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1.
A new synthesis of poly(amido-amine)s from bis (secondary amine)s and acryloyl chloride has been studied, leading to polymers in which the amido- and amino-groups are randomly arranged along the macromolecular chain. A poly(amido-amine) based on piperazine, chosen as the mother compound, has been fully characterized by 13C n.m.r. as well as by identification and quantitative evaluation of its hydrolysis products.  相似文献   

2.
Stimulated by the outstanding membrane properties of poly(amidesulfonamide)s (PASAs), 2 series of copolymers were synthesized by low-temperature solution polycondensation of either the diamino monomer N,N′-bis(4-aminophenylsulfonyl)piperazine (1A) or N,N′-bis(4-aminophenylsulfonyl)-2,5-dimethylpiperazine (1B) with a mixture of isophthaloyl and terephthaloyl chloride. All of these copolymers were adequately characterized by intrinsic viscosity measurements, infrared (IR) spectroscopy, 1H and 13C nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction. The effects of various feed ratios of isophthaloyl–terephthaloyl chloride on the physical properties of the copolymers were investigated. In particular, the crystallinity of PASA copolymers was found to be trimmed down by copolymerizing diamino monomer 1A or 1B with increasing fraction of isophthaloyl chloride. It was envisioned that when the crystallinity of the PASA membranes decreased, permeation flux would be preferably increased at a minimum sacrifice of separation characteristics in the pervaporation process. Experimental findings, however, revealed that the resulting permeation flux and separation factor of pervaporation membranes derived from various copolymers were both within the same order of magnitude. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 47–60, 1998  相似文献   

3.
Hyperbranched poly(silyl ester)s were synthesized via the A2 + B4 route by the polycondensation reaction. The solid poly(silyl ester) was obtained by the reaction of di‐tert‐butyl adipate and 1,3‐tetramethyl‐1,3‐bis‐β(methyl‐dicholorosilyl)ethyl disiloxane. The oligomers with tert‐butyl terminal groups were obtained via the A2 + B2 route by the reaction of 1,5‐dichloro‐1,1,5,5‐tetramethyl‐3,3‐diphenyl‐trisi1oxane with excess amount of di‐tert‐butyl adipate. The viscous fluid and soft solid poly(silyl ester)s were obtained by the reaction of the oligomers as big monomers with 1,3‐tetramethyl‐1,3‐bis‐β(methyl‐dicholorosilyl)ethyl disiloxane. The polymers were characterized by 1H NMR, IR, and UV spectroscopies, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The 1H NMR and IR analysis proved the existence of the branched structures in the polymers. The glass transition temperatures (Tg's) of the viscous fluid and soft solid polymers were below room temperature. The Tg of the solid poly(silyl ester) was not found below room temperature but a temperature for the transition in the liquid crystalline phase was found at 42°C. Thermal decomposition of the soft solid and solid poly(silyl ester)s started at about 130°C and for the others it started at about 200°C. The obtained hyperbranched polymers did not decompose completely at 700°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3430–3436, 2006  相似文献   

4.
Two series of thermoplastic poly(ester–siloxane)s, based on poly(dimethylsiloxane) (PDMS) as the soft segment and poly(butylene terephthalate) as the hard segment, were synthesized by two‐step catalyzed transesterification reactions in the melt. Incorporation of soft poly(dimethylsiloxane) segments into the copolyester backbone was accomplished in two different ways. The first series was prepared based on dimethyl terephthalate, 1,4‐butanediol and silanol‐terminated poly(dimethylsiloxane) (PDMS‐OH). For the second series, the PDMS‐OH was replaced by methyl diesters of carboxypropyl‐terminated poly(dimethylsiloxane)s. The syntheses were optimized in terms of both the concentration of catalyst, tetra‐n‐butyl‐titanate (Ti(OBu)4), and stabilizer, N,N′‐diphenyl‐p‐phenylene‐diamine, as well as the reaction time. The reactions were followed by measuring the inherent viscosities of the reaction mixture. The molecular structures of the synthesized poly(ester–siloxane)s were verified by 1H NMR spectroscopy, while their thermal properties were investigated using differential scanning calorimetry. © 2001 Society of Chemical Industry  相似文献   

