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Condensation Polymerization (condensation + polymerization)

Distribution by Scientific Domains

Polymers and Materials Science	80%
Chemistry	20%

Selected Abstracts

Synthesis of Well-Defined Rod-Coil Diblock Copolymer of Aromatic Polyether and Polyacrylonitrile by Chain-Growth Condensation Polymerization and Atom Transfer Radical Polymerization

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 8 2008
Naomi Ajioka
Abstract The synthesis of diblock copolymers of aromatic polyether and polyacrylonitrile (PAN) was conducted by chain-growth condensation polymerization (CGCP) and atom transfer radical polymerization (ATRP) from an orthogonal initiator. When CGCP for aromatic polyether was carried out from a PAN macroinitiator obtained by ATRP with an orthogonal initiator, decomposition of the PAN backbone occurred. However, when ATRP of acrylonitrile was conducted from an aromatic polyether macroinitiator obtained by CGCP followed by introduction of an ATRP initiator unit, the polymerization proceeded in a well-controlled manner to yield aromatic polyether- block -polyacrylonitrile (polyether- b -PAN) with low polydispersity. This block copolymer self-assembled in N,N -dimethylformamide to form bundle-like or spherical aggregates, depending on the length of the PAN units in the block copolymer. [source]

Synthesis of Well-Defined Hyperbranched Polyamides by Condensation Polymerization of AB2 Monomer through Changed Substituent Effects,

ANGEWANDTE CHEMIE, Issue 32 2009
Yoshihiro Ohta
Der Wechsel des Substituenteneffekts beim Übergang vom Monomer zum Polymer kann genutzt werden, um die selektive Kondensationspolymerisation eines AB2 -Monomers an einem Kernmolekül zu steuern (siehe Schema). Man erhält hochverzweigte Polyamide mit sehr niedriger Polydispersität und einem über das Monomer/Kern-Verhältnis kontrollierbaren Molekulargewicht. [source]

Multivariate monitoring of batch processes using batch-to-batch information

AICHE JOURNAL, Issue 6 2004
Jesus Flores-Cerrillo
Abstract Multiway principal component analysis (MPCA) and multiway partial-least squares (MPLS) are well-established methods for the analysis of historical data from batch processes, and for monitoring the progress of new batches. Direct measurements made on prior batches can also be incorporated into the analysis by monitoring with multiblock methods. An extension of the multiblock MPCA/MPLS approach is introduced to explicitly incorporate batch-to-batch trajectory information summarized by the scores of previous batches, while keeping all the advantages and monitoring statistics of the traditional MPCA/MPLS. However, it is shown that the advantages of using information on prior batches for analysis and monitoring are often small. Its main advantage is that it can be useful for detecting problems when monitoring new batches in the early stages of their operation., the approach and benefits are illustrated with condensation polymerization and emulsion polymerization systems, as examples. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1219,1228, 2004 [source]

Synthesis of well-defined rod-coil block copolymers containing trifluoromethylated poly(phenylene oxide)s by chain-growth condensation polymerization and atom transfer radical polymerization

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2010
Yun Jun Kim
Abstract Well-defined trifluoromethylated poly(phenylene oxide)s were synthesized via nucleophilic aromatic substitution (SNAr) reaction by a chain-growth polymerization manner. Polymerization of potassium 4-fluoro-3-(trifluoromethyl)phenolate in the presence of an appropriate initiator yielded polymers with molecular weights of ,4000 and polydispersity indices of <1.2, which were characterized by 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography. Initiating sites for atom transfer radical polymerization (ATRP) were introduced at the either side of chain ends of the poly(phenylene oxide), and used for ATRP of styrene and methyl methacrylate, yielding well-defined rod-coil block copolymers. Differential scanning calorimetry study indicated that the well-defined trifluoromethylated poly(phenylene oxide)s showed high crystallinity and were immiscible with polystyrene. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1049,1057, 2010 [source]

Synthesis and properties of amine-containing poly(arylene ether sulfone) as an anion-exchange matrix

