烷（ECH）、甲基丙烯酸甲酯（MMA）和环己烯（CHE）的共聚合反应，取得了如下结果： 研究了二元稀土配位催化剂La(P₅₀₇)₃-Al（i-Bu）₃体系催化NPMI均聚合反应。得到N-苯基马来酰亚胺均聚合的适宜聚合反应条件为：[La(P₅₀₇)₃]=10^-2mol·L^-1；[Al（i-Bu）₃]=8.0×10^-2mol·L^-1；[NPMI]=5.0×10^-1mol·L^-1；60℃；6h。聚合物的核磁和红外分析表明，聚合反应是通过打开单体内的碳碳双键的方式进行的。PNPMI的初始热分解温度为390℃，最大热分解温度为420℃。配位聚合反应机理研究表明：单体先与催化剂活性中心进行配位，然后打开碳碳双键进行聚合反应。 研究了N-十八烷基马来酰亚胺（NODMI）单体的合成及其聚合。首次采用La(P₅₀₇)₃·Al（i-Bu）₃体系研究了NODMI的均聚合反应，得到的适宜聚合反应条件为：[La(P₅₀₇)₃]=10^-2mol·L^-1；[Al（i-Bu）₃]=8.0×10^-2mol·L^-1；[NODMI]=5.0×10^-1mol·L^-1；60℃；6h。PNODMI初始分解温度为360℃，最大分解温度为441℃。 研究了Nd（naph）₃-AlEt₃催化体系催化NPMI—St的共聚合反应，得到二元共聚合反应的适宜条件为：Nd（naph）₃=5.0×10^-3mol／L；[NPMI]=[St]=4.5×10^-1mol／L；Al／Nd=9；50℃；6h。对聚合物的结构分析表明，P（NPMI-St）为NPMI与St单元交替排列的交替聚合物；P（NPMI-St）具有良好的热性能，在350℃以下比较稳定，没有分解，初始热分解温度为380℃，最大热分解温度为430℃。测定了两种单体的竞聚率：r_NPMI=0.062，r_（st）=0.015。结合核磁分析，初步提出了NPMI—St形成的电子转移络合物在二元稀土催化剂Nd（naph）₃-AlEt₃作用下的配位共聚合机理：催化剂活性中心先与NPMI配位，打开碳碳双键后再继续与电子转移络合物进行配位和链增长反应。 La（naph）₃—AlEt₃体系用于催化MAn、St和NPMI的三元共聚合反应，得到三元共聚合反应的适宜条件为：La（naph）₃=5.0×10^-3mol／L；[NPMI]=[MAn]=2.25×10^-1mol／L；[St]=4.5×10^-1mol／L；Al／Nd=6；50℃；2h。聚合物结构分析浙江大学博士学位论文:稀土配位催化N一取代马来酸亚胺均聚及其共聚合研究表明p（NP呱一St.MA刃）为三种单体单元共存的三元共聚物;p（Np呱一St，M恤）在300℃时热失重仅为2 .7wt%，初始热分解温度为320℃，最大热分解温度为405℃。 采用La（P507）3一Al（i一Bu）:体系研究了NP砚与PO的共聚合反应，共聚合反应的适宜条件为:压aj一10一Zmol.L一‘，LAI住Bu为卜8.oX10一“mol一气〔PO]二{Np呱卜4.oX 10一’mol.L一，，60℃，6h;对p倒P呱，PO)的核磁、红外等分析表明，得到的聚合物为二元共聚物。p（礴呱一PO）的初始热分解温度为招O℃，最大热分解温度为423℃。测定了La（P 507）3一月（i一Bu）3催化体系下卜甲M」与Po两种单体的竞聚率:r（N PMI）= 1 .441，r（vo）一0.209。对共聚合反应初始阶段的紫外光谱分析表明，在聚合反应开始时，催化剂活性中心先与N甲闷进行配位，打开双键形成增长中心后，NP呱与环氧烷烃竞争与增长中心配位进行链增长反应。由于N’P随的配位能力强于环氧烷烃，得到的共聚物中含有较多的NP碱单体单元。 二元稀土催化剂Nd伊50加一Al（i一Bu）3体系催化N’P随与ECH的共聚合反应，得到该共聚合反应的适宜条件为:困dl一10一“mol.L一伙【Al（i一Bu）3]/困d（Pso7）3卜8;【Ml/困d（Pso7）3]=100;侧P随]二[ECH」，60oC;4h;采用红外、核磁等方法对聚合物进行了有效的表征。p（NP呱一EC玛的热重分析显示聚合物具有良好的耐热性能，初始热分解温度为311℃，由于环氧氯丙烷单体单元的存在，该聚合物具有两个最大热分解温度，分别在341℃和422℃。测定了Nd（P507）3一Al价Bu）3催化体系下碑树与ECH两种单体的竞聚率:r困PM，)二0 .693，r（EeH）一0.005。 初步研究了Nd（P507）3一Al住Bu)3二元稀土催化体系催化砰呱与MMA和砷随与CHE共聚合。测定了催化体系下单体的竞聚率，N甲入n与MMA两种单体的竞聚率为:伽PMI)=l .565，r（MMA）一0.216;N’P随与C甩两种单体的竞聚率:r卿PMD一2·4%，rz（CHE）一0.024·得到的聚合物P仲呱，刚助的初始分解温度为394℃，最大分解温度为425℃，聚合物具有良好的热性能。 以上研究成果表明，稀土配位催化剂是催化N一取代马来酞亚胺进行配位聚合反应的优良催化剂，得到的N一取代马来酞亚胺均聚物和共聚物是一类具有耐热性能的高分子。更多还原

【Abstract】 N-substituted maleimides are excellent functional monomers which can improve the thermal properties of polymers when they are copolymerized with common monomers because of the five-number imide rings in the molecule. The homopolymerizations of N-phenylmaleimide(NPMI), N-Octadecylmaleimide (NODMI) and the copolymerizations of NPMI with styrene(St), propylene oxide(PO), epichlorohydrin (ECH), methyl methacrylate(MMA) and cyclohexene (CHE) were investigated using rare earth coordination catalysts for the first time.Homopolymerization of NPMI was studied by binary rare earth coordination catalyst: La(P507)3-Al(i-Bu)3 system and the suitable polymerization conditions obtained were as follows: [La(P507)3]=10-2 molL-1, [Al(i-Bu)3]=8.0 x l0-2 mol L-1 , [NPMI] =5.0xl0-1 mol L-1, 60℃, 6h. NMR and FT-IR characterizations of the polymer indicated that polymerization of NPMI was proceeded via the opening the double carbon-carbon bond in the