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1.
Graft copolymer of polypropylene and butadiene-acrylonitrile random copolymer was prepared by reactive polymer blending in a melt without solvents. The process was performed by preliminary grafting of maleic anhydride groups to polypropylene and of isocyanate groups to butadiene-acrylonitrile copolymer, followed by blending of the modified polymers. The chemical reactions occurring in the process and the fraction composition of the copolymer were studied.  相似文献   

2.
ABSTRACT

Propyl and butyl half esters of the alternating copolymer isobutylene/maleic anhydride (IB/MAn) are polymers of high acid content (4.67 and 4.38 milliequivalent acid/g polymer). These polymers exhibit good physical performance in thin films, such as absence of cracking and minimal curl. The anhydride ring of the copolymer IB/MAn is opened in refluxing alcohol at atmospheric or elevated pressure; conversion is monitored by an IR probe (1783 vs. 1733 cm?1). The polymers are stable up to about 50 °C. Weight loss corresponding to the reversion to the anhydride structure is observed at higher temperature, with concurrent increase of anhydride resonances in the IR. Thermal stability of the half esters is similar to that of alkyl half esters of the alternating copolymers ethylene/maleic anhydride (EMA) and methyl vinyl ether/maleic anhydride (Gantrez® AN 119). The 1-propanol solution of the propyl half ester of IB/MAn copolymer is a shear thinning fluid, a significant advantage when coating at high speeds.  相似文献   

3.
The syntheses of several monomers, bioactive poly[(3, 4-dihydro-2H-pyran)-alt-(maleic anhydride)] and its derivatives, which have different substituents (e.g., acetoxy, methoxy, ethoxy, methoxycarbonyl, formyl, acetoxymethyl, and tosyloxymethyl groups) in the 2-position of the tetrahydropyran ring of the copolymer backbone, are described. The alternating sequences in copolymers of the dihydropyran derivatives and maleic anhydride were obtained from the equimolar and larger ratios of maleic anhydride to dihydropyran derivative at the onset of the copolymerization. The molecular weights of the copolymers were found to be low (Mn = 1000–7500) due to a transfer reaction of the dihydropyran derivatives. Hydrolyses of the anhydride groups in the copolymers without catalyst afforded poly[(dihydropyran)-alt-(maleic acid)] and its derivatives, whereas an additional three copolymers having substituents, e.g., hydroxy, hydroxymethyl, and carboxyl groups were obtained by hydrolyses of the pendent groups (acetoxy, acetoxymethyl, and methoxycarbonyl) with the aid of a hydroxide catalyst. Carbamoyl groups on the polymers were obtained from ammonolysis of methoxycarbonyl groups. The polymers having mercaptomethyl or aminomethyl groups were obtained by substitution of hydrogen sulfide or ammonia for tosyloxylmethyl groups.  相似文献   

4.
A theoretical model, based on the binomial (Bernoullian) distribution function, was employed for the prediction of functional group distribution in an ethylene-propylene copolymer randomly grafted by maleic anhydride. Using the experimentally determined graft level and molecular weight distribution function, the fraction of polymer molecules with given number of functional groups was calculated. The result was checked experimentally by a fluorescence method based on the excimer formation of pyrene fluorophores attached to the anhydride pendants. The time-resolved fluorescence from the pyrene-labeled copolymer yielded the fraction of polymer molecules with a single functional group. The fraction of singly labeled molecules was compared to the calculated functional group distribution and a reasonable agreement was found between the two. The distribution of grafted maleic anhydride was found to be apparently random among polymer molecules. The distribution of distances was calculated between randomly attached consecutive functional groups along the polymer backbone also. The result indicated that the distance distribution function (similar to a decaying exponential) is dominated by short distances. © 1996 John Wiley & Sons, Inc.  相似文献   