5.
A new indane containing unsymmetrical diamine monomer ( 3 ) was synthesized. This diamine monomer leads to a number of novel semifluorinated poly (ether imide)s when reacted with different commercially available dianhydrides like benzene‐1,2,4,5‐tetracarboxylic dianhydride (PMDA), benzophenone‐3,3′, 4,4′‐tetracarboxylic dianhydride (BTDA), 4,4′‐(hexafluoro‐isopropylidene)diphthalic anhydride (6FDA), 4,4′‐oxydiphthalic anhydride (ODPA), and 4,4′‐(4,4′‐Isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) by thermal imidization route. All the poly(ether imide)s showed excellent solubility in several organic solvents such as N‐methylpyrrolidone (NMP), N,N‐dimethylformamide (DMF), N,N‐dimethylacetamide (DMAc), tetrahydrofuran (THF), chloroform (CHCl3) and dichloromethane (DCM) at room temperature. These light yellow poly (ether imide)s showed very low water absorption (0.19–0.30%) and very good optical transparency. Wide angle X‐ray diffraction measurements revealed that these polymers were amorphous in nature. The polymers exhibited high thermal stability up to 526°C in nitrogen with 5% weight loss, and high glass transition temperature up to 265°C. The polymers exhibited high tensile strength up to 85 MPa, modulus up to 2.5 GPa and elongation at break up to 38%, depending on the exact polymer structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

6.
This paper reports the synthesis of four different trifluoromethyl-substituted poly(arylene ether)s on the basis of 2,2-bis(4-hydroxyphenyl)hexafluoropropane (bisphenol AF) and various difluoro- or dinitrobiphenyl or terphenyl monomers in the course of a step-growth polycondensation. Besides a comparison between the polymerisability of the different monomer combinations, a main focus of this work lies on the NMR characterization of these poly(arylene ether)s. Poly(arylene ether)s with sufficiently high number average molecular weights were sulfonated by fuming sulfuric acid or chlorosulfonic acid and investigated in terms of membrane properties relevant for fuel cell applications.  相似文献   

7.
A series of novel thermoplastic elastomers based on ABA‐type triblock prepolymers, poly[(propylene oxide)–(dimethylsiloxane)–(propylene oxide)] (PPO‐PDMS‐PPO), as the soft segments, and poly(butylene terephthalate) (PBT), as the hard segments, was synthesized by catalyzed two‐step melt transesterification of dimethyl terephthalate (DMT) with 1,4‐butanediol (BD) and α,ω‐dihydroxy‐(PPO‐PDMS‐PPO) (M?n = 2930 g mol?1). Several copolymers with a content of hard PBT segments between 40 and 60 mass% and a constant length of the soft PPO‐PDMS‐PPO segments were prepared. The siloxane‐containing triblock prepolymer with hydrophilic terminal PPO blocks was used to improve the compatibility between the polar comonomers, i.e. DMT and BD, and the non‐polar PDMS segments. The structure and composition of the copolymers were examined using 1H NMR spectroscopy, while the effectiveness of the incorporation of α,ω‐dihydroxy‐(PPO‐PDMS‐PPO) prepolymer into the copolyester chains was controlled by chloroform extraction. The effect of the structure and composition of the copolymers on the transition temperatures (Tm and Tg) and the thermal and thermo‐oxidative degradation stability, as well as on the degree of crystallinity, and some rheological properties, were studied. Copyright © 2006 Society of Chemical Industry  相似文献   

