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1.
The influence of chemical modification of unsaturated polyesters on viscoelastic properties and thermal behavior of styrene copolymers 总被引:1,自引:0,他引:1
Marta Worzakowska 《Journal of Thermal Analysis and Calorimetry》2009,96(1):235-241
The influence of chemical modification of unsaturated polyesters on viscoelastic properties and thermal behavior of styrene
copolymers has been investigated by DMA and TG analyses. Chemical modification of unsaturated polyesters obtained in polycondensation
of cyclohex-4-ene-1,2-dicarboxylic anhydride (THPA), maleic anhydride (MA) and suitable glycol: diethylene glycol (DEG) or
triethylene glycol (TEG) was performed using 38–40% peracetic acid. It allowed to selective and successful oxidation of carbon-carbon
double bonds in unsaturated polyesters giving modified unsaturated polyesters/unsaturated epoxypolyesters/containing both
carbon-carbon double bonds in polyester chain and new functional groups-epoxy groups in cycloaliphatic rings. Both unsaturated
polyesters and unsaturated epoxypolyesters were used as a component of styrene copolymers cured with different hardeners.
It has been demonstrated that the use of modified unsaturated polyesters as a component of styrene copolymers allowed obtaining
more stiffness and more cross-linked network structure compared to styrene copolymers based on unmodified polyesters. The
higher values of storage modulus, glass transition temperatures and better thermal stability for styrene copolymers based
on unsaturated epoxypolyesters were obtained. 相似文献
2.
Daniela Pappalardo Sofia Målberg Anna Finne‐Winstrad Ann‐Christine Albertsson 《Journal of polymer science. Part A, Polymer chemistry》2012,50(4):792-800
Functionalized poly(lactic acid) having sulfur‐protected groups along the chain have been synthesized with the ultimate aim to obtain materials for reversible and degradable self‐assembly systems. The first step in the synthesis was the preparation of hydroxy‐(4‐methyl‐phenylsulfanyl)‐propionic acid and hydroxy‐(tritylsulfanyl)‐propionic acid. These sulfur‐functionalized hydroxy acids were subsequently used as comonomers in the condensation polymerization of lactic acid producing functionalized polyesters with thio‐protected groups along the chain. The ratio of functionalized hydroxyl‐acid in the copolymer was determined by the feed ratio. The polyesters obtained were amorphous and size exclusion chromatography analysis showed a monomodal distribution. When treated with iodine, the polyesters chains bearing the tritylsulfanyl side groups assembled with the formation of S? S bridges and the molecular weight increased accordingly. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
3.
H. Berbalk K. Eichinger und M. S. Nourafza 《Fresenius' Journal of Analytical Chemistry》1979,299(3):208
Ohne Zusammenfassung
Gas-chromatographic analysis of the monohydric alcohol fraction of the hydrolysis products of 1,4- and 1,8-Dichlorotrans-p-menthane
Strukturzuordnung nach Carman u. Deeth [1]. 相似文献
4.
T. Ranganathan C. Ramesh Anil Kumar 《Journal of polymer science. Part A, Polymer chemistry》2004,42(11):2734-2746
A homologous series of main‐chain thermotropic liquid‐crystalline polyesters containing rigid biphenyl mesogen and flexible methylene spacers were synthesized with the AB‐type self‐polycondensation approach. The polyesters were characterized with 1H NMR, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, polarized light optical microscopy, and X‐ray diffraction. These polyesters, containing trimethylene spacers on the acid side and various spacers on the alcohol side of the biphenyl mesogen, showed an odd–even effect in the transition temperatures and mesophase type. The even members showed higher transition temperatures than the odd ones. A normal smectic mesophase was observed for the even members, whereas the odd‐membered counterparts exhibited a tilted smectic mesophase. To study the effect of connectivity, the mesophase characteristics of these polyesters were compared with those of the isomeric AB‐type polyesters without any methylene spacer on the acid side of the biphenyl moiety. The mesophase characteristics were insensitive to whether the mesogen was connected to a carboxyl unit or a methylene unit. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2734–2746, 2004 相似文献
5.
