聚硫醚醚酮(砜)芳香环状低聚物的合成与自由基开环聚合

在“拟高稀释”条件下,通过亲核缩聚反应高产率地合成了含硫醚键的芳香醚环状低聚物.应用核磁、GPC和激光质谱(MALDI-TOFMS)等手段对环状低聚物的结构进行了确认,并研究了环状低聚物的组分分布.聚硫醚醚酮环状低聚物在硫醚自由基的引发下进行快速熔融聚合,得到热稳定性很好的高分子量线性聚合物.     

芳香酯环状低聚物的合成、结构及开环聚合——制备高性能树脂的一条新途径

在“拟高稀释”(pseudo-high-dilution)的模拟条件下,邻苯二甲酰氯和一系列双酚界面缩聚反应选择性地生成了一系列芳香酯环状二聚体.单晶X-射线晶体结构分析其中两个大环二聚体酯表明,这些环状二聚体是没有张力或张力很小的大环结构,选择性地生成环状二聚体是由两种反应单体存在有利于环化的构型决定的.这些没有张力的大环芳香酯低聚物在阴离于催化剂条件下快速地熔融聚合,得到高分子量的线性芳香聚酯.     

环状芳香低聚物的合成及应用研究进展

综述了近年来环状芳香低聚物的合成及应用研究发展状况,对其合成方法和应用情况进行了综述和分析,并对今后的研究发展进行了预测。     

亲电缩聚反应合成芳香环状低聚醚酮砜及其开环聚合

"假高稀"条件下,以邻苯二酰氯为酰基化试剂,Lewis碱NMP存在下,通过亲电缩聚反应高产率地合成了2种芳香环状聚醚酮砜低聚物,利用MALDI-TOF-MS,NMR,GPC,FTIR,DSC等手段对环状结构进行了精确的表征.在负离子引发剂联苯双酚钾存在下,环状低聚物3a进行熔融开环聚合,得到了高分子量的线型聚合物,Tg为221.8℃.利用流变仪监测了环状低聚物3a开环聚合过程中的流变行为,结果表明,开环聚合初期的引发阶段,熔融体的黏度低于10Pa.s,随着时间的延长,黏度快速增长,而且低黏度的引发阶段随着引发剂浓度的增加而变短.     

环碳酸酯开环聚合物制备、性能和应用研究进展

综述了近年来环碳酸酯开环均聚与共聚产物的制备、性能与应用研究进展     

三亚甲基环碳酸酯及2,2-二甲基三亚甲基环碳酸酯开环均聚合*

生物降解聚合物聚三亚甲基环碳酸酯（PTMC）及聚2,2-二甲基三亚甲基环碳酸酯（PDTC）在药物控释载体及其它生物医学技术领域有着良好的应用前景。与脂肪族聚酯不同,PTMC、PDTC降解时,不会产生有害的酸性化合物。PTMC、PDTC主要由三亚甲基环碳酸酯（TMC）及2,2-二甲基三亚甲基环碳酸酯（DTC）开环均聚合制备。本文总结了催化TMC、DTC开环均聚合的不同催化剂及其聚合机理,综述了近年来国内外在TMC、DTC均聚合催化剂开发上的研究进展,并对生物相容性催化剂如稀土催化剂、Ca、Mg、Zn、Fe催化剂以及酶催化剂催化TMC、DTC开环聚合的优缺点进行了比较。     

大环碳酸酯的Novozym-435酶促开环聚合

研究了14元环的碳酸丁二酯二聚体在固定化脂肪酶Novozym-435催化下的开环聚合反应制备聚碳酸丁二酯.聚合在常压,75℃的甲苯溶液中进行,反应条件温和.详细探讨了反应条件诸如单体浓度,酶浓度对于聚合的影响.结果显示Novozym-435具有与异辛酸亚锡可比拟的高催化活性,同时可以回收重复使用.聚合动力学研究表明碳酸丁二酯的酶促甲苯溶液开环聚合和环状内酯的酶促甲苯溶液聚合有所不同,没有表现出活性聚合的特征.     

Lewis酸碱对催化的可再生环状缩醛酯单体的开环聚合研究

从生物质原料3,4-二氢吡喃出发,合成了可再生环状缩醛酯单体(H-AE),从结构上看,该单体在γ-丁内酯中引入了缩醛单元,在开环聚合过程中,通过释放甲醛分子有希望在温和条件下得到聚(γ-丁内酯).选用合适的Lewis酸碱对催化剂,基本抑制了聚合过程中的链回咬副反应,实现了单体的可控聚合.详细研究了催化剂的酸/碱性强度及其位阻大小对于合成的聚合物的组成和比例的影响,通过设计和优化催化剂的结构,实现了聚合物中聚丁内酯单元和聚缩醛酯单元比例的调控.对所得聚合物进行了1H-NMR、13C-NMR及扩散排序核磁共振(DOSY)表征,结合聚合过程的核磁与SEC监测,证实所得聚合物为丁内酯与缩醛酯的无规共聚物.根据实验数据和表征结果,推测聚合遵循Lewis酸碱对调控的阴离子开环聚合机理,酸碱催化剂共同稳定活性链末端,实现了亲核进攻和甲醛的脱除.     