NPMI molecules. The polymer PNPMI possessed good thermal stability with initial thermal decomposition temperature at 390℃ and maximum thermal decomposition temperature 420℃ Coordination polymerization mechanism was proposed: the monomer molecule coordinates with the active center in the catalyst, opening the double bond to proceed the polymerization.Synthesis of NODMI was studied and the polymerization of NODMI by La(P507)3- Al(i-Bu)3 system was investigated for the first time. The optimum conditions for the polymerization were: [La(P507)3]=10-2 mol L-1, [Al(i-Bu)3]=8.0 x 10-2 mol L-1 , [NODMI] =5.0x10-1 molL-1, 60℃, 6h. Results showed that the polymer PNODMI had high molecular weight. The initial thermal decomposition temperature of the polymer was 360℃ and maximum thermal decomposition temperature 441℃.Copolymerization of NPMI with St by Nd(naph)3- AlEt3 system was studied. The preferred conditions were: Nd(naph)3=5.0xl0-3 mol/L, [NPMI]=[St] =4.5x 10-1 mol/L, Al/Nd=9, 50℃, 6h. Characterization of the copolymer P(NPMI-St) showed that P(NPMI-St) has an alternating structure. The obtained reactivity ratios of the monomers were r(NpMI)=0.06185, r(St)=0.01507. Coordinationcopolymerization mechanism with the participation of the charge transfer complex between NPMI and St was suggested. The P(NPM3-St) showed good thermal stability with no obvious decomposition under 350℃. The initial thermal decomposition temperature was 380℃ and maximum thermal decomposition temperature 430℃Terpolymerization of NPMI, St and MAn was also investigated by La(naph)3 -AlEt3 system. The suitable polymerization conditions were La(naph)3=5.0x10-3 mol/L, [NPMI]= [MAn]=2.25 x l0-1 mol/L, [St]= 4.5 x 10-1 mol/L, Al/Nd=6; 50℃, 2h, Characterization of P(NPMI-St-MAn) verified that the polymer obtained were the terpolymer of the three monomers. The P(NPMI-St-MAn) had good stability with weight loss only 2.7wt% at 300℃. The initial thermal decomposition temperature of P(NPMI-St-MAn) was 320 ℃ and the maximum thermal decomposition temperature 405℃.Copolymerization of NPMI with PO catalyzed by rare earth coordination catalyst La(P507)3-Al(i-Bu)3 system was investigated. The optimal conditions obtained were [La]-10-2 mol L-2, [Al(i-Bu)3]=8.0 X 10-2 mol-L-1, [PO]=[NPMI] =4.0X 10-1 mol L-1, 60℃, 6 h. The reactivity ratios of the two monomers in the La(P507)3-Al(i-Bu)3 system were r(NPMi)= 1.441 and r(po)=0.209. The UV-vis spectrum of the polymerization mixture at the initial stage showed that the active center had a stronger ability to coordinate with NPMI than that with PO, resulting in more NPMI units in the copolymer.Using Nd(P507)3-Al(i-Bu)3 binary catalyst system, copolymerization of NPMI with ECH was studied. The preferred conditions were: [Nd]=10-2mql L-1,. [Al(i-Bu)3]/[Nd(P507)3]=8, [M]/ [Nd(P507)3]=100, [NPMI]=[ECH], 60℃, 4h,, The copolymers were characterized by NMR, FT-IR and TGA. TGA results showed that P(NPMI-ECH) possessed excellent thermal stability with an initial thermal decomposition temperature at 311 ℃. Because of the ECH units in the copolymer, P(NPMI-ECH) had two更多还原