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1.
A novel Sm(III)–hyperbranched poly(ester‐amide) complex (Sm(III)–HBPEA) was synthesized, and characterized using Fourier transform infrared, 13C NMR and fluorescence spectroscopy and thermogravimetric analysis. Under the conditions used, HBPEA chelates to Sm3+ ions mainly via oxygen and nitrogen atoms of functional groups on the HBPEA chain. Modes of bonding of carboxyl groups, terminal hydroxyl groups and amide carbonyl structures may play the most important role in the coordination interaction. On excitation with UV light, the complex exhibits characteristic emission of both HBPEA and Sm3+. The presence of Sm3+ ions slightly accelerates HBPEA decomposition. Copyright © 2010 Society of Chemical Industry  相似文献   

2.
A novel antistatic agent poly(ether‐ester‐amide) (PEEA) based on caprolactam, polyethylene glycol, and 6‐aminocaproic acid was successfully synthesized by melting polycondensation. The structure, thermal properties, and antistatic ability of the copolymer were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analyses, and ZC36 megohmmeter. Test results show that PEEA is a block copolymer with a melting point of 217°C and a thermal decomposition temperature of 409°C, together with a surface resistivity of 108 Ω/sq. Antistatic poly(acrylonitrile‐co‐butadiene‐co‐styrene) (ABS) materials were prepared by blending different content of PEEA to ABS resin. The antistatic performances, morphology, and mechanical properties were investigated. It is indicated that the surface resistivity of PEEA/ABS blends decrease with the increasing PEEA content, and the excellent antistatic performance is obtained when the antistatic agent is up to 10–15%. The antistatic performance is hardly influenced by water‐washing and relative humidity, and a permanent antistatic performance is available. The antistatic mechanism is investigated. The compatibility of the blends was studied by scanning electron microscopy images. The ladder distribution of antistatic agent is formed, and a rich phase of antistatic agent can be found in the surface layer. The elongations at break of the blend are improved with the increasing antistatic agent; the tensile strength and the notched impact strength kept almost the same. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.  相似文献   

3.
A new family of biodegradable amino‐acid‐based poly(ester amide)s (AA–PEAs) and amino‐acid‐based poly(ether ester amide)s (AA–PEEAs) consisting of reactive pendant functional groups (? COOH or ? NH2) were synthesized from unsaturated AA–PEAs and AA–PEEAs via a thiol–ene reaction in the presence of a radical initiator (2,2′‐azobisisobutyronitrile). The synthetic method was a one‐step reaction with near 100% yields under mild reaction conditions. The resulting functional AA–PEA and AA–PEEA polymers were characterized by Fourier transform infrared spectroscopy, NMR, and differential scanning calorimetry. These new functional AA–PEA and AA–PEEA derivatives had lower glass‐transition temperatures than the original unsaturated AA–PEA and AA–PEEA polymers, and their solubility in some organic solvents also improved. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

4.
A systematic investigation by FTIR spectroscopy was undertaken on blends of poly(propylene carbonate) (PPC) and bisphenol A (BPA). It provided direct evidence of the hydrogen bond (H‐bond) between BPA O? H groups and PPC C?O groups. Using a curve‐fitting method, qualitative as well as quantitative information concerning this H‐bond interaction was obtained. The inter‐H‐bond in PPC/BPA blends was weaker than the self‐H‐bond in BPA. The absorptivities of the free and the H‐bonded C?O groups were nearly equal. The fraction of H‐bonded C?O in the blends increased with BPA content and leveled off at a value close to 40 %. Finally, FTIR–temperature measurements of pure PPC and a representative blend were reported: by monitoring the peak areas of C?O absorptions, the dissociation of the inter‐H‐bonds and the thermal degradation of PPC were observed. It revealed that the presence of BPA clearly retarded the thermal degradation of PPC. Copyright © 2004 Society of Chemical Industry  相似文献   

5.
Cellulose nanocrystals (CNCs) organogels were first produced from aqueous dispersion through solvent exchange of CNCs to acetone via a simple sol‐gel process. After mixing the organogels with poly(propylene carbonate) (PPC) in dimethylformamide followed by solution casting, green nanocomposites were obtained with CNCs well dispersed in PPC polymer matrix which was confirmed by scanning electron microscopy observations. Differential scanning calorimeter analysis revealed that glass transition temperature of the nanocomposites was slightly increased from 34.0 to 37.4°C. Tensile tests indicated that both yield strength and Young's modulus of CNCs/PPC nanocomposites were doubled by adding 10 wt % CNCs. However, poor thermal stability of PPC occurred after incorporating with CNCs due to the thermo‐sensitive sulfate groups located on the surface of CNCs. Furthermore, PPC became more hydrophilic because of the inclusion of CNCs according to the water contact angle measurement. The enhanced mechanical and hydrophilic properties, coupled with the inherent superior biocompatibility and degradability, offered CNCs/PPC composites potential application in biomedical fields. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40832.  相似文献   