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 23 2002
Won-Keun Son
Abstract Poly(arylene ether sulfone) (PSF), showing good thermal stability and excellent mechanical properties, was synthesized as an anion-exchange matrix. It was synthesized by the condensation polymerization between bisphenol A and 4,4,-dichlorodiphenylsulfone. 1°-Amine-containing poly(arylene ether sulfone) (1°-APSF) was synthesized by the reduction reaction of a nitrated PSF. Then, it was transferred to 3°-amine-containing poly(arylene ether sulfone) (3°-APSF) by the alkylation of the amine of 1°-APSF. The properties of PSF, 1°-APSF, and 3°-APSF were investigated by Fourier transform infrared, 1H NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The introduction of the 3°-amine group into PSF increased the glass-transition temperature but decreased thermooxidative stability. The ion-exchange capacities of 1°-APSF and 3°-APSF were shown to be 2.24 and 2.86 mequiv/g, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4281,4287, 2002 [source]

in vitro Evaluation of Biodegradable Poly(butylene succinate) as a Novel Biomaterial

MACROMOLECULAR BIOSCIENCE, Issue 5 2005
Haiyan Li
Abstract Summary: Poly(butylene succinate) (PBSU) can be easily synthesized by condensation polymerization of the starting materials of succinic acid and butan-1,4-diol. It has good degradability and possesses excellent processability. Due to these advantages, PBSU was first evaluated in the present study for its potential application as a novel biomaterial. The in vitro biocompatibility of the PBSU was evaluated by monitoring proliferation and differentiation of osteoblasts cultured on the PBSU film substrates for different periods. The results showed that the PBSU was biocompatible as the osteoblasts could proliferate and differentiate on the PBSU plates. In addition, the hydrolytic degradation behavior of the PBSU films in the phosphate-buffered saline (PBS) was also investigated and the results suggested that the PBSU degraded in the PBS solution with the same behavior as that of the degradable poly(, -hydroxyesters). In addition to the biocompatibility and hydrolytic degradation, some physical properties, including hydrophilicity, and mechanical and thermal properties of the PBSU substrates, were also determined and the results revealed that the PBSU was hydrophilic and ductile with excellent processability. The biocompatibility of the PBSU, together with the advantages of hydrolytic degradability, hydrophilicity, and excellent processability, indicated that PBSU has the potential to be used as a biomaterial for tissue repair. Alkaline phosphate activity of osteoblasts cultured on PBSU and TCPS substrates for different time periods. [source]

Synthesis of Well-Defined Rod-Coil Diblock Copolymer of Aromatic Polyether and Polyacrylonitrile by Chain-Growth Condensation Polymerization and Atom Transfer Radical Polymerization

Theoretical Derivation of the Molecular Weight Distribution of End-Capped Linear Condensation Polymers

MACROMOLECULAR THEORY AND SIMULATIONS, Issue 1 2009
Henk Knoester
Abstract End-capped, low molecular weight polymers have found numerous practical applications. By providing the end-capper molecules with specific chemical functionality, the polymer material can be equipped with a desired chemical behavior for product application or polymer processing. Using probabilistic methods, formulas are derived for calculating the target molecular weight distribution and its averages for the case of linear condensation polymerization. The formulas are generally applicable, allowing for arbitrary amounts of monofunctional monomers or end-capper molecules affecting either one or both functional groups involved in the polymerization process. [source]

Poly(ester-urethane)s synthesized using polyoxalate diols

POLYMER ENGINEERING & SCIENCE, Issue 2 2005
Hideho Tanaka
Amorphous poly(ester-urethane)s (PEUs) were synthesized by reacting polyoxalate diols (PODs), which are oligoester diols prepared from condensation polymerization of dimethyl oxalate (DMO) and alkane diols, with 4, 4,-diphenylmethane diisocyanate (MDI) and propylene diamine (PDA), a chain extender. Their structure,property relationships were studied, mainly focused on effects of molecular weight and alkylene chain length of the POD. The synthesized PEUs were buried in compost soil at 30°C and incubated to conveniently evaluate their biodegradability. Their hydrolytic characteristics were also examined, and what made poly(oxalate-urethane) (POU) biodegradable was discussed. Poly(oxalate carbonate-urethane) (POCU), which can be produced adding a polycarbonate diol (PCD) into the POD and then copolymerizing them with DMO, provided biodegradable polyurethanes with mechanical properties appropriate for practical uses. In addition, the microstructure of these copolyurethanes was characterized. POLYM. ENG. SCI., 45:163,173, 2005. © 2005 Society of Plastics Engineers. [source]