Tae Oan Ahn Muyoung Lee Han Mo Jeong Kilwon Cho 《Journal of Polymer Science.Polymer Physics》1998,36(2):201-212
The phase behavior of blends of tetramethyl bisphenol-A polyarylate (TMPAr) with various linear aliphatic polyesters characterized by the ratio of aliphatic carbons to ester groups in the repeating unit, CH2/COO = 3 ∼ 9, was examined by differential scanning calorimetry and dynamic mechanical analysis. TMPAr/aliphatic polyester blends prepared by solvent casting were found to be miscible when the CH2/COO ratio of aliphatic polyesters was larger than 4 and up to 9. The thermodynamic interaction parameter, B for the miscible blends was determined by the analysis of the depression of the melting point of polyester using the Hoffman-Weeks method. From the analysis of the heat of mixing data using a binary interaction model, it was concluded that strong unfavorable intramolecular interaction exists between the CH2 and COO units in aliphatic polyesters and that four substituted methyl groups produces more favorable effects on the miscibility TMPAr with aliphatic polyesters. © 1998 John Wiley & Sons, Inc. J Polym Sci 36 : 201–212, 1998 相似文献
6.
7.
Summary This work relates to the tensametric studies of various aliphatic alcohols with a view to see if this technique can be used to assess the structural influence on surface activity. From the study of the homologous series of aliphatic alcohols, it is seen that the surface activity increases with increase in chain length of the alcohols. With lower members of the series the desorption peak is not sharp. There is no regular shift of peak potential from methanol to amylalcohol. For the same alcohol the surface activity increases if the carbon atoms are in a straight chain but decreases if they are branched. Primary alcohols are more surface active than secondary and secondary are more surface active than tertiary alcohols. The peak potential is more negative for normal alcohol than that of tertiary alcohol. Saturated alcohols are more surface active than unsaturated ones having the same number of carbon atoms. The peak potential is also more negative with saturated than with unsaturated. Monohydric alcohols are more surface active than dihydric and dihydric is more surface active than trihydric alcohol having the same number of carbon atoms as in monohydric and dihydric alcohols and in this case the peak potential is more negative with trihydric than with monohydric alcohol. 相似文献
8.
Prof. Dr. David E. Lewis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(64):15829-15841
The name of Menshutkin is most frequently associated with his eponymous reaction (the quaternization of tertiary amines with alkyl halides). However, he made encyclopedic contributions to the field of reaction kinetics, where he carried out extensive studies of the effects of reactant structure on the rates of esterification of monohydric, dihydric and trihydric alcohols with monocarboxylic acids, and monobasic and dibasic carboxylic acids and anhydrides with monohydric alcohols. In these studies, he deduced an order of reactivity of alcohols in esterification on the basis of their reactions with acetic acid, and the effects of acid structure on the rates of esterification based on the reaction of the carboxylic acid with isobutyl alcohol. When his attention later turned to the substitution chemistry of amines, he defined the parameters that affected their reactions: anilines were less reactive than alkylamines, secondary more reactive than primary amines, and the reaction was accelerated by replacing benzene as a solvent with alcohols. The wide-ranging work of Menshutkin, the physical organic chemist, is discussed. 相似文献
9.
L. G. Rogozhina M. V. Kuz’min N. I. Kol’tsov 《Russian Journal of Applied Chemistry》2013,86(4):581-586
A procedure was developed for preparing cyanourethane laquer compositions based on polyisocyanates, polyesters of various structures, and dicyanodiamide. The influence of the polyester structure and component ratio on the properties of the cured laquer coatings was examined, and the compositions allowing preparation of corrosion- and heat-resistant laquer coatings were determined. 相似文献
10.
The effective separation of dimethyl carbonate (DMC) from its methanol mixture through simple, inexpensive and low energy-input method is a promising and challenging field in the process of organic synthesis. Herein, a reversible adsorption strategy through the assistance of superbase and CO2 for DMC/methanol separation at ambient condition was described. The process was demonstrated effectively via the excellent CO2 adsorption efficiency. Notably, the protocol was also suitable to other alcohol (i.e., monohydric alcohol, dihydric alcohol, trihydric alcohol) mixtures. The study provided guidance for potential separation of DMC/alcohol mixture in the scale-up production. 相似文献
11.
Nicola Hoogen Oskar Nuyken 《Journal of polymer science. Part A, Polymer chemistry》2000,38(10):1903-1910
The synthesis and photoreactions of polyesters containing the photolabile triazene group (Ph NN NR2) as well as photocrosslinkable units based on substituted cinnamylidene malonyl moieties are reported. The polyesters were obtained by reacting a triazene containing difunctional alcohol with different substituted cinnamylidene malonic acid dichlorides. Irradiation at λ > 395 nm enables selective photocrosslinking of the cinnamylidene malonyl ester units via [2+2]π‐cycloaddition without affecting the triazene units. The photocrosslinking reaction of the triazene containing polyesters as well as triazene‐free reference polyesters were investigated by UV and IR spectroscopy. After selective photocrosslinking the irradiated polymers became insoluble and no longer exhibited a Tg below decomposition temperature. The crosslinked triazene containing polyesters show strong absorption at λ = 308 nm and are therefore interesting candidates for applications using XeCl excimer laser ablation. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1903–1910, 2000 相似文献
12.
