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Synthesis Of Graft Copolymer Of Syndiotactic Polystyrene Co 4 Methylstyrene With Polybutadiene Via Copolymerization Between Styrene And 4 Methylstyrene
Download Synthesis Of Graft Copolymer Of Syndiotactic Polystyrene Co 4 Methylstyrene With Polybutadiene Via Copolymerization Between Styrene And 4 Methylstyrene full books in PDF, epub, and Kindle. Read online Synthesis Of Graft Copolymer Of Syndiotactic Polystyrene Co 4 Methylstyrene With Polybutadiene Via Copolymerization Between Styrene And 4 Methylstyrene ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Synthesis of Graft Copolymer of Syndiotactic Poly(styrene-co-4-methylstyrene) with Polybutadiene Via Copolymerization Between (styrene and 4-methylstyrene) by : Nathinee Srinate
Download or read book Synthesis of Graft Copolymer of Syndiotactic Poly(styrene-co-4-methylstyrene) with Polybutadiene Via Copolymerization Between (styrene and 4-methylstyrene) written by Nathinee Srinate and published by . This book was released on 2005 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Maro Polymer Notes written by and published by . This book was released on 1997 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Syndiotactic Polystyrene by : Jürgen Schellenberg
Download or read book Syndiotactic Polystyrene written by Jürgen Schellenberg and published by John Wiley & Sons. This book was released on 2009-10-29 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: Syndiotactic Polystyrene (SPS), synthesized in a laboratory for the first time in 1985, has become commercialized in a very short time, with wide acceptance on the global plastics market. Written by leading experts from academia and industry from all over the world, Syndiotactic Polystyrene offers a comprehensive review of all aspects of SPS of interest to both science and industry, from preparation and properties to applications. This essential reference to SPS covers: The preparation of syndiotactic polystyrene by half-metallocenes and other transition metal catalysts The structure and fundamental properties, especially morphology and crystallization and solution behavior The commercial process for SPS manufacturing Properties, processing, and applications of syndiotactic polystyrenes Polymers based on syndiotactic polystyrenes, for example, by functionalization and modification, and nanocomposites Ideal for polymer chemists, physicists, plastics engineers, materials scientists, and all those dealing with plastics manufacturing and processing, this important resource provides the information one needs to compare, select, and integrate an appropriate materials solution for industrial use or research.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis and Characterization of Graft Copolymers Poly(isoprene-g-styrene) of High Molecular Weight by a Combination of Anionic Polymerization and Emulsion Polymerization by :
Download or read book Synthesis and Characterization of Graft Copolymers Poly(isoprene-g-styrene) of High Molecular Weight by a Combination of Anionic Polymerization and Emulsion Polymerization written by and published by . This book was released on 2015 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, high molecular weight "comb-shaped" graft copolymers, poly(isoprene-g-styrene), with polyisoprene as the backbone and polystyrene as side chains, were synthesized via free radical emulsion polymerization by copolymerization of isoprene with a polystyrene macromonomer synthesized using anionic polymerization. A small amount of toluene was used in order to successfully disperse the macromonomer. Both a redox and thermal initiation system were used in the emulsion polymerization, and the latex particle size and distribution were investigated by dynamic light scattering. The structural characteristics of the macromonomer and comb graft copolymers were investigated through use of size exclusion chromatography, spectroscopy, microscopy, thermal analysis, and rheology. While the macromonomer was successfully copolymerized to obtain the desired multigraft copolymers, small amounts of unreacted macromonomer remained in the products, reflecting its reduced reactivity due to steric effects. Nevertheless, the multigraft copolymers obtained were very high in molecular weight (5-12 × 105 g/mol) and up to 10 branches per chain, on average, could be incorporated. A material incorporating 29 wt% polystyrene exhibits a disordered microphase separated morphology and elastomeric properties. As a result, these materials show promise as new, highly tunable, and potentially low cost thermoplastic elastomers.
Book Synopsis Block and Graft Copolymers by : R. J. Ceresa
Download or read book Block and Graft Copolymers written by R. J. Ceresa and published by . This book was released on 1962 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Graft Copolymers by : H. A. J. Battaerd
Download or read book Graft Copolymers written by H. A. J. Battaerd and published by . This book was released on 1967 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polystyrene written by J. R. Wünsch and published by iSmithers Rapra Publishing. This book was released on 2000 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This review describes the production of styrene polymers in detail, including the synthesis of raw materials, polymerisation routes to polystyrene, production of high impact polystyrene and anionic block copolymers. The review also describes the mechanical properties of styrenic polymers, their electrical properties, and their behaviour in fire. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.