Synthesis and morphology transformation of amphiphilic diblock polyurethane copolymers in aqueous solution

POLYMER INTERNATIONAL, Issue 8 2010
Qing Miao
Abstract Amphiphilic block copolymers possess both hydrophobic and hydrophilic properties and can form versatile micellar structures in aqueous solution. The aim of the research presented was to prepare a series of non-ionic amphiphilic diblock polyurethane copolymers (PUn) based on isophorone diisocyanate, monoallyl-end-capped poly(ethylene oxide) and poly(propylene oxide) (PPO), followed by an investigation of their micellization properties and morphology transformation in aqueous solution. The PUn samples were synthesized by condensation polymerization. These polyurethanes exhibit surface tension as low as 33.7,37.0 mN m,1. There is an obvious decrease in critical micelle concentration as the hydrophobic PPO molecular weight increases. According to transmission electron microscopy, the morphology of aggregates of the copolymers can be tuned by varying the concentration in aqueous solution rather than organic solvent. For example, for PU7, large compound micelles are produced instead of vesicles. For PU17, the concentration can be used to control the size and thickness of vesicles. Vesicle size increases from 60 to 500 nm and vesicle thickness from 40 to 60 nm with concentration ranging from 0.003 to 0.03 wt%. The study shows that the copolymers in aqueous solution have excellent surface activities. In addition, they can self-assemble into large compound micelles or vesicles at certain concentrations. Moreover, the synthesis method described allows one to obtain a desired morphology of aggregates by adjusting the composition of hydrophilic and hydrophobic segments, which provides a novel and simple way to obtain particles on the nanometer scale. Copyright © 2010 Society of Chemical Industry [source]

Synthesis and characterization of poly(butylene succinate)/epoxy group functionalized organoclay

POLYMER INTERNATIONAL, Issue 9 2007
Guang-Xin Chen
Abstract Poly(butylene succinate) (PBS)/clay nanocomposites were prepared by condensation polymerization of 1,4-butanediol and succinic acid in the presence of an organoclay containing epoxy groups (TFC) and titanium(IV) butoxide as a catalyst. The intercalation and exfoliation of the clay layers in the resulting composite were examined using X-ray scattering and transmission electron microscopy. The role of the epoxy groups of TFC was investigated for the improvement of the morphology of the composites. The silicate layers in the composite were exfoliated to a greater extent as the epoxy content of TFC was increased from 0.245 to 0.359 mmol g,1, while only intercalated morphology was obtained when no epoxy was present. The improved morphologies were attributed to the enhanced interfacial interactions between PBS and TFC through a chemical reaction of the epoxy groups with the end groups of the PBS. The nonisothermal crystallization process of the composites as well as that of neat PBS is well represented by the Avrami equation as modified by Jeziorny [Jeziorny A, Polymer19:1142 (1978)]. The crystallization of the composite took place faster as the epoxy content of the clay increased, due to the more effective nucleation of the well-dispersed TFC layers. Copyright © 2007 Society of Chemical Industry [source]

Synthesis, thermal, and rheological properties of poly(trimethylene terephthalate)/BaSO4 nanocomposites

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 10 2009
Chenguang Yao
Abstract A novel method was developed for fabricating poly(trimethylene terephthalate) (PTT)/BaSO4 nanocomposites using in situ polymerization. A nano-BaSO4 suspension was prepared by reacting H2SO4 with Ba(OH)2 in 1,3-propanediol (PDO). The mean size of original nano-BaSO4 is 15,23,nm. PTT matrix was synthesized by condensation polymerization of bis(3-hydroxypropyl terephthalate) after the completion of transesterification of dimethyl terephthalate (DMT) with PDO. It was found that the addition of BaSO4 had little influence on the synthesis of PTT. The properties of nanocomposites with a wide range of BaSO4 fraction were systematically studied. The morphologies of the composites were investigated by transmission electron microscopy (TEM), which showed that agglomerate structures did not form until BaSO4 content higher than 8,wt%. The thermal properties of the nanocomposites were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results revealed that the triple endothermic melting phenomenon is only observed for the nanocomposites which contained 4,wt% BaSO4, other samples exhibit double endothermic melting. These results indicated that nano-BaSO4 could induce a microcrystal to form more perfect morphology and restrain the formation of much thicker lamellar crystallinity, that is, nano-BaSO4 could induce the formation of more uniform crystallinity. Besides, the crystallization ability of the composites was greatly improved by loading nano-BaSO4. The TGA results suggested that nano-BaSO4 slightly increased the maximum-decomposing-rate temperature 1 (Tmax1), but markedly increased the maximum-decomposing-rate temperature 2 (Tmax2). Furthermore, the steady-state shear behavior of samples was investigated by a parallel-plate rheometer. The storage modulus (G') and loss modulus (G") curves shifted to higher modulus upon addition of 2,16,wt% of nano-BaSO4. All of the samples investigated exhibited the expected shear-thinning behavior. Proper contents of nano-BaSO4 would decrease the shear viscosity of nanocomposites, whereas superfluous amounts would greatly increase the viscosity of nanocomposites and the composites which loaded 8,wt% nano-BaSO4 revealed an equivalent shear viscosity compared to pure PTT. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Synthesis of poly(cystine bisamide)-PEG block copolymers grafted with 1-(3-aminopropyl)imidazole and their phase transition behaviors

