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1.
Some new poly(amide-imide) siloxane copolymers have been synthesized by solution polycondensation of some aromatic diamines with siloxanic diacids having preformed imide rings. Two polycondensation techniques were used: polycondensation of aromatic diamines with diacid chlorides and direct polycondensation of aromatic diamines with diacids in the presence of organic phosphites, following the Yamazaki-Higashi phosphorylation technique. In all cases the reactions were carried out using equimolecular amounts of the two monomers, in polar aprotic solvents and inert atmosphere.The obtained compounds were characterized by elemental C, H and Si analysis, solubility tests, IR and 1H-NMR spectrometry. Thermogravimetric curves were also recorded. All data agree with the proposed structures. 相似文献
2.
Kenji Hanabusa Xuanjing Ye Akio Kurose Hirofusa Shirai Tadao Hayakawa Nobumasa Hojo 《Journal of polymer science. Part A, Polymer chemistry》1989,27(12):4191-4204
Amphiphilic active 4-dodecanoyl-2-nitrophenyl esters of dipeptide containing β-alanine ( 1 – 5 ) were prepared and their polycondensation was studied in detail. The critical micelle concentrations of the active esters 1 – 5 were determined in water by the dye method and the apparent mean aggregation number of reversed micelles formed by model compound 6 was determined by the osmotic method. The results of polycondensation can be explained by assuming that aggregations such as micelle and reversed micelle play an important role in polycondensation. The obtained new poly(dipeptide)s were examined by IR, 1H NMR, x-ray diffraction, and circular dichroism spectra. 相似文献
3.
Cristoni S Armelao L Gross S Tondello E Traldi P 《Rapid communications in mass spectrometry : RCM》2000,14(8):662-668
The polycondensation of Ti(O-i-C3H7)4 (1) and Ti(O-n-C4H9)4 (2), precursors widely employed in sol-gel processes, has been investigated by electrospray ionization mass spectrometry. By analysis of 10(-6) M methanol solutions of compounds 1 and 2, the same ionic species are detected, proving that the first step in the polycondensation reaction is the i-propyl (or n-butyl) alcohol-methanol complete exchange. This reaction leads to the Ti(OCH3)4 (3) species, representing the synthon of the polycondensation. Various oligomers of 3 have been detected and characterized by MS/MS experiments, and the related mechanisms have been discussed. A minor oligomeric series due to hydroxyl-containing polycondensation products has also been characterized. 相似文献
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5.
Thering-openingpolymerization(ROP)reactionplaysanimportantroIeinproductionofhigh-performancethermoplastics'.ThecyclicoligomersofferauniquecombinationoflowmeltviscosityandthecapabilityofachievingveryhighmolecuIarweightinashortreactiontimewithoutthereleaseofvolatilebyproductsandROPhasbeenanactivesubjectofindustrialandacademicresearch.TheROPsofmanycyclicoligomershavebeenachievedviaanionicpolymerizationinthepresenceofthenucleophilicinitiatorsuchascaesiumfluorideandalkaliphenoxides',butusingthe… 相似文献
6.
Abstract The aliphatic polyesters are normally synthesized by ester interchange reactions or direct esterification of hydroxyacids or diacid/diol combinations. Biotransformation, utilizing the enzymes as catalysts, was accepted as an alternative route for the synthesis of aliphatic polyesters and offers various advantages compared with the conventional, metal-catalyzed polymerization reactions. Previous studies indicated that lipase-catalyzed polycondensation reactions between diols and diacids occurred preferentially at primary hydroxyl groups of diols, when diols contained both primary and secondary hydroxyl groups. In this work, we investigated lipase-catalyzed polycondensation of diacids and secondary hydroxyl group–containing diols, and successfully synthesized polyesters by polycondensation with secondary hydroxyl groups as well as primary hydroxyl groups. Various diols, glycerol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, and 2,4-pentanediol were tested for the polycondensation. The polymerization was achieved by heating a mixture of lipase B, sebacic acid, and the diols in anhydrous toluene at 100 °C for 72 h. The resulting polymers were characterized by 1H and 13C NMR spectroscopy, Fourier transform–infrared spectroscopy, thermogravimetric analysis, and gel permeation chromatography. 相似文献
7.