5.
Radiation-induced copolymer grafting of acenaphthylene and maleic anhydride onto polyethylene or EVA film in the vapor phase was carried out and the effect of comonomer sorption on the grafting was studied. When polyethylene film was used as a backbone polymer, the sorption of the binary monomers during the grafting increased linearly as the grafting reaction proceeded. The marked increase was probably caused by the formation of a grafted layer. Particularly, the sorption of maleic anhydride was brought about by the existence of a grafted layer. In grafting onto EVA film, the content of maleic anhddride in the grafted copolymer increased with the increasing content of vinyl acetate in EVA. Continuous measurements of sorption of the comonomers onto EVA and grafted EVA films were carried out by use of an electrobalance. The distinctive feature of the sorption was that the equilibrium sorption of acenaphthylene or maleic anhydride onto the grafted EVA film increased and the diffusion constants for both comonomers decreased markedly with increasing percentage of graft. The copolymer grafting was explained from these results by assuming that the monomer molecules are supplied to the propagating chain ends mostly through a sorbed state on the polymer film.  相似文献   

6.
Radiation-induced solid-state copolymerization of the maleic anhydride–acenaphthylene system was carried out for the purpose of studying the solid-state polymerization of vinyl compounds in a binary system. Melting point measurement confirmed that this binary monomer system forms a eutectic mixture in the solid state. The solid-state polymerization of these monomers proceeds at maximum rate at the eutectic composition, and the polymerization products consist of a mixture of polyacenaphthylene and 1:1 maleic anhydride–acenaphthylene alternating copolymer. Since the 1:1 copolymer was obtained in solution polymerization also and maleic anhydride did not homopolymerize in solid state, it is considered that the solid-state copolymerization of maleic anhydride and acenaphthylene occurs in a liquidlike state at the boundary of the two monomer crystals.  相似文献   

7.
The morphology of blends of styrenic polymers in a matrix of 75% Nylon-6 prepared in a Brabender Plasti-Corder was examined by scanning electron microscopy. Styrene/acrylonitrile copolymers (SAN) form smaller particles as the AN level increases owing to the corresponding decrease in the SAN–polyamide interfacial tension. Various styrenic polymers containing functional groups, maleic anhydride or oxazoline type, that can react with Nylon-6 during melt processing were added to the SAN phase which also led to a decrease in the particle size owing to the graft copolymer formed in situ. The effects of functional group type, amount of functional groups per chain, amount of functional polymer added, and the miscibility of the styrene/maleic anhydride (SMA) and SAN copolymers on the morphology of the styrenic phase in the Nylon-6 matrix are described. © 1992 John Wiley & Sons, Inc.  相似文献   

8.
Reactivity and swelling of nanometer films of alternating maleic anhydride copolymers were investigated in dependence on the kind of comonomer and molar mass of copolymer in aqueous solution at pH 7.4 and pH 3.0 in order to reveal their characteristics under physiological conditions. Fully hydrolyzed (maleic acid) chains of the copolymers with styrene, propene, and ethylene comonomers covalently bound to SiO2 substrates showed a "mushroom" swelling behavior at pH 7.4 with a layer thickness scaling of N3/5. Decreasing the environmental pH was found to induce a comonomer-dependent shrinking or collapse of the immobilized polymers due to the change in ionization. From the swelling kinetics of non-hydrolyzed chains, the time constants and characteristics of swelling and anhydride hydrolysis were determined and found to depend on the type of comonomer. The short- and long-term swelling kinetics [l approximately t and approximately ln(t)1/2] were found to be in agreement with theoretical models of polymer swelling, while at intermediate time scales enhanced swelling was observed due to hydrolysis reaction of maleic anhydride groups. The findings elucidate the variety of properties of maleic anhydride copolymer films under physiological conditions, which can advantageously be applied for biofunctionalization of different templates.  相似文献   

9.
A major challenge in supramolecular polymerization is controlling the stability of the polymers formed, that is, controlling the rate of monomer exchange in the equilibrium between monomer and polymer. The exchange dynamics of supramolecular polymers based on benzene‐1,3,5‐tricarboxamide (BTA) can be regulated by copolymerizing molecules with dendronized (dBTA) and linear (nBTA) ethylene glycol‐based water‐soluble side chains. Whereas nBTAs form long nanofibers in water, dBTAs do not polymerize, forming instead small spherical aggregates. The copolymerization of the two BTAs results in long nanofibers. The exchange dynamics of both the BTA monomers in the copolymer are significantly slowed down in the mixed systems, leading to a more stable copolymer, while the morphology and spectroscopic signature of the copolymers are identical to that of nBTA homopolymer. This copolymerization is the supramolecular counterpart of styrene/ maleic anhydride copolymerization.  相似文献   