8.
Novel water‐soluble unsaturated poly(ether amide)s (PEAs) were synthesized by low‐temperature polycondensation of fumaryl chloride and amine‐terminated poly(ethylene glycol) (Jeffamine®). The unsaturated copolymers were further chemically modified with thiols to provide reactive pendant functional groups. Hydrogels based on these copolymers were prepared by copolymerization of the PEA with N‐vinyl pyrrolidone exposure to ultraviolet (UV) irradiation. The resulting hydrogels exhibited a high swelling ratio, and the magnitude of swelling depended on the molecular weight of Jeffamine®. The swelling ratio and equilibrium water content tended to increase with increasing chain length of the Jeffamine® used in copolymer synthesis. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 913–920, 1999  相似文献   

9.
10.
Temperature and pH‐responsive interpenetrating polymer network (IPN) hydrogels, constructed with poly(methacrylic acid) (PMAA) and poly(vinyl alcohol) (PVA), by a sequential IPN method, were studied. The characterization of IPN hydrogels was investigated by Fourier‐transform infrared spectroscopy, differential scanning calorimetry (DSC) and swelling under various conditions. The IPN hydrogels exhibited relatively high swelling ratios, in the range 230–380 %, at 25 °C. The swelling ratios of the PMAA/PVA IPN hydrogels were pH and temperature dependent. DSC was used for the quantitative determination of the amounts of freezing and non‐freezing water. The amount of free water increased with increasing PMAA content in the IPN hydrogels. Copyright © 2004 Society of Chemical Industry  相似文献   

11.
The hydrolysis behaviour of lactic acid based poly(ester-urethane)s has been studied in a buffer solution of pH 7·00 at 37 and 55°C. Samples were prepared using a straight two step lactic acid polymerization process. The lactic acid was first polymerized by condensation with a low molecular weight by hydroxyl terminated telechelic prepolymer and the molecular weight then was increased with a chain extender such as a diisocyanate. In the hydrolysis study, the effect on the hydrolysis rate of different stereostructures (different amount of D -units in the polymer chain) and the length of the ester units were studied. The rate of hydrolysis was examined by various techniques including weighing (water absorption and weight loss), GPC (molecular weight and polydispersity), and DSC (thermal properties). GPC measurements showed that at 37°C the weight average molecular weight of the poly(ester-urethane)s started to decrease slowly during the first week of hydrolysis, but that at 55°C the weight average molecular weight decreased dramatically during the first week of hydrolysis. Significant mass loss occurred later at both temperatures. © 1998 Society of Chemical Industry  相似文献   

12.
A novel monomer of tetrachloroterephthaloyl chloride (TCTPC) was prepared by the chlorination of terephthaloyl chloride catalyzed by ferric chloride at 175–180°C for 10 h and confirmed by FTIR, MS, and elemental analysis. Five new polychloro substituted poly(aryl ether ketone sulfone)s (PEKSs) with inherent viscosities of 0.68–0.75 dL/g have been prepared from 4,4′‐diphenoxydiphenylsulfone, 4,4′‐bis(2‐methylphenoxy) diphenylsulfone, 4,4′‐bis(3‐methylph‐enoxy)diphenylsulfone, 4,4′‐bis(2,6‐dimethylphenoxy)diphenylsulfone, and 4,4′‐bis(1‐naphthoxy)‐diphenylsulfone with TCTPC by electrophilic Friedel‐Crafts acylation in the presence of DMF with anhydrous AlCl3 as a catalyst in 1,2‐dichloroethane, respectively. These polymers having weight–average molecular weight in the range of 76,600–83,900 are all amorphous and show high glass transition temperatures ranging from 213 to 250°C, the 5% weight loss temperature over 450°C, high char yields of 60–67% at 700°C in nitrogen and good solubility in CHCl3 and polar solvents such as DMF, DMSO, and NMP at room temperature. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 85.1–90.8 MPa, Young's moduli of 2.52–3.24 GPa, and elongations at break of 21.2–27.2%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