苯硫醚环状低聚物的合成与初步聚合研究

以硫化钠和对二氯苯为原料,加入锂盐复合助剂,在六甲基磷酰三胺溶剂中,常压下合成了苯硫醚环状低聚物（CPS）,研究了助剂用量、单体浓度和反应时间等条件的影响,并对合成的产物进行了初步表征和热聚合试验。结果表明：采用助剂后,可以在提高反应物浓度、缩短反应时间的同时,得到较高的合成产率;合成产物的红外、紫外光谱与文献一致;CPS的热聚合产率高。     

环状对苯二甲酸丁二酯低聚物CBT的研究进展

环状对苯二甲酸丁二酯低聚物CBT作为目前唯一工业化的芳香基环状低聚物,以其超低熔体黏度、边聚合边结晶特性、开环聚合无反应热、无小分子副产物释放等优点受到工业界和学术界的共同关注,尤其是在连续纤维增强复合材料领域得到了广泛应用。本文从CBT的制备方法与聚合机理入手,系统梳理了CBT聚合过程的流变行为、聚合与结晶的关系、结晶形貌、复合材料的制备及应用、基体树脂的脆性机理、纯树脂及复合材料体系增韧方法、边聚合边结晶过程等方面的研究进展,并就存在的问题进行了展望,对CBT及其它芳香基环状低聚酯研究及应用具有指导意义。     

TAILORING POLYMERS WITH NOVEL STRUCTURES VIA RING OPENING METATHESIS POLYMERIZATION

ThisProjectwassupportedby"NationalNaturalScienceFoundationofChina(projectapprovalnumber29474160)"and"FOundationofStateKeyLaboratoryofFunctionalPolymericMaterialsforAdsorptionandSeparation,NankaiUniversity(kf035)".ThisisalsoaninvitedlecturegivenattheChemistryDepartmentofSophiaUniversity,Japan,onJan.14,1998.ReceivedMay5,1998##D1NTRODUCTIONInrecentyearssomedramaticadvancesinthefieldofROMPhaveattractedgreatinterestandattentionofscientistsengagedinthedesignandtailoringofmolecularstr…     

活性开环歧化合法合成带羧酸酯基功能高分子

由石油化工C5馏分提取得到的粗产品双环戊二烯(DCPD,83.9%)经精馏制成高纯度双环戊二烯(98.9%),解聚后制成环戊二烯(CPD).以CPD、丙烯酸叔丁酯(tBA)为原料经Diels-Alder反应合成得到了一种带叔丁氧羰基的降冰片烯衍生物-2-叔丁氧羰基-5-降冰片烯(BOCN).以钌卡宾络合物RuCl2(PCy3)2(=CHPh)为引发剂进行所合成降冰片烯基单体BOCN的活性开环歧化聚合(ROMP)反应,合成得到一种具有受控分子量及窄分子量分布的带羧酸酯基的反应性高分子.     

双环戊二烯开环歧化聚合反应催化体系的配位体效应研究

用WCl6－Et2AlCl催化体系进行双环戊二烯的开环歧化聚合反应，考察了催化体系的配体效应。实验结果表明在催化体系中添加位阻酚—2．6-二叔丁基-对甲苯酚（DTBC）能明显提高聚合反应的转化率和合成聚合物的机械性能（如冲击强度、拉伸强度等）。利用位阻高分子酚──线形酚醛树脂（LPF）作为配体也得到类似的结果。     

可修饰的内酯，α-氯甲基-α-甲基-β-丙内酯的合成和聚合

可修饰的内酯，α－氯甲基－α－甲基－β－丙内酯的合成和聚合＊王明霞李子臣贺晓晖杨丽＊＊李福绵（北京大学化学系北京１００８７１）关键词α－氯甲基－α－甲基－β－丙内酯，开环聚合＊１９９５－０２－２０收稿；１９９６－０３－１２修回：自然科学基金课题；＊＊...     