10.
Titanocene polymer derivatives with potential antitumor properties were synthesized by interfacial condensation. The preformed polymers used are PAA (polyacrylic acid), CPSMA (1:1 alternating copolymer of styrene and maleic anhydride) and DVEMA (1:2 copolymer of divinyl ether and maleic anhydride). The ratio of practical and theoretical titanium content is 73.6%, 92.2% and 86.2% for PAA, CPSMA and DVEMA polymer derivatives respectively. The IR spectra of the polymer derivatives possess the characteristic absorptions of titanocene. XPS (X-ray photoelectron spectroscopy) of O_(1s) and Ti_(2p3/2) supports the existence of Ti-O bonding.  相似文献   

11.
用3 氨丙基三乙氧基硅烷(APTES)作为偶联剂,通过溶胶 凝胶(Sol Gel)过程制得两相以共价键结合的透明苯乙烯 顺丁烯二酸酐共聚物/SiO2杂化材料.通过FTIR分析等证实了材料有机相与无机相间是以共价键结合的.分析了材料热处理温度和分别用盐酸或氨水作催化剂时对材料溶胶分数的影响、偶联剂及其用量对溶胶 凝胶体系凝胶时间的影响、并研究了杂化材料中无机含量对材料折射率和Tg的影响  相似文献   

12.
The very poor adhesion between films of styrene and acrylonitrile random copolymer (SAN) and maleic anhydride grafted polypropylene (PP‐g‐MA) can be dramatically improved by an intermediate thin layer of SAN bearing groups reactive toward maleic anhydride. The rate of the interfacial reaction, which is controlled by the reactive groups attached to SAN (amine vs. carbamate) and by the method used to build up the sandwich assembly, has a decisive effect on the capability of the SAN‐g‐PP graft copolymer formed at the interface to improve the fracture toughness in direct dependence on its molecular architecture.  相似文献   

13.
Vapor-phase graft copolymerizations of acenaphthylene–maleimide or acenaphthylene–maleic anhydride binary solid monomers onto poly(ethylene-co-vinyl acetate) films were carried out under ultraviolet irradiation. The extent of sorption of single or binary monomers increased with the increasing vinyl acetate content in the backbone polymers. The sorbed binary monomers were mainly composed of acenaphthylene, but the maleimide or maleic anhydride fraction increased with the increasing vinyl acetate content of the films and the composition was little affected by surface hydrolysis. In all series of graft polymerization of single or binary monomers the overall extent of grafting increased with the vinyl acetate content and was suppressed by the surface hydrolysis of the backbone film. The composition of the grafted copolymer, however, differed markedly, depending on the combination of binary monomers. The grafted copolymer in the acenaphthylene–maleimide system was composed mainly of acenaphthylene units, whereas that in the acenaphthylene–maleic anhydride system was composed mainly of maleic anhydride units. The results were compared with those of γ-ray grafting, and it was suggested that the contribution of a direct supply of monomers from vapor phase and the existence of an acetoxy group on the surface of the film should play an important role in the grafting reaction.  相似文献   

14.
本文探索了端羟基液体聚合物,四氢呋喃-环氧丙烷共聚醚,与顺丁烯二酸酐的酯化反应,得到了端羧基乙烯基液体聚合物。 通过控制反应温度,配料比以及选择适宜的催化剂,使端基转化率达到了100%。 用化学分析、核磁共振以及红外光谱分别对端基转化程度和聚合物结构进行了测定。  相似文献   

15.
Abstract

The equimolar, alternating copolymer of isoprene, as well as other conjugated dienes, and maleic anhydride is formed by the radical catalyzed reaction of the conjugated diene with maleic anhydride in the presence of furan as well as with the furan-maleic anhydride Diels-Alder adduct. The retrograde dissociation of the cyclic adduct above 60°C regenerates furan and maleic anhydride which in the presence of isoprene forms the isoprene-maleic anhydride ground state complex. The latter yields the corresponding cyclic adduct in the absence of a radical catalyst and undergoes excitation and homopolymerization in the presence of a catalyst.  相似文献   

