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1.
Poly [2-(cinnamoyloxy)ethyl methacrylate-co-octamethacryl-POSS] nanocomposites were synthesized from octamethacryl-POSS and 2-(cinnamoyloxy)ethyl methacrylate (CEM) by free radical polymerization. The chemical structures and morphologies of these nanocomposites were determined by FTIR, 29Si NMR, energy-dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM) techniques. The XRD data showed that the materials were amorphous in nature, indicating that POSS formed an aggregate instead of a crystalline form in the polymer matrix. The POSS-CEM nanocomposites exhibited high thermal stability. Excitation and emission of the CEM-incorporated POSS nanocomposites, studied in the solid state, exhibited blue emission with CIE (x, 0.178; y, 0.137) coordinates, in addition to an emission intensity that increased with increasing CEM (monomer) concentration.  相似文献   

2.
Journal of Polymer Research - The complex and incompletely understood phenomenon of shear-induced crystallization of polymers may be nowadays analysed via the in situ POM-shear stage methodology....  相似文献   

3.
Phthalates pose adverse health effects due to their propensity to leach and the most common, di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DOP), are petroleum-based. Conversely, di-esters, succinates are biobased (produced from fermentation of biomass), biodegradable, and therefore potential sustainable replacements for phthalates. A series of succinates, di-octyl succinate (DOS), di-hexyl succinate (DHS), di-butyl succinate (DBS), and di-ethyl succinate (DES), were mixed with poly(vinyl chloride) (PVC). The interaction of the plasticizer ester carbonyl with PVC shows an average −5 cm−1 shift of the carbonyl absorbance peak energy. The glass transition temperatures (T g), were monitored by differential scanning calorimetry and dynamic mechanical analyses. The T gs of DOS and DHS plasticized PVC were significantly lower than DOP plasticized PVC at a lower percent mass. On the other hand, PVC plasticized with either DBS or DES exhibited a similar trend in lowering the T g as that of DOP plasticized PVC.  相似文献   

4.
5.
以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)、二甲基二烯丙基氯化铵(DMDAAC)为单体原料,采用水溶液聚合技术制备了粉末型阳离子三元聚合物P(AM/DMC/DMDAAC)。采用红外光谱、核磁共振和热重分析对所制备阳离子聚合物进行了结构和组成表征,并利用电导率仪和布氏黏度计对其溶解性及其溶液黏度进行了测定。结果表明:合成的产物为P(AM/DMC/DMDAAC),具有良好的热稳定性和溶解性。三元聚合物的表观黏度随着聚合物质量浓度的增加先减小后增加,随剪切速率的增加而下降。在不同的外加盐溶液里,三元聚合物溶液表现出明显的反聚电解质行为。  相似文献   

6.
Poly(l-lactide) (PLLA) was successfully synthesized by ring-opening polymerization (ROP) in bulk using silver N-heterocyclic carbene (Ag–NHC) complex. The effect of reaction time, temperature and monomer/initiator ratio on polymerization process were determined. The optimum conditions were found as 130 °C, 4 h and M/I molar ratio of about 100. The polymers were characterized by FTIR, 1H-NMR, GPC and TG. High-molecular-weight PLLA (M w = 3.78 × 104, M n = 1.91 × 104, PDI = 1.97) was synthesized by the ROP of l-lactide (LLA) with bis-(N-methyl N′-dodecylimidazole) silver(I) di-bromo argentate (1a) in bulk. The effect of different N-substituted ligand groups on the polymerization was studied. The antimicrobial activity of the synthesized polymers were investigated by using minimum inhibitory concentration test against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli and Pseudomonas aeruginosa). It was observed that the synthesized polymers displayed moderate antimicrobial activity.  相似文献   

7.
Dielectric, x-ray diffraction, density, thermomechanical, and thermogravimetric studies on polyacrylonitrile (PAN), poly[acrylonitrile-(2 methacryloyloxy)ethoxytrimethylsilane] [poly(AN-2MAETMS)], and poly[acrylonitrile-(2 methacryloyloxy)propoxytrimethylsilene] [poly(AN-2MAPTMS)] copolymers have been carried out for investigating their structure. The glass transition temperature as indicated from the dielectric and thermomechanical analysis data are lower for the copolymers as compared to PAN. Crystallinity is influenced by the introduction of the silylated acrylic comonomer units but the crystalline lattice remains similar to that of PAN. The changes obseved in the various properties of these coplymers clearly suggest a more closely packed structure of poly(AN-2MAETMS) than poly(AN-2MAPTMS), and the uninterrupted PAN sequences are longer in the former. Thermal stability of copolymers has also been investigated.  相似文献   

8.
SUMMARY The crosslinked poly([2-(methacryloyloxy)ethyl]trimethyl ammonium chloride-co-acrylic acid) was tested as adsorbent for Cd(II), Hg(II), Zn(II), Pb(II), Cr(III), and U(VI) by batch equilibrium procedure. At pH 5.0 the adsorbent retained 74% (1.865 meq/g) of U(VI) with a maximum capacity of load of 2.7 meq/g (108 mg/g). The resin-U(VI) equilibrium was achieved around of 1 h which is considered adequate for a heterogeneous reaction. It showed a high selectivity for U(VI) respect to all the other metal ions both from competitive and non-competitive conditions. The recovery of the resin was over 65% by H2SO4 and Na2CO3. Received: 5 April 1999/Revised version: 14 July 1999/Accepted: 27 July 1999  相似文献   