13.
Poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains were synthesized by polycondensation of each of the two bisphenol monomers viz, 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane and 1,1‐bis(4‐hydroxyphenyl)‐3‐pentadecyl cyclohexane with activated aromatic dihalides namely, 4,4′‐difluorobenzophenone, and 1,3‐bis(4‐fluorobenzoyl)benzene in a solvent mixture of N,N‐dimethylacetamide and toluene, in the presence of anhydrous potassium carbonate. Polymers were isolated as white fibrous materials with inherent viscosities and number average molecular weights in the range 0.70–1.27 dL g?1 and 76,620–1,36,720, respectively. Poly(ether ether ketone)s and poly(ether ether ketone ketone)s were found to be soluble at room temperature in organic solvents such as chloroform, dichloromethane, tetrahydrofuran, and pyridine and could be cast into tough, transparent, and flexible films from their solutions in chloroform. Wide angle X‐ray diffraction patterns exhibited a broad halo at around 2θ = ~ 19° indicating that the polymers containing pentadecyl chains were amorphous in nature. In the small‐angle region, diffuse reflections of a typically layered structures resulting from the packing of pentadecyl side chains were observed. The temperature at 10% weight loss, obtained from TG curves, for poly(ether ether ketone)s and poly(ether ether ketone ketone)s were in the range 416–459°C, indicating their good thermal stability. A substantial drop in glass transition temperatures (68–78°C) was observed for poly(ether ether ketone)s and poly(ether ether ketone ketone)s due to “internal plasticization” effect of flexible pendant pentadecyl chains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

14.
Three new diamines derived from epoxide compounds were synthesized. The preparation of diamine monomers implied the reaction between a phenoxyalkyloxirane (alkyl: H, methyl, isopropyl) and bisphenol A, obtaining the respective aliphatic diols, which produced the corresponding dinitro derivatives. Finally, these derivatives were reduced by using palladium/carbon activated as catalyst and hydrazine as a hydrogen source. Then, six oligomeric poly(ether-azomethine)s (PEAzMs) were obtained from a polycondensation reaction between the new diamines and bis(4-formylbiphenyl-4-yl)dialkylsilane (alkyl: methyl, phenyl) with 84–93% yields. The structural characterization of the diamines and PEAzMs was performed by elemental analysis, infrared spectroscopy, and nuclear magnetic resonance spectroscopy (1H, 13C, and 29Si). Furthermore, polymers were analyzed by solubility tests, gel permeation chromatography, ultraviolet–visible (UV–vis) spectroscopy, thermogravimetry, and differential scanning calorimetry analysis. The results showed PEAzMs with 2–11 repetitive units, where the design of the monomers allowed to obtain improved solution processability in comparison with previously reported silylated poly(azomethine)s and good thermal stability. Additionally, all samples showed high transparency in the UV–vis region. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48055.  相似文献   

15.
Polyelectrolyte complex based on chitosan and acrylic acid monomer by photoinitiated free‐radical polymerization in the absence of crosslinker showed a large transition in swelling in response to changes in pH of surrounding medium. Their ability to swell arises from polyelectrolyte interactions and molecular structure of the complex. The main properties of interest that related to the molecular structure, swelling volumes, glass transition temperature, and elastic modulus of the complex were investigated. The effect of water content, the only variable in the sample component, played an important role in molecular structure of the complex and as a consequence, the extent of intermolecular linkage, especially amide bonds which in turn governed the degree of swelling of the polyelectrolyte complex in this study. The decreased degree of swelling and higher temperature shift of glass transition temperature was found with increased water content, whereas increased modulus of elasticity of dry complex was found in lower water content of synthesis component. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1025–1035, 2002  相似文献   

16.
A series of novel benzhydrol-containing poly(amide-imide)s (PAIs) have been prepared from a new diimide-dicarboxylic acid, N,N′-bis(4-hydroxycarbonyl)-benzhydrol-3,3′,4,4′-tetracarboxydiimide (BHTDA-DIA), with various diamines by direct polycondensation using triphenyl phosphite and pyridine as condensing agents. The polymers obtained had inherent viscosities of 0.35–0.96 dl g−1. All these PAIs, except polymer PAI-2, were soluble in N-methyl-2-pyrrolidinone and N,N-dimethylacetamide containing LiCl (1 wt%). Tough and flexible PAI films could be obtained by casting PAIs from their DMAc or NMP solutions, except for polymer PAI-2. The polymer films had a tensile strength of 93–111 MPa, an elongation at break range of 4–6%, and an initial modulus range of 2.7–3.8 GPa. The glass transition temperatures of most polymers were found to be above 255 °C. These polymers were fairly stable up to a temperature around or above 400 °C, and lost 10% weight in the range 426–507 °C in nitrogen and 423–515 °C in air. © 1999 Society of Chemical Industry  相似文献   