6.
A new type of unsaturated poly(ester‐amide) viz maleic anhydride‐phthalic anhydride‐ethylene glycol‐neopentylene glycol‐glycin copolymer was prepared by melt polycondensation. The copolymer was characterized by FT‐IR, gel permeation chromatography, and thermal gravimetric analysis. The molecular structure of crosslinked unsaturated poly(ester‐amide) was determined by wide‐angle X‐ray diffraction. Hydroxyapatite (n‐HA) was used to boost up the new unsaturated poly (ester‐amide), the flexural properties of n‐HA/unsaturated poly(ester‐amide) nanocomposites with different n‐HA content were measured. Studies of degradation behavior were carried out in simulated body fluid at pH 7.4 and 37°C, the flexural strength changes and cumulative mass loss of n‐HA/ unsaturated poly(ester‐amide) nanocomposites were measured at different degradation times. The n‐HA/unsaturated poly(ester‐amide) nanocomposites was hydrolyzed in 1M NaOH standard solution at room temperature to study the mass loss with different n‐HA contents. All the preliminary results suggested that n‐HA/unsaturated poly(ester‐amide) nanocomposites might be potentially used as a new type of bone fixation material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

7.
A novel unsaturated poly(ester‐amide) network (UPEAN) that contains isolated C? C double bonds, monomeric lactate sequences, rigid benzyl side‐groups, amide groups and crosslinking points has been designed and synthesized. The structure of the intermediate and UPEAN was verified with Fourier transform infrared spectroscopy. Pores in UPEAN generated in situ were examined with scanning electron microscopy. Differential scanning calorimetry analysis shows that UPEAN is amorphous and its glass transition temperature is around 34 °C. It is found that UPEAN exhibits thermosensitive shape‐recovery characteristics. The maximum percentage weight loss of UPEAN is 10 and 42% after immersing the samples in active sludge at ambient temperature for 146 days and in 0.1 mol L?1 phosphate‐buffer saline at 37 °C for 103 days, respectively, which suggests that UPEAN is degradable. Copyright © 2007 Society of Chemical Industry  相似文献   

8.
The synthesis and characterization of a new series of chiral poly(ester‐amide)s are reported. They were prepared by the simple reaction of diacid chlorides with biphenolic azo chromophores and optically active dihydroxy compound (isosorbide) in dimethyl acetamide at 100 °C. The polymers containing isosorbide units were optically active. The polymers showed Tg between 100 and 190 °C and were stable up to 400 °C. These poly(ester‐amide)s showed a positive solvatochromism in UV–visible absorption spectra. Second harmonic generation activities were measured by the powder method. © 2001 Society of Chemical Industry  相似文献   

9.
超支化聚酰胺酯对聚乳酸增韧改性的研究   总被引:5,自引:0,他引:5  
采用熔融共混的方法,用生物可降解的超支化聚酰胺酯(HBP)对聚乳酸(PLA)进行增韧改性,制备出具有良好韧性的PLA复合材料。对不同HBP含量的共混物的红外光谱、热性能和力学性能进行了测试和分析。红外光谱显示PLA和HBP间存在氢键作用。HBP的加入使PLA的结晶度从30.99%降低到18.58%。当HBP含量增加到10%时,PLA共混物的拉伸强度略有提高,且断裂伸长达到43.06%。结果表明:HBP的加入对PLA起到了很好的增韧作用。  相似文献   

10.
A series of poly(ester‐amide)s based on an ester group containing lithocholic acid derivative [3‐(3‐carboxypropionyl) lithocholic acid] and several aromatic diamines (naphthalene‐1,5‐diamine, 4,4′‐diaminodiphenyl ether, 4,4′‐diaminodiphenylmethane, 4,4′‐diaminodiphenylsulfone, benzidine, m‐phenylenediamine, p‐phenylenediamine, and tetraphenylthiophene diamine) was synthesized and characterized by solubility, viscosity, IR, differential scanning calorimetry, thermogravimetric analysis, and optical microscopy. The polymers were soluble in most of the organic solvents and had inherent viscosities in the range of 0.21–0.38 dL/g. All the polymers exhibited a nematic mesophase, but only on shearing. Thermal transitions due to mesophase formation were not seen in the differential scanning calorimetry thermograms. However, the liquid crystalline character of the polymers was observed under an optical microscope. Thermogravimetric analyses revealed the maximum decomposition temperature was 390–435°C for these polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 73–80, 2006  相似文献   