B. T. Ibragimov S. A. Talipov B. N. Dadabaev A. A. Abduvakhabov 《Chemistry of Natural Compounds》1992,28(2):163-168
The first four homologues of the carboxylic acid series and first two homologues of the monohydric alcohol series with gossypol give equimolar H-clathrates with the channel-type structure that are isostructural with gossypolacetic acid. Formic and acetic acids are capable of forming with gossypol a continuous series of solid substitution solutions. The desolvation of the unstable H-clathrates of carboxylic acids and monohydric alcohols form one and the same polymorph of gossypol. By x-ray structural analysis, the structures have been determined of two complexes of gossypol: an H-clathrate with methanol and a solid solution on the replacement of formic acid by acetic acid in a gossypol matrix.Institute of Bioorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 191–197, March–April, 1992. 相似文献
13.
S. H. Mansour N. N. Rozik K. Dirnberger N. E. Ikladious 《Journal of polymer science. Part A, Polymer chemistry》2005,43(15):3278-3288
A series of hyperbranched polyesters was produced by the condensation of the monomer 3,5‐dihydroxybenzoic acid with 1,3,5‐tris(2‐hydroxyethyl) cyanuric acid as a trifunctional central core. The monomer‐to‐core ratio was varied between 3 and 45. The resulting polymers were phenolic‐terminated polyesters. The degree of branching of the polyesters was calculated according to the method described by Fréchet and was found to be in the range of 0.7–0.8. The number‐average molecular weights calculated via 1H NMR spectroscopic degree‐of‐polymerization values are in reasonable agreement with the predicted values derived from the monomer‐to‐core ratio for all prepared polyesters. Thermal and photophysical properties were also studied. Glass‐transition temperatures were determined by differential scanning calorimetry and were found to be relatively independent of the theoretical molar mass. The polyesters were found to be blue emitters, and the solutions exhibited intense fluorescence, with a maximum of 430 nm. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3278–3288, 2005 相似文献
14.
Mohamed A. Abd-Alla Maymouna M. Kandeel Kamal I. Aly Ahmed S. Hammam 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5):523-538
New polyesters formed by interfacial polycondensation of 2,5-bis(4-hydrox-ybenzylidene)cyclopentanone (I) and 2,5-bis(4-hydroxy-3-methoxybenzyli-dene)cyclopentanone (II) with 4,47prime;-diphenic, isophthaloyl, terephthaloyl, adi-poyl, suberoyl, and sebacoyl dichlorides were obtained. The yield and the values of the reduced viscosity of the produced polyesters were found to be affected by the type of organic phase, the quantitative ratio of organic to aqueous phase, the concentration of the hydrogen chloride acceptor, and the contribution of benzyltriethylammonium chloride as a catalyst. In order to characterize these polymers, the necessary model compounds were prepared from I, II, and benzoyl chloride. The resulting polyesters were confirmed by IR, elemental analysis, viscometry, DTA, DSC measurements, and thermogravi-metric analysis. The crystallinities of all polyesters were examined by x-ray analysis, and the electrical properties of the polyesters were tested. 相似文献
15.
Hideaki Matsuda 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(6):1143-1159
Syntheses of novel metal-containing unsaturated polyesters having pendent methacrylate groups obtained by use of divalent metal salts of mono(hydroxyethyl)phthalate-maleic anhydride (MA)-glycidyl methacrylate (GMA) reactions were investigated. The yields were generally high. The metal-containing polyesters obtained were slightly yellow-brown solids, and the molecular weights ranged from 1546 to 2174, depending on the mole ratio of feed. Among them, the polyesters obtained at a feed mole ratio of metal salt:MA:GMA of 1:8:8 were miscible with methyl methacrylate (MMA), giving homogeneous solutions suitable for copolymerization, and the polyesters could be easily cross-linked with MMA to give cured resins. The metal-containing cured polyester resins showed excellent physical properties. Resistance of the resins to chemical attack and boiling water and thermal behavior are also discussed. 相似文献
16.