17.
Graphene oxide was modified with third-generation poly(amidoamine) (PAMAM) to obtain dendrimer-grafted GO (DGO) with high content of functional groups. DGO's amine groups were conjugated with S-(thiobenzoyl)thioglycolic acid as proved by XPS and poly(acrylic acid) was grafted onto surface via RAFT polymerization (DGO@PAA). FT-IR results approved the synthesis of samples whereas TGA revealed 40.3% grafting of PAA. XRD patterns showed that with further modification, d-spacing increased. According to Raman spectra, modification resulted in more disordered structure whereas DGO@PAA showed a high value of ID/IG. Morphological studies were performed by SEM and TEM that showed a polymeric layer covered the surface of nanosheets.  相似文献   

18.
A new category of linear poly(ether-ketone)s IVa–d and copoly(ether-ketone)s Va–f containing diarylidenecycloalkanone moieties in the main chain has been synthesized by solution polycondensation of 4,4′-bis (chloroacetyl)diphenylether I , with different phenoxides of diarylidenecycloalkanones IIa–d . The model compound III was synthesized from the monomer I with sodium phenoxide in DMF and K2CO3, and its structure was confirmed by elemental and spectral analyses. The resulting polyketones and copolyketones were characterized by elemental and spectral analyses, beside solubility and viscometry measurements. The thermal properties of those polymers were evaluated by TGA and DTA measurements and correlated to their structural units. X-ray analysis showed that polymers having some degree of crystallinity in the region 2θ = 5–60°. In addition, the biological screening and morphological properties of selected examples of the polymers were tested. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

19.
9,9‐Bis(4‐hydroxyphenyl)xanthene (BHPX), a bisphenol monomer, was synthesized in 82% yield from xanthenone in a one‐pot, two‐step synthetic procedure. Four novel aromatic poly(ether ketone)s (PEKs) based on BHPX were prepared via a nucleophilic aromatic substitution polycondensation with four difluorinated aromatic ketones. The polycondensation proceeded in tetramethylene sulfone in the presence of anhydrous potassium carbonate and afforded the new cardo PEKs in nearly quantitative yields with inherent viscosities of 0.77–0.85 dL/g. High molecular weight PEKs having number‐average molecular weights (Mn's) in the range of 38,900–40,600 g/mol with the polydispersity index ranged from 1.97 to 2.06 are all amorphous and show high glass transition temperatures ranging from 210°C to 254°C, excellent thermal stability, and the temperatures at the 5% weight loss are over 538°C with char yields above 60% at 700°C in nitrogen. These new PEKs are all soluble in polar aprotic solvents such as N‐methyl‐2‐pyrrolidone and N, N′‐dimethylacetamide and could also be dissolved in chloroform and tetrahydrofuran. All the polymers formed transparent, strong, and flexible films with tensile strengths of 78–84 MPa, Young's moduli of 2.54–3.10 GPa, and elongations at break of 14–18 %. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

20.
The synthesis of Ag nanoparticles stabilized Poly(N,N’-methylene bis-acrylamide N-aminoethyl piperazine)(MBA-AEPZ) was reported. The effects of hyperbranched polymer generation number on the size and size distribution of Ag nanoparticles were studied, which were determined from the UV plasmon absorption spectra and transmission electron microscopic (TEM) analysis. These data show that the changes of size (8.7, 9.6 and 10.2 nm) were observed with increase in Poly(MBA-AEPZ) generation number (1, 3 and 5) at the same Ag+:NH2 group ratio (M:D).  相似文献   

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