11.
New cellulose‐based hyperbranched derivatives having different degrees of branching were prepared via reaction of cellulose with acrylonitrile followed by reduction of nitrile groups and successive reaction with acrylonitrile or methylacrylate. First‐ (G = 1) and half‐ (G = 0.5) generation cellulose‐based hyperbranched poly(propylene imine) or poly(amido amine) derivatives have been prepared with high reaction yield. The structure of the prepared derivatives was confirmed by Fourier transform infrared and 13C nuclear magnetic resonance (13C NMR). Thermal stability of the different cellulose‐based hyperbranched derivatives were examined using thermogravimetric analysis to study the effect of branching on the thermal decomposition parameters. The onset degradation temperature and the activation energy of the thermal degradation decreased with increasing the branching of the cellulose‐based hyperbranched derivatives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2079–2087, 2006  相似文献   

12.
The specific interactions between several low‐molecular‐weight diamino compounds and poly(ε‐caprolactone) (PCL) have been investigated by FT‐IR. It was found that PCL and 3,3′‐diaminodiphenylmethane (3,3′‐DADPM) interact through strong intermolecular hydrogen bonds in the blend. Thermal and mechanical properties of PCL/3,3′‐DADPM blends were investigated by DSC and tensile measurements, respectively. The glass transition temperature of the blend increases while both the melting point and the elongation‐at‐break of the blend decrease with the increase of 3,3′‐DADPM content. Besides 3,3′‐DADPM, several other low‐molecular‐weight compounds containing two amino groups, such as o‐phenylenediamine or 1,6‐diaminohexane, were also added into PCL and the corresponding blend systems were investigated by FT‐IR and DSC. The effect of the chemical structure of the additives on the properties of PCL is discussed. © 2001 Society of Chemical Industry  相似文献   

13.
A novel linear lactic acid‐based poly(ester‐amide) (LLPEA) was prepared via polyaddition of toluene‐2,4‐diisocyanate (TDI) with ethylene lactate succinic half‐ester diacid (ELDA), which contained ethylene glycol lactate sequences and derived from lactic acid. LLPEA was characterized with FTIR, GPC, DSC, TGA, and XRD. The weight average molecular weight and its polydisperse index of LLPEA could be 1.0 × 105 and 2.0, respectively. DSC and XRD analysis showed that LLPEA was a semicrystalline polymer. The glass transition temperature, melting temperature, and the thermal decomposition temperature (50 wt %) of LLPEA were ?2, 94, and ~415°C, respectively. The contact angle determination indicated that LLPEA was a hydrophilic polymer. It was found that the yield strength, tensile strength, and elastic module of LLPEA could be 8.8, 9.6, and 176 MPa, respectively. In addition, the weight loss percentage of LLPEA was 2.5% after 157‐days immersion in activated sludge at ambient temperature, which suggested that LLPEA was degradable. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3805–3808, 2006  相似文献   

14.
Poly(propylene carbonate) (PPC) was used as a toughening agent for improving the brittleness of cured epoxy resins (EP). Methyl tetrahydrophthatic anhydride (MTHPA) was used as a curing agent. The activation energies for the reactions of PPC/MTHPA and EP/MTHPA measured by FTIR were 115.8 and 66.5 kJ/mol, respectively, while for the composite system of PPC/EP/MTHPA, the activation energy obtained from DSC was 52.9 kJ/mol. Gel contents, DMA, and DSC displayed that the cured resins of PPC/EP/MTHPA were phase-separation crosslinking systems and most of PPC could react with MTHPA or the epoxy group. The toughness of cured resins was reinforced by the addition of PPC. The optimum mechanical properties and toughness for cured resins of PPC/EP/MTHPA corresponded to the system containing 20 phr PPC, which achieved a 33% increase in tensile strength and a 45% increase in the fracture toughness at no expense of the elongation of cured resins. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2457–2465, 1997  相似文献   

15.
A series of poly(R‐3‐hydroxybutyrate)/poly(ε‐caprolactone)/1,6‐hexamethylene diisocyanate‐segmented poly(ester‐urethanes), having different compositions and different block lengths, were synthesized by one‐step solution polymerization. The molecular weight of poly(R‐3‐hydroxybutyrate)‐diol, PHB‐diol, hard segments was in the range of 2100–4400 and poly(ε‐caprolactone)‐diol, PCL‐diol, soft segments in the range of 1080–5800. The materials obtained were investigated by using differential scanning calorimetry, wide angle X‐ray diffraction and mechanical measurements. All poly(ester‐urethanes) investigated were semicrystalline with Tm varying within 126–148°C. DSC results showed that Tg are shifted to higher temperature with increasing content of PHB hard segments and decreasing molecular weight of PCL soft segments. This indicates partial compatibility of the two phases. In poly(ester‐urethanes) made from PCL soft segments of molecular weight (Mn ≥ 2200), a PCL crystalline phase, in addition to the PHB crystalline phase, was observed. As for the mechanical tensile properties of poly(ester‐urethane) cast films, it was found that the ultimate strength and the elongation at the breakpoint decrease with increasing PHB hard segment content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 703–718, 2002  相似文献   