Book Synopsis Comb Graft Copolymers by : Mark G. Branch
Download or read book Comb Graft Copolymers written by Mark G. Branch and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Styryl-terminated polystyrene macromonomers have been synthesised by the anionic polymerisation of styrene. Initiation was by sec-butyl lithium; termination involved the addition of diphenylethylene prior to vinyl benzyl chloride. Characterisation of the macromonomers was performed using gel permeation chromatography (GPC) and proton nuclear magnetic resonance spectroscopy (nmr). Novel comb graft copolymers were synthesised by the copolymerisation of the macromonomer with a comonomer. The following comonomers were used: Z-vinylpyridine (Z-VP), 4- vinylpyridine (4-VP) and N-(vinylbenzyl)pyrrolidone (VBP). Graft copolymers were made with a range of compositions by varying the feed ratios of the comonomer to the macromonomer. Reactivity ratios were determined for the different graft copolymer systems and compared to the simple statistical copolymerisation of styrene with comonomer. Characterisation of the graft copolymers was performed using GPC, nmr and membrane osmometry. Micellar dispersions of the comb graft copolymers were prepared in cyclohexane, toluene and methanol. These were subsequently characterised by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Micellar behaviour was related to graft copolymer composition and structure. The graft copolymers were subsequently used as steric stabilisers in dispersion polymerisations of bis-hydroxyethyl terephthalate in high boiling aliphatic hydrocarbon, methyl methacrylate in cyclohexane, vinyl pyridine in toluene/cyclohexane and styrene in methanol. A number of parameters have been investigated including initiator, stabiliser and monomer concentrations. Graft copolymer composition and structure were shown to be important factors for the effective steric stabilisation of polymer particles in conjunction with information on surface coverage data.
Book Synopsis Block and Graft Copolymerization by : R. J. Ceresa
Download or read book Block and Graft Copolymerization written by R. J. Ceresa and published by John Wiley & Sons. This book was released on 1973 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Cellulose-Based Graft Copolymers by : Vijay Kumar Thakur
Download or read book Cellulose-Based Graft Copolymers written by Vijay Kumar Thakur and published by CRC Press. This book was released on 2015-04-23 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cellulose-Based Graft Copolymers: Structure and Chemistry discusses the synthesis, characterization, and properties of multifunctional cellulose-based graft copolymers. Presenting the contributions of accomplished experts in the field of natural cellulosic polymers, this authoritative text: Offers an overview of cutting-edge technical accomplishmen
Book Synopsis Synthesis and Characterization of Copolymers Based on 2,3,4,5,6-pentafluorostyrene by : Marta Paz Pazos
Download or read book Synthesis and Characterization of Copolymers Based on 2,3,4,5,6-pentafluorostyrene written by Marta Paz Pazos and published by . This book was released on 2005 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2,3,4,5,6-Pentafluorostyrene (PFS) was polymerized in the presence of a solution of polybutadiene (PB) in tetrahydrofuran using benzoyl peroxide as the radical initiator at 50, 60, 80 °C. The products were graft copolymers of poly(2,3,4,5,6-pentafluorostyrene) (PPFS) into PB. The copolymerizations follow typical free radical polymerization kinetics and behavior, with the rate of propagation proportional to the monomer concentration and the square root of the initiator concentration. Gel permeation chromatography (GPC) equipped with two detectors (UV and refractive index) has allowed us to determine conversion of the monomer, graft efficiency, graft ratio and graft frequency of the grafted products obtained at different temperatures and initiator concentrations, without the need of purification and/or isolation of the final graft copolymer. Conversion of the monomer and graft ratio increase and grafting frequency decreases with increasing temperature and initiator concentration. The grafting efficiencies and grafting ratios are consistent with a system that terminates mainly by combination and whose graft sites are generated by hydrogen abstraction of allylic radicals by initiator primary radicals. Pure graft copolymers were isolated by extracting unreacted PB into hexanes and PPFS homopolymer generated as a side-product into acetone. The similarity of the glass transition temperatures of the PPFS grafts and the corresponding extracted PPFS homopolymers confirms that their lengths are approximately equal. We also attempted to react PFS with PB by an ene reaction, which would result in PB modified with perfluorinated rings connected to the PB backbone through a two carbon spacer. However, we were not able to perform the modification either with PB or with model compounds. One of the reactions tested was PFS with [beta]-pinene, which resulted in the copolymerization of them. The copolymer products are composed of isolated units of [beta]-pinene randomly distributed between blocks of PFS segments, as evidenced from their copolymer reactivity ratios and their glass transitions. PFS was also copolymerized in bulk with styrene (at 70 and 25 °C), 1-vinyl naphthalene (at 70 and 25 °C) and 2-vinyl naphthalene (at 70 °C). In all the systems investigated the copolymer reactivity ratios are indicative of copolymerization with strong tendency to alternation. NMR spectroscopy shows evidence for this alternation by both new resonances and shifting of resonances present in the homopolymers. In addition, their thermal behavior is consistent with that of alternating copolymers. They exhibit only one glass transition, at a temperature greater than the weighted average of the glass transitions of the two homopolymers. The alternation tendency and thermal behavior of the copolymers are attributed to strong interactions developed between perfluorinated aromatic rings and regular aromatic hydrocarbons.