A new pyridine-based diacid containing ether and imide units was synthesized via reaction of 5-amino-1-naphthol with 2,6-dichloropyridine in the presence of potassium carbonate in N-methyl-2-pyrrolidone (NMP), and subsequent reaction of the obtained diamine with 2 mol of trimellitic anhydride. A series of poly(ether imide ester)s was synthesized by the polycondensation reactions of the prepared diacid with different diols via high temperature solution polycondensation reaction method. All the products were fully characterized by common spectroscopic methods. The polymers were examined by elemental analysis, IR and 1H NMR spectra, inherent viscosity, X-ray diffraction, DSC, TGA and DMTA and their properties were studied. Polymers showed high thermal stability and good solubility in polar aprotic solvents. The Structure-property relations of the polymers were also studied. 相似文献
8.
Saloua Chelli Mustapha Majdoub Salah Aeiyach Mohamed Jouini 《Journal of polymer science. Part A, Polymer chemistry》2009,47(17):4391-4399
A polyrotaxane in which β‐cyclodextrins (β‐CDs) are threaded onto a polyether chain was prepared by polycondensation of a β‐CD/bisphenol A (BPA) inclusion complex with aromatic dihalides. Two dihalides, with and without a side chain, were used. This polycondensation results in a polyrotaxane (or pseudopolyrotaxane for polymers without stoppers) with a 1:1 threading ratio when the side chain is present and 2:3 when there is none. The long side chain prevents dethreading of the macrocycles. The best yield and a good threading ratio were obtained when the polycondensation was performed by liquid?solid phase transfer catalysis without solvent (L/S PTC) using 2,5‐bi(iodomethyl)‐4‐methoxy‐(1‐octyloxy)benzene as dihalide. The 1H NMR and FTIR spectra show that the products consist of β‐CD and polyether. The 2D NOESY NMR spectrum shows that the polyether chains are included in the β‐CD cavity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4391–4399, 2009 相似文献
9.
James Dibattista Brian M. Schmidt Anne Buyle Padias H. K. Hall 《Journal of polymer science. Part A, Polymer chemistry》2002,40(1):43-54
The effect of alkyl groups on the polycondensation of aromatic diamines and quinones to form poly(quinone imine)s was investigated. Models were synthesized under standard conditions: 1 equiv of quinone was reacted with 2 equiv of aniline in the presence of titanium tetrachloride and 1,4‐diazabicyclo[2.2.2]octane. Only modest yields of diimines were obtained when alkyl substituents were introduced. Likewise, alkyl substituents were harmful in the polycondensation of both anthraquinones and benzoquinones with aromatic diamines. As for fluorine substituents, model reactions with either 1,5‐difluoroanthraquinone or 1,4‐difluoroanthraquinone with aniline proceeded in high yields. These model compounds for aromatic poly(quinone imine)s were characterized with 1H NMR spectroscopy, 19F NMR spectroscopy, variable‐temperature 1H NMR spectroscopy, and X‐ray crystal structure determination. Polymers of the difluoroanthraquinones with aromatic diamines were obtained in high yields, although not in high molecular weights, and no stereocontrol was found. Both p‐benzoquinones and anthraquinones were used as monomers in these polymerizations, and a fundamental difference in reactivity was observed. With the former, the polymerization behaved as a classical polycondensation and demanded exact reagent equivalence. With the anthraquinones, however, the polymerization proceeded by a condensation chain polymerization and was much more forgiving. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 43–54, 2002 相似文献
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Zangrando R Armelao L Bottaro G Gross S Seraglia R Tondello E Traldi P 《Rapid communications in mass spectrometry : RCM》2006,20(18):2681-2688
The hydrolysis and polycondensation reactions of Al(OBu(s))3 have been studied by laser desorption/ionization (LDI), performed on the solid samples originating from different aluminum alkoxide solutions, prepared using the usual operating conditions employed in the sol-gel synthesis of Al2O3-based materials. CHCl3, CH3OH and CH3OH/H2O mixture were used as solvents. In the latter case different H2O/Al(OBu(s))3 molar ratios were adopted, i.e. 1:1, 1:2, and 1:4. The obtained hydrolysis and polycondensation species consist of polynuclear species containing < or =12 aluminum atoms. In the CHCl3 solutions, the formation of the observed hydrolysis products has been ascribed to the reaction with water present in the atmosphere during the LDI sample preparation and/or present at trace level in the solvent. When methanol is used as a solvent, extensive methanolysis reactions take place, thus originating oligomers with CH3O and OH substituents. The kinetics of formation of the various polynuclear species are dependent on the reaction environment and the reaction is faster in the presence of methanol. It is worth noticing that, regardless of the hydrolysis process, the polycondensation products can be considered as originating from a common tetrameric core [Al4O4(OBu)2(OH)2] around which different building blocks are condensed to form various oxo-polymeric species. 相似文献
12.