16.
Infrared spectroscopy has been used to study the hydrogen bonding conditions in a nematic liquid crystalline poly(ester amide). The results showed that the material formed interchain hydrogen bonding as a result of the inclusion of amide groups in the polymer chains. The hydrogen bonding was found to be stable in the temperature range studied (up to 150°C). However, the studies suggested that the hydrogen bond strength was weaker than in polyamide and did not appear to affect the mechanical properties of the material significantly.  相似文献   

17.
Methacrylated hyperbranched poly(amine ester)s as oligomers in radiation curing resins have a lower viscosity and a higher cure speed. Their viscosity was reduced sharply when an amount of a monomer was added or the temperature was increased. Their polymerization rate and final conversion of the double bond differ with the variation of the chemical structure of the end group, molar mass, and monomer content. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 51–57, 2001  相似文献   

18.
The blends of high molecular weight poly(propylene carbonate) (PPC) and poly(butylene succinate) (PBS) were melt blended using triphenylmethane triisocyanate (TTI) as a reactive coupling agent. TTI also serves as a compatibilizer for the blends of PPC and PBS. The blend containing 0.36 wt % TTI showed that the optimal mechanical properties were, therefore, calendared into films with different degrees of orientation. The calendering condition, degree of orientation, morphologies, mechanical properties, crystallization, and thermal behaviors of the films were investigated using wide‐angle X‐ray diffraction, scanning electron microscopy, tensile testing, and differential scanning calorimetry (DSC) techniques. The result showed that the as‐made films exhibited obvious orientation in machine direction (MD). Both tensile strength in MD and the tear strength in transverse direction (TD) increased with increasing the degree of orientation. The orientation of the film also increased the crystallinity and improved the thermal properties of the PPC/PBS blend films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

19.
BACKGROUND: Conductive polymer composites (CPCs) can be obtained by filling polymer matrices with electrically conductive particles, and have a wide variety of potential applications. In the work reported, the biodegradable polymer poly(lactic acid) (PLA) as a partially miscible blend with poly(propylene carbonate) (PPC) was used as a polymer matrix. Carbon black (CB) was used as the conducting filler. RESULTS: Fourier transform infrared spectroscopy revealed interactions between matrix and CB filler; this interaction was stronger in PPC‐blend‐CB than in PLA‐blend‐CB composites. A rheology study showed that low‐viscosity PPC could improve the fluidity of the CPCs, but decrease that of CB. With increasing CB content, the enforcement effect, storage modulus and glass transition temperature increased, but the elongation at break decreased. CPCs exhibited the lowest electrical percolation thresholds of 1.39 vol.% CB when the content of PPC in PLA‐blend‐PPC was 40 wt%. The conductivity of CPCs containing 5.33 vol.% CB and 40 wt% PPC reached 1.57 S cm?1. Scanning electron microscopy revealed that CB exhibits a preference for dispersion in the low‐viscosity phase (PPC) of the multiphase matrix. CONCLUSION: In the presence of CB, partially miscible PLA‐blend‐PPC could form multi‐percolation CPCs. Moreover, the combination of PLA and PPC with CB broadens novel application of both renewable polymers and CPCs. Copyright © 2008 Society of Chemical Industry  相似文献   

20.
The recent advances in the toughening and reinforcing methods and theories in rigid inorganic particulate (RIP)‐filled poly(propylene) (PP) composites have been reviewed. Studies have shown that under given conditions, in addition to the obvious increase of modulus, an obvious brittle–ductile transition also appears in these composites. The key to toughening a polymer is the role that inclusions can play as agents that (1) induce extensive plastic deformation following the interfacial debonding between the inclusion itself and the matrix, (2) induce shear yielding of the matrix, and (3) terminate the propagation of cracks. The main factors with regard to reinforcing mechanisms are how to enhance the interfacial bonding between the particles and the matrix and how to improve the dispersion of inclusions in the matrix. The major theories interpreting the toughening mechanisms of polymer–RIP composites include micro‐voiding theory, damage competition theory, shear yielding theory, etc. It is necessary to form a soft shell/hard core structure to simultaneously toughen and reinforce polymers. Therefore, RIPs should be encapsulated with an elastic thin layer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1547–1555, 2002  相似文献   

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