9.
A novel graft copolymer of [2-(methacryloyloxy)ethyl] trimethylammonium chloride onto poly(vinyl alcohol) has been synthesized and it is cross-linked by glutaraldehyde for the investigation of its efficiency in removing Cr(VI) from aqueous solution. The chemical nature of the ion-exchange resin has been elucidated with the help of chemical test, Fourier transform infrared, thermo gravimetric analysis and DTA. Particle size, surface area, ion-exchange capacity, optimum pH, reaction time and temperature for Cr(VI) extraction were determined. Chromium(VI) adsorption kinetics, isotherm and thermodynamics have been studied. A plausible mechanism for chromium ion-exchange has been suggested.  相似文献   

10.
Poly(vinyl chloride)–polyol (AB)x block copolymers have been prepared by the condensation polymerization of low-molecular-weight hydroxy-terminated poly(vinyl chlorides) (PVC) and diisocyanate-capped polyester and polyether diols. The difunctional poly(vinyl chlorides) were synthesized by ozonization of commercial resin followed by metal hydride reduction. The (AB)x block copolymers, which contained 3000 or 4300 molecular weight PVC block sizes and 1000–2000 molecular weight polyol segments, had a wide range of mechanical properties, depending on overall polymer structure. Tensile strengths ranged from 7.8 to 31.5 MPa, elongations from 125% to 610% and torsional stiffness temperatures (Tf) from 25°C to ?22°C.  相似文献   

11.
The polydichlorophosphazenes were synthesized from hexachlorocyclotriphosphazenes by ring opening polymerization in the presence of AlCl3 as a catalyst. Poly[bis(ethyl salicylate)phosphazenes] (PESP) and poly[bis(ethyl salicylate diethylamino)phosphazenes] (PESDEAP) were synthesized via macromolecular substitution reactions using ethyl salicylate and (or) diethylamine as side groups. The synthesis results were proved by nuclear magnetic resonance (1H NMR, and 31P NMR) and gel permeation chromatography. In addition, the hydrolytic degradation of PESP and PESDEAP was investigated at constant temperature in neutral medium.  相似文献   

12.
The N-alkylation of 2-(N-arylamino)ethyl trimethylammonium salts with allyl chloride, benzyl chloride, epichlorohydrin, ethylene chlorohydrin and acrylonitrile was studied and the preparation of 2-(N-allyl-, -benzyl-, -2-hydroxyethyl-, 3-chloro-2-hydroxypropyl-and 2-cyanoethyl-N-arylamino)-ethyl trimethylammonium salts is described. A method is proposed for obtaining a series of differently N-substituted derivatives of these salts from the same 2-(N-arylamino)ethyl trimethylammonium salts.  相似文献   

13.
聚酰乙基苯基次膦酰乙二胺的合成与表征   总被引:1,自引:0,他引:1  
以羧乙基苯基次膦酸、乙二胺为原料,二甲苯为溶剂,合成膨胀型阻燃剂聚酰乙基苯基次膦酰乙二胺,其最适宜的工艺条件为羧乙基苯基次膦酸与乙二胺的摩尔比为1:1,在140℃下回流反应8h,产品得率为100.8%,用红外、核磁、元素分析仪、热分析仪等对产品结构进行表征,并对其阻燃性能进行了研究。  相似文献   

14.
Peiying Guo  Pingping Wu 《Polymer》2004,45(6):1885-1893
A new conjugated rigid-rod polymer, poly(benzobisoxazole divinylene) (PBODV) has been synthesized and characterized using FTIR, 1H NMR, viscometry, wide-angle X-ray diffraction, and thermogravimetric analysis. UV absorption spectroscopy and photoluminescence spectroscopy were also used to investigate the photophysical properties of these polymers in methanesulfonic acid in detail. The results show that the introduction of trans-vinylene segments into the poly(benzobisoxozale)s backbone narrowed the optical bandgap of this class of polymers. The excitation and emission spectra change significantly with the concentration both in shape and the peak positions, indicating the formation of aggregates in solution. Furthermore, electronic paramagnetic resonance studies show the intrinsic paramagnetic defects in the PBODV, which can be interpreted using a soliton-antisoliton model.  相似文献   

15.
Summary By Schotten-Baumann's esterification of poly(2-hydroxyethyl methacrylate) with 10-undecenoyl chloride a new multimonomer - poly[2-(10-undecenoyloxy)ethyl methacrylate] was prepared. Based on the results of elemental analysis, FTIR, 1H-NMR and 13C-NMR spectra, the structure of the multimonomer was proposed. The thermal properties of the multimonomer were studied by DSC and TG. The rate of disappearance of double bonds in the multimonomer during UV irradiation was examined in the solid state to obtain a crosslinked product. Received: 17 September 2001/Revised version: 5 February 2002/ Accepted: 7 March 2002  相似文献   