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11 2008
Byung Suk Jin
Abstract New biodegradable and pH-sensitive block copolymers were prepared by grafting 1-(3-aminopropyl) imidazole onto a backbone polymer formed via condensation polymerization between l -cystine and EDTA-dianhydride. The copolymer with a graft ratio of 79% exhibited a good buffering capacity and pH sensitivity. These are attributed to protonation,deprotonation of the imidazole ring at around pH 7. The copolymers with less imidazole content did not show any apparent responses to changes in pH. The particle size of the copolymer aggregate formed under basic conditions was around 200,nm and increased with decreasing pH. The critical aggregation values at pH 6.0 and 8.0, derived from the changes of intensity ratios (I1/I3) in the emission spectrums of pyrene, were approximately 0.17 and 0.05,mg/ml, respectively. The surface charge of the aggregates increased with the decreasing pH as a result of the increase in protonation of imidazole and the tertiary amine in the polymer chain. The microviscosity of hydrophobic domains was estimated using 1,6-diphenyl-1,3,5-hexatriene. The decrease of the anisotropy value under acidic conditions reflects a disruption of hydrophobic interaction. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Synthesis, static, and dynamic light scattering studies of soluble aromatic polyamide

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2008
Sonia Zulfiqar
Abstract Aromatic polyamide was synthesized via condensation polymerization of 4-aminophenyl sulfone (APS) with isophthaloyl chloride (IPC) using N,N -dimethyl acetamide (DMAc) as a solvent under anhydrous conditions. The purified aramid was studied by laser light scattering (LLS) in dimethyl sulfoxide (DMSO), a thermodynamically good solvent at 20°C. Static and dynamic light scattering studies permitted to determine the weight average molecular weight , radius of gyration , second virial coefficient A2, the hydrodynamic radius RH, and the diffusion coefficient D. Light scattering experiments were conducted at five concentrations ranging from 0.27 to 2.5,g/L. LLS measurement is also a very useful technique to study the aggregation or association in a polymer system as long as the large "clusters" are reasonably stable in time. The intensity autocorrelation function obtained on the quasi-elastically scattered light showed a simple diffusive relaxation mode. The ratio of radius of gyration to the hydrodynamic radius, i.e. ,,,1.3 indicates that the polyamide chain has coil conformation in DMSO at 20°C. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Hydrothermal carbonization of biomass: A summary and discussion of chemical mechanisms for process engineering

BIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2010
Axel Funke
Abstract Hydrothermal carbonization can be defined as combined dehydration and decarboxy lation of a fuel to raise its carbon content with the aim of achieving a higher calorific value. It is realized by applying elevated temperatures (180,220°C) to biomass in a suspension with water under saturated pressure for several hours. With this conversion process, a lignite-like, easy to handle fuel with well-defined properties can be created from biomass residues, even with high moisture content. Thus it may contribute to a wider application of biomass for energetic purposes. Although hydrothermal carbonization has been known for nearly a century, it has received little attention in current biomass conversion research. This review summarizes knowledge about the chemical nature of this process from a process design point of view. Reaction mechanisms of hydrolysis, dehydration, decarboxylation, aromatization, and condensation polymerization are discussed and evaluated to describe important operational parameters qualitatively. The results are used to derive fundamental process design improvements. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd [source]