16.
The novel biodegradable copolymer PDLLA-(MAH-Diol)_n-PDLLAwith unsaturated bond was synthesized by copolymerizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly(ethylene glycol), using p- toluene sulphonic acid as catalyst. The new copolymer has improved hydrophilicity and fexibility. The structure and properties of the novel polymers were studied by FTIR, NMR, GPC-MALLS and DSC.  相似文献   

17.
Subcritical water is a benign and effective media for polymer degradation. On subcritical water treatment in the presence of an aminoalcohol, unsaturated polyesters crosslinked with styrene were decrosslinked, and a linear polystyrene derivative bearing hydroxy-terminated side-chains was recovered. After modification of the hydroxy groups with maleic anhydride, the polystyrene derivative was re-crosslinked with styrene to form a networked structure again. The resulting solid was degradable by subcritical water treatment in the presence of the aminoalcohol to give another polystyrene derivative bearing hydroxy groups. These processes could be repeated successfully, demonstrating the applicability as a novel recycling system of thermosetting resins. The polystyrene derivative was also re-crosslinked again on heating with an alternative copolymer of styrene and maleic anhydride due to the formation of linkage between the hydroxy groups and carboxylic anhydride moieties.  相似文献   

18.
Bilayer film Fourier transform infrared (FTIR) model experiments are designed to provide a well-defined interface for study which can be probed by infrared spectroscopy during the interdiffusion and reaction of two reactive polymers. This provides a model experiment to determine the kinetics and extent of reaction between functionalized polymers during reactive polymer blending. This type of experiment provides data on the reaction at a stagnant interface which is necessary for the analysis of the interface while it is simultaneously undergoing deformation. It is also useful as a screening or preliminary experiment on reactive blending systems in that the extent of reaction may be followed for different systems at different temperatures. Experiments reported here trace the reaction of a styrene–maleic anhydride copolymer with two different amine terminated polymers. Results are obtained for the interdiffusion and reaction of a styrene-maleic anhydride copolymer with two amine terminated polymers: a butadiene-acrylonitrile copolymer and Nylon 11. The kinetics from these experiments include contributions due to both interdiffusion and chemical reaction. The chemical reaction kinetics may be isolated from the diffusion kinetics by performing experiments on well-mixed systems which are prepared by casting films of the polymer mixtures from a mutual solvent. © 1994 John Wiley & Sons, Inc.  相似文献   

19.
Cis-platinum complexes used as antitumor drugs were attached onto preformed polymers toreduce the toxicity. Either alternating copolymer of styrene and maleic anhydride (CPSMA) orpolyacrylic acid (PAA) is readily dissolved in alkaline solution. The cis-platinum complexes areeasily converted into water soluble species when treated by silver nitrate in water. The expectedproducts could be obtained when the two aqueous solutions were brought together. The productswere characterized by elementary analysis, IR and XPS. The polymer derivatives could exchangeligands with nucleophilic groups in biological environment and also exhibit antineoplastic activity.  相似文献   

20.
The solid-state polymerization of maleimide by γ- and ultraviolet irradiation was carried out in binary systems with succinimide, maleic anhydride, and acenaphthylene. Polymaleimide obtained from the solid-state polymerization of maleimide by γ-rays was amorphous, while that obtained from the solid-state polymerization by ultraviolet rays was highly crystalline. In the maleimide–succinimide system the rate of polymerization reached a maximum nearly at the eutectic composition when the polymerization was carried out by γ-irradiation. With ultraviolet irradiation the rate of polymerization became higher with increasing content of succinimide in the feed. In the maleimide–maleic anhydride system a copolymer of both constituents was formed by γ-irradiation, but almost no homopolymer was produced. On the other hand, two kinds of polymers, a crystalline copolymer and an amorphous one, were produced by ultraviolet irradiation. The results were compared with those obtained from the copolymerization in solution. In the maleimide-acenaphthylene system the main products with ultraviolet irradiation was the dimer of acenaphthylene.  相似文献   

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