16.
以苯硫酚为原料,在碱性条件下与1,1-环丙基二羧酸二乙酯反应,一步制得了抗痛风药苯磺唑酮的重要中间体(2-苯硫基乙基)丙二酸二乙酯,收率为55%。本工艺将原有路线缩短一步,极大缩短了反应时间,提高了产品收率,用1H NMR和MS对产品进行了结构表征。  相似文献   

17.
The radical polymerization of the macromonomer poly(ethyleneglycol) methyl ether methacrylate with ammonium persulfate at 60°C was carried out. The polymer was completely soluble in water. Yield was 75%. The polymacromonomer was characterized by Fourier transform infrared, proton nuclear magnetic resonance (NMR), and 13C NMR spectroscopy. Mn, Mw, and the polydispersity were determined by gel permeation chromatography. The polymacromonomer showed a high thermal stability with a TDT50% of 420°C. The metal ion binding capacity of this polychelatogen with respect to different metal ions was investigated through the liquid‐phase polymer‐based retention (LPR) technique. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2929–2934, 2002  相似文献   

18.
The hydrophilic fibers based on 2-(dimethylamino)ethyl methacrylate (DMAEMA) which could remove Cr(VI) ions rapidly were prepared by UV-irradiation induced grafting of DMAEMA through pre-coating photoinitiator on the fibers and modifying with bromoethane(BE). The FTIR, FESEM, XPS, TG-DTG and contact angle spectra manifested that DMAEMA was grafted onto the surface of PP fibers and subsequently was quaternized. The maximum grafting degree (22.9 %) and exchange capacity of DMAEMA (1.2 mmol g?1) was obtained when PP fibers was immersed in BP concentration of 0.3 % for 4 h, irradiated with the DMAEMA concentration of 100 % and irradiation time of 20 min, and then was modified with BE. The modified fibers of PP-g-DMAEMA with bromoethane were proved to remove Cr(VI) and As(V) with removal rate of 97.3 % and 96.2 % within 10 min, respectively. The prepared fibers have potential application for the removal of Cr(VI) and As(V) from wastewater highly and rapidly.  相似文献   

19.
Diblock copolymers consisting of methylmethacrylate (MMA) and N-hydroxyethylacrylamide (HEAAm) polymer were successfully synthesized via direct two steps atom transfer radical polymerization (ATRP). At first, poly(methylmethacrylate) (PMMA) macroinitiators were prepared using methyl 4-(bromo-methyl) benzoate initiator and were used for synthesizing PMMA-b-PHEAAm block copolymers. PMMA homopolymers were synthesized in N,N′-dimethylformamide (DMF) using CuBr/2, 2′bipyridine catalyst system at 110 °C temperature in nitrogen atmosphere. Block copolymers were synthesized in mixture of DMF/water (8/2 v/v%) and in pure DMF in the presence of CuBr/1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA) catalyst system at 85 and 100 °C, respectively, while argon was used for deoxygenation and inert environment. Purification of block copolymers was conducted through dialysis against deionized water using a dialysis tubing (MWCO 3,500, cellulose membrane). Molecular weights of PMMA polymers (M n  = 4,400, 6,200 and 8,400 Da) were determined by size exclusion chromatography using tetrahydrofuran (THF) as eluent. The chemical structure and actual copolymer compositions were determined using elemental analysis (EA), attenuated total reflectance infrared (ATR-IR) and proton nuclear magnetic resonance (1H NMR) spectroscopic analysis. Phase separation of diblock copolymers resulting in two glass transition temperatures as detected by differential scanning calorimeter (DSC) proves their amphiphilic behavior. Thermogravimetric analysis (TGA) also showed that diblock copolymer, with two-step decomposition has higher thermal stability than PMMA.  相似文献   

20.
A series of 2-[1-(2,6-dibenzhydryl-4-chlorophenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridine ligands (L1–L5) as well as the ligand 2,6-bis[1-(2,6-dibenzhydryl-4-chloro-phenylimino)ethyl]pyridine (L6) were synthesized and reacted with FeCl2·4H2O to afford the iron(II) dichloride complexes [LFeCl2] (Fe1–Fe6). All new compounds were fully characterized by elemental and spectroscopic analysis, and the molecular structures of the complexes Fe1, Fe2 and Fe4 were determined by single-crystal X-ray diffraction, which revealed a pseudo-square-pyramidal geometry at iron. Upon activation with either MAO or MMAO, all iron pre-catalysts exhibited very high activity in ethylene polymerization with good thermal stability. To the best of our knowledge, the current system showed the highest activity amongst iron bis(imino)pyridine pre-catalysts reported to-date. The polymerization parameters were explored to determine the optimum conditions for catalytic activity, which were typically found to be 2500 eq. Al to Fe at 60 °C in the presence of MMAO, and 80 °C in the presence of MAO. The resultant polyethylene possessed a narrow molecular polydispersity index (PDI) consistent with the formation of single-site active species.  相似文献   

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