Book Synopsis Synthesis and Characterisation of Styrene-Butodiene Graft Copolymers by : D. C. Evans
Download or read book Synthesis and Characterisation of Styrene-Butodiene Graft Copolymers written by D. C. Evans and published by . This book was released on 1974 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Utilization of Atom Transfer Radical Polymerization for Synthesis of Graft Copolymer of Natural Rubber and Poly(methylmethacrylate) by : Lapporn Vayachuta
Download or read book Utilization of Atom Transfer Radical Polymerization for Synthesis of Graft Copolymer of Natural Rubber and Poly(methylmethacrylate) written by Lapporn Vayachuta and published by . This book was released on 2009 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atom Transfer Radical Polymerization (ATRP) technique was applied for synthesis of natural rubber-grafted-poly(methyl methacrylate) (NR-g-PMMA). Active sites on macromolecular chains of NR were created by fixation of bromoalkyl groups via a two-step chemical modification: partial epoxidation on unsaturated carbon-carbon bonds, followed by nucleophilic addition of a bromoalkyl-functionalized carboxylic acid on the oxirane rings of the epoxidized natural rubber (ENR) obtained. The resulting bromoalkyl-functionalized rubber was then used as macroinitiator to initiate the ATRP of methyl methacrylate (MMA) from NR chains by varying reaction conditions. The study was successively envisaged with 4-methyloct-4-ene (a model molecule of NR repeating unit), a synthetic cis-1,4-polyisoprene, and natural rubber. In the first part, the feasibility of the grafting reaction is verified by studying the ATRP of MMA from model molecules of bromoalkyl-functionalized 1,4-polyisoprene units. The model of the 1,4-polysisoprene unit, 4-methyloct-4-ene, is transformed in various models of bromoalkyl-functionalized 1,4-polyisoprene units via a chemical modification procedure carried out in two-steps: epoxidation performed with m-chloroperbenzoic acid (CPBA) followed by the addition of the bromoalkyl-functionalized carboxylic acid (2-bromopropionic acid, A1, or 2-bromo-2-methylpropionic acid, A2) on the oxirane ring formed. The addition of the acid occurs according to an SN2 mechanism with fixation of the acid group on the less substituted carbon of the oxirane ring and is competed with a secondary reaction of rearrangement of oxirane ring, leading to the formation of two allyl alcohols. The yield of the addition depends on the acidity of the carboxylic acid used. Afterwards, resulting O-(2-hydroxy-2-methyl-1-(n-propyl)pentyl)-2-bromopropionate and O-(2-hydroxy-2-methyl-1-(n-propyl)pentyl)-2-bromoisobutyrate, were used to initiate the ATRP of MMA at 90°C in toluene using Cu(I)Br complexed with a polyamine ligand. Several ligands were tested: N-(n-octyl)-2-pyridylmethanimine (NOPMI), N-(n-octadecyl)-2-pyridylmethanimine (NODPMI), and 1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA). A good control of molecular weights (SECn,M) and polydispersity indexes (PDI) were obtained with O-(2-hydroxy-2-methyl-1-(n-propyl)pentyl)-2-bromoisobutyrate as the initiator in presence of CuBr/NOPMI as catalytic system. In the second part, the synthetic cis-1,4-polyisoprene (PI) is transformed into a bromoalkyl-functionalized polyisoprene (PI-Br) macroinitiator using a two-step chemical modification procedure similar to that used for synthesis of the model. PI was partially epoxidized using CPBA in dichloromethane, and then the epoxidized PI (EPI) obtained was reacted with A2. The addition of the acid occurs according to an SN2 mechanism with fixation of the acid group on the less substituted carbon of the oxirane ring ([beta]-addition) and is competed with rearrangement reactions of oxirane rings, leading to external allyl alcohol. SECn,M and PDI of PMMA grafts were determined by Size Exclusion Chromatography after separation from the PI backbone by hydrolysis of the ester bond using trifluoroacetic acid. An internal first order kinetic plot with respect to monomer and an increase of SECn,M with MMA conversion were observed using Cu(I)Br complexed with bidentate (NOPMI and NODPMI) and tridentate (PMDETA) ligands, as catalytic systems. With bidentate ligands, the PDI of grafts is better controlled. Moreover, the control of SECn,M and PDI of PMMA grafts was affected by increasing the degree of initiating units in PI-Br. In the last part, NR is used as a starting material. It was partially epoxidized in ENR in latex medium by reaction with