以可再生资源2,5-呋喃二甲酸(FDCA)和1,8-辛二醇(1,8-ODO)为原料,钛酸四丁酯为催化剂,采用直接酯化法制得聚2,5-呋喃二甲酸1,8-辛二酯(1,8-POF)。 考察了原料配比、催化剂用量、酯化温度、缩聚温度及缩聚时间对聚合反应的影响,结果表明,当n(FDCA)∶n(1,8-ODO)=1∶1.2,钛酸四丁酯摩尔分数为0.3%,酯化温度为240 ℃,缩聚温度为260 ℃,缩聚时间为300 min时,缩聚产物的比浓粘度最高(2.1 dL/g),端羧基含量最低(5.8 mol/t)。 与乙二醇相比,采用1,8-辛二醇为单体降低了酸醇的摩尔比,减少了醇的消耗,同时得到了较高分子量的聚合物。 气质联用仪对酯化馏出液和缩聚产物真空抽出物进行了分析,结果表明,酯化馏出液的主要成分是水,并含有少量的1,8-ODO;缩聚产物真空抽出物的组成为环己酮(56%)、顺式-3-辛烯醇(18%)、4-甲基-3-戊烯-2-酮(17%)和4-羟基-4-甲基-2-戊酮(9%)。 相似文献
13.
合成了3种主链含己烷雌酚的生物可降解的聚磷酸酯,结构经IR,^1HNMR和元素分析鉴定,通过水接触角的测定研究了聚合物的亲水-疏水性能,以pH值变化表征了聚合物的体外水解速率。初步的体外实验表明,此类聚磷酸酯具有较好的体外抗艾氏腹水癌活性。 相似文献
14.
Jun-ichi Kadokawa Yuhki Tanaka Yoritake Yamashita Kazuya Yamamoto 《European Polymer Journal》2012,48(3):549-559
Poly(spiropyran)s were synthesized by polycondensation of a bis(indoline) monomer with bis(o-positioned formyl and hydroxy)-substituted aromatic monomers in alcoholic solvents. The structures of the products and their molecular weights were determined by the 1H NMR and GPC measurements, respectively. Furthermore, photoisomerization behaviors of the poly(spiropyran)s were analyzed by the UV–Vis and 1H NMR measurements of their solutions in dichloromethane upon the UV and visible light irradiations. 相似文献
15.
Ivan Gitsov Frederick E. Johnson 《Journal of polymer science. Part A, Polymer chemistry》2008,46(12):4130-4139
Poly(oxyethylene‐H‐phosphonate)s (POE‐H‐Ps), with different poly(oxyethylene) segment lengths, were synthesized via conventional two‐stage polycondensation reaction of dimethyl‐H‐phosphonate and poly(ethylene glycols) (PEGs), with nominal molecular weights of 400, 600, and 1000 Da. The changes in the composition of the reaction mixtures during the polycondensation process were followed by size‐exclusion chromatography (SEC) and NMR. It was found that the three PEG fragments yield reproducibly POE‐H‐Ps with the following molecular weights: ~3000 Da (PEG‐400), ~6000 Da (PEG‐600), and ~10,000 Da (PEG‐1000) as measured by SEC, NMR, and VPO. The hydrolytic behavior of POE‐H‐Ps upon storage and in aqueous media with pH 3, 7.4, and 8 was studied for the first time by a combination of NMR and SEC. It was found that the long‐term stability of the polymers in dry state depends on the length of the PEG fragments and decreased in the following order: POE‐H‐P(PEG‐1000) > POE‐H‐P(PEG‐600) > POE‐H‐P(PEG‐400). The hydrolytic transformation of the polymers in aqueous media is affected mostly by the pH of the solution. The degradation products are PEG fragments containing phosphonate end groups—an important prerequisite for the usage of the POE‐H‐Ps as nontoxic drug delivery vehicles and in vivo precursors for PEGylated prodrugs. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4130–4139, 2008 相似文献
16.