Piotr Dobrzynski Daniele Fabbri Cristian Torri Janusz Kasperczyk Bozena Kaczmarczyk Malgorzata Pastusiak 《Journal of polymer science. Part A, Polymer chemistry》2009,47(1):247-257
A hydroxylactone ((1R,5S)‐1‐hydroxy‐3,6‐dioxabicyclo [3.2.1] octan‐2‐one, abbreviated as LAC) obtained from catalytic pyrolysis of cellulose was investigated as a monomer in the synthesis of polyesters by ring‐opening polymerization (ROP) with L ‐lactide. Although stannous octoate resulted inactive, ROP initiated by zirconium (IV) acetylacetonate afforded novel copolyesters from LAC and lactide mixtures in the bulk at 110 °C. Copolymers were obtained with different LAC content (from 19 to 45%) with a random microstructure as established by detailed NMR analysis. FTIR spectrometry confirmed the presence in the polymer chain of the OH groups originally present in LAC, which do not react during polymerization due to steric hindrance and inter/intramolecular hydrogen bonding. Reaction with trichloroacetylisocyanide proved that OH groups of the polyesters can be readily derivatized. The application of LAC as a comonomer enables the insertion of the alcohol functionality in polylactide avoiding protection/deprotection steps and potentially expanding the realm of biomaterials affordable from carbohydrate feedstock. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 247–257, 2009 相似文献
17.
Silver(I)‐Catalyzed Three‐Component Reaction of Propargylic Alcohols,Carbon Dioxide and Monohydric Alcohols: Thermodynamically Feasible Access to β‐Oxopropyl Carbonates
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Zhi‐Hua Zhou Dr. Qing‐Wen Song Jia‐Ning Xie Ran Ma Prof. Dr. Liang‐Nian He 《化学:亚洲杂志》2016,11(14):2065-2071
A silver(I)‐catalyzed three‐component reaction of propargylic alcohols, CO2, and monohydric alcohols was successfully developed for the synthesis of β‐oxopropyl carbonates. As such, a series of β‐oxopropyl carbonates were exclusively produced in excellent yields (up to 98 %), even under atmospheric pressure of CO2. The silver catalyst works efficiently for both the carboxylative cyclization of propargylic alcohols with CO2 and subsequent transesterification of α‐alkylidene cyclic carbonates with monohydric alcohols; thus this tandem process performs smoothly under mild conditions. This work provides a versatile and thermodynamically favorable approach to dissymmetric dialkyl carbonates. 相似文献
18.
Yoshitomo Ono Naoyuki Kawashima Hiroto Kudo Tadatomi Nishikubo Takabumi Nagai 《Journal of polymer science. Part A, Polymer chemistry》2005,43(19):4412-4421
The ring‐opening copolymerization of donor–acceptor norbornadiene (D–A NBD) dicarboxylic acid monoglycidyl ester derivatives with D–A NBD dicarboxylic acid anhydride was performed with tetraphenylphosphonium bromide as a catalyst in toluene to produce new norbornadiene (NBD) polyesters containing D–A NBD moieties in the main chain and in the side chain in one step in good yields. The photoisomerization of the D–A NBD moieties in these polyesters proceeded very smoothly to give the corresponding quadricyclane groups. Because these NBD polyesters contained many NBD moieties in the polymer chain, they had the highest capacity for heat storage in the D–A NBD polymers reported so far. The stored thermal energy of the irradiated polyesters was evaluated by differential scanning calorimetry analysis to be approximately 150–190 J/g. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4412–4421, 2005 相似文献
19.
Two strategies designed for the mechanical reinforcement of biodegradable polyesters, such as poly-(ε-caprolactone), poly (L-lactide) and their copolyesters, are described. Both strategies utilize more or less biodegradable thermotropic aromatic polyesters as reinforcing component. However, the structures of the aromatic polyesters differ largely. For strategy I polyesters composed of substituted hydroquinones and substituted terephthalic acids are used (which may contain anhydride groups), whereas the polyesters of strategy II are made up of natural nontoxic monomers such as β-(4-hydroxyphenyl) propionic acid and 4-hydroxybenzoic acid. 相似文献
20.
Al. Al. Berlin 《Polymer Science Series A》2010,52(9):875-883
Some problems related to conservation of existing organic large-scale polymers (polyolefins, PS, PVC, polyesters, PA, etc.) and their replacement with recycled polymers and inorganic polyoxides are revisited: recycling of polymer materials; recyclable sources, such as cellulose, chitin, starch, etc.; enrichment of composites with an inorganic component; inorganic polymers; nanomaterials; and gradient materials. 相似文献