FREE RADICAL RING OPENING POLYMERIZATION OF CYCLIC ACRYLATES

Cyclic acrylates, 2,2- dimethyl-5-methylene-1 , 3-dioxolan-4 -one and 2- phenyl-5-methylene-1,3-dioxolan-4-one, were synthesized successfully. The monomers were characterized by ~1H NMR, ~(13)C NMR, IR and elemental analysis or HRMS. Polymerization of the monomers were carried out at 120℃with di-t-butylperoxide as initiator. The polymers were studied by ~1H NMR, ~(13)C NMR, UV and hydrolysis. The molecular weights of the resulting polymers were estimated by viscosity measurement and the extent of ring opening was estimated also by ~1H NMR and hydrolysis of the polymers and further confirmed by UV spectra.     

载体化络合催化开环歧化聚合合成梳形接枝共聚物研究

由环戊二烯（CPD）及烯丙基氯（AC）经聚合物支载三氟化硼催化的Diels-Alder反应合成了5-氯甲基-2-降冰片烯（NB-CH2Cl),锂代后用以引发甲基丙烯酸甲酯（MMA）及苯乙烯（S）的活性阴离子聚合,合成了带聚合物取代基的降冰片烯大分子单体NB-PMMA及NB-PS。在聚合物支载钌卡宾络合物催化作用下进行所合成大分子单体的开环歧化聚合反应（ROMP）,合成了二种接枝于开环歧化聚降冰片烯（PNB）主链的梳形接技共聚物PNB-g-PMMA及PNB-g-PS。实验结果表明所研制聚合物支载硼、钌络合物催化性能明显优于对应非支载活性种。     

SYNTHESIS OF A COMB GRAFT COPOLYMER VIA RING OPENING METATHESIS POLYMERIZATION CATALYZED BY SUPPORTED RHUTHENIUM CARBENE COMPLEX

Comb graft copolymers (CGC), a special kind of the hyper-branched polymer series, have unique and excellent properties [1,2]. Synthesizing CGC via ring opening metathesis polymerization (ROMP) of cycloolefinyl macromonomer catalyzed (initiated) by the molybdenum carbene complex (Schrock complex) is a newly-developed method [3,4]. Though showing excellent catalytic behavior the complex has the disadvantage of highly moisture and oxygen sensitive and is hence operation-inconvenient. We repor…     

SYNTHESIS AND FREE RADICAL POLYMERIZATION OF 2-OXO-3-METHYLEN E-5-PHENYL-1,4-DIOXAN

The novel cyclic monomer, 2-oxo-3-methylene-5-phenyl-1,4-dioxan, was synthesized by a set of reactions. Several intermediates were prepared and characterized in order to determine the monomer structure. The presence of chiral centers in the intermediates and resulting monomer makes it complicated to separate , purify and characterize them. It is a very reactive monomer which will polymerize even at room temperature if expose to moisture and air. This monomer can undergo essentially quantitative flee radical ring opening polymerization. The driving force for ring opening is the formation of new carbonyl group and benzylic radical. The monomer and polymer structure were established by IR, ~1H NMR, ~(13)C NMR and elemental analysis or high resolution mass spectrum. The molecular weight of the resulting polymer was estimated by viscosity determination.     

SYNTHESIS OF A COMB GRAFT COPOLYMER VIA RING OPENING METATHESIS POLYMERIZATION CATALYZED BY SUPPORTED RHUTHENIUM CARBENE COMPLEX

5－Chloromethyl-2-norbornene was synthesized via Diels-alder reaction of cyclopentadiene and allyl chloride using a polymer supported boron trifluoride as the catalyst,and was then lithiated and used to initiate a livcing anionic polymerization of styrene to prepare a macromonome,5-polystryl-2-norbornene NB-PS,Comb graft copolymer PNB-g-PS was synthesized via ring opening metathesis polymerization of the macromonomer under the catalysis of ruthenium carbene complex RuCl2(PPh3)2(=CCHtBu)and its polymer supported correspondent.Experimetal results showed that the behavior of both the supported boron and supported ruthenium catalysts are superior to their unsupported counterparts.The possible promotion mechanism of the tailor-made supports is discussed.     

SYNTHESIS AND ANIONIC POLYMERIZATION OF 2-METHYL-2-METHOXY CARBONYL-5-METHYLENE-1, 3-DIOXOLAN-4-ONE

A new cyclic monomer, 2-methyl-2-methocycarbonyl-5-methylene 1,3-dioxlan-4-one,wassynthesized successfully. The monomer and intermediate were characterized by ~1H NMR,~(13)C NMR, INEPT (Intensive Nuclei Enhanced by Polarization Transfer) technique, IR andelemental analysis. Anionic polymerization of the monomer was carried out in anhydrous THF at.70℃, and 9-fluorenyllithium was used as initiator. The polymer strucure was determined byIR, NMR and elemental analysis. Molecular weight of the polymer was estimated by viscositymeasurement in DMSO at 30℃.