performic acid generated in-situ from formic acid and hydrogen peroxide, and then ENR was transformed in bromoalkyl-functionalized NR (NR-Br) by nucleophilic addition of A2 on the oxirane rings. The addition of the acid is similar to that observed during the studies performed with 4-methyloct-4-ene and PI. Resulting NR-Br was then used to initiate the graft polymerization of MMA from NR chains using normal ATRP in toluene solution and in aqueous dispersed medium, respectively. AGET-ATRP was also considered in aqueous dispersed medium to study the effect of water for further ATRP graft copolymerization studies with NR latices. By normal ATRP in toluene solution, the termination reactions by recombination decreased as MMA concentration deceased, from 30 wt% to 10 wt%. PDIs of PMMA grafts vary in range from 1.7 (at 8.1 % MMA conversion) to 2.0 (at 52.0 % MMA conversion). A better control of the SECn,M and PDI of PMMA grafts was obtained by using normal ATRP in aqueous dispersed medium, more especially when CuBr was complexed with NODPMI. In these conditions, PDIs of PMMA grafts were low (closed to 1.5 at low MMA conversion). In AGET-ATRP performed in aqueous dispersed medium, it was shown that the efficiency of graft copolymerization is affected by the concentration in ascorbic acid used as reducing agent. The chemical structures obtained were characterized by FT-IR, and by 1H and 13C NMR. The thermal properties of the graft copolymers synthesized were studied by Differential Scanning Calorimetry (DSC). The presence of two Tgs, at about -14°C and 99°C respectively, on the DSC curves when the amounts of PMMA in NR-g-PMMAs are higher than 65 wt%, shows that these materials adopt a biphasic morphology.
Book Synopsis Synthesis and Characterization of Poly(oxyethylene) Graft Copolymers on Polystyrene by : F. Candau
Download or read book Synthesis and Characterization of Poly(oxyethylene) Graft Copolymers on Polystyrene written by F. Candau and published by . This book was released on 1976 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis of Graft Copolymers Based on Poly(R-3-hydroxybutyrate) for Orthopaedic Surgery Purposes by : Sophie Nguyen
Download or read book Synthesis of Graft Copolymers Based on Poly(R-3-hydroxybutyrate) for Orthopaedic Surgery Purposes written by Sophie Nguyen and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Graft copolymers using biodegradable and biocompatible bacterial poly([ R]-3-hydroxybutyrate) blocks were synthesized and tested as biomaterial candidates for orthopaedic surgery applications. Low molecular weight poly([ R]-3-hydroxyalkanoates), namely poly([R]-3-hydroxybutyrate), poly([R]-3-hydroxyvalerate), and their copolymers poly([ R]-3-hydroxybutyrate-co-[R]-3-hydroxyvalerate), were prepared by thermal degradation in the melt at 190°C. The chemical composition of the oligomers was well-defined, featuring the same repeat unit as their high molecular weight analogues, a carboxylic acid end, and an alkenyl end mostly in the trans configuration (crotonate-type). Increase in the reaction temperature, time, or [R]-3-hydroxyvalerate content decreased the molecular weight of the products. Methacrylic macromonomers of PHB were obtained by functionalization of the oligomers at the carboxyl end, and copolymerized with methyl methacrylate. Two free radical polymerization methods were employed: conventional free radical and a controlled free radical polymerization, Atom Transfer Radical Polymerization. Kinetics of the copolymerizations were studied, and the copolymerization behavior of the comonomers was shown to change with the comonomer feed composition. This would have resulted in variable graft copolymer microstructures. Graft copolymers produced by conventional free radical copolymerization were incorporated in commercial acrylic (poly(methyl methacrylate)-based) bone cement formulations. Cements with formulations containing 6.6-6.7, and 13.5 wt.-% of PMMA-graft-PHB were prepared. The morphology of the graft copolymer particles was suggested to influence the processability of the modified cement. The cements were found rather porous, with average porosities of 13.5 to 16.9%. Nevertheless compression strengths were quite similar to those found for the reference material, pure Antibiotic SimplexRTM, and met the ASTM requirements on acrylic b" --
Book Synopsis Synthesis of Grafted Copolymers of Modified Polyacrylonitrile and Production of Fibers Based on Them by : M. P. Penkova
Download or read book Synthesis of Grafted