The oligomer of 4-(4-pyridylmethylideneimino)phenol was formed during oxidative polycondensation in aqueous alkaline medium
using oxygen as the oxidant. Optimum conditions of the oxidative polycondensation and the main parameters of the process were
found. The maximum yield of the oligomer was 52.4%. The product was characterized by elemental analysis, FT-IR spectroscopy,
UV-Vis spectroscopy, and 1H NMR spectroscopy. The molecular weight distribution was determined by size exclusion chromatography. Thermogravimetric and
differential thermal analyses were carried out for 4-(4-pyridylmethylideneimino)phenol and its oligomer.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1785–1788, October, 2006. 相似文献
17.
Mitsuru Ueda Amane Mochizuki 《Journal of polymer science. Part A, Polymer chemistry》1985,23(7):1973-1980
The aminolysis of 3-benzoyloxy-1,2-benzisothiazole and N-benzoyl[1,2-benzisothiazol-3(2H)-one] derived from 1,2-benzisothiazol-3-ol was studied in model systems and was found to give good yields of N-substituted benzamides at room temperature. Solution polycondensation of new bisamides, N,N′-isophthaloyldi[1,2-benzisothiazol-3(2H)-one], and N,N′-adipoyldi[1,2-benzisothiazol-3(2H)-one], proceeded slowly to give polyamides with moderate molecular weights. The chloroform–triethylamine · hydrochloride system was the best polycondensation medium compared with some polar aprotic solvents for the formation of higher-molecular-weight polyamides. 相似文献
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19.
聚酯酸酐的合成与表征 总被引:3,自引:0,他引:3
聚酸酐具有优良的表面溶蚀性能,作为药物控释体系材料得到广泛的应用.以对(2 羟基 乙氧基)苯甲酸和对(2 甲基 2羟基 乙氧基)苯甲酸分别与丁二酸酐,顺丁烯二酸酐和丁二酰氯反应得到六个含有酯基的新型二元酸单体,经熔融聚合得到聚酯酸酐.单体和聚合物经IR,1H NMR和元素分析等表征.研究了催化剂对聚合物结构的影响. 相似文献
20.
Smaranda Iliescu Nicoleta Plesu Adriana Popa Lavinia Macarie Gheorghe Ilia 《Comptes Rendus Chimie》2011,14(7-8):647-651
New structures of polymers containing phosphorus in the main chain were prepared by interfacial polycondensation of phenylphosphonic dichloride with 4,4’-(1,3-phenylenediisopropylidene) bisphenol (bisphenol M) using two different methods: method I: gas–liquid interfacial polycondensation without an organic solvent and a catalyst; and method II: solid–liquid interfacial polycondensation using green solvents and without catalyst. The aim of this work was to apply these methodologies as eco-friendly and economical procedures for a green chemistry. The polymers were characterized by gel permeation chromatography (GPC), FT-IR, 1H and 31P-NMR spectroscopy, differential scanning calorimetry (DSC) and thermal analysis. Yields in the range of 88.0–90.0, and inherent viscosities in the range of 2.2–3.2 dl/g were obtained. High molecular weight polymers (57 600–114 400) have been successfully prepared. The polymers are self-extinguishing and begin to lose weight at around 300 °C. The flammability was investigated by measuring limiting oxygen index values (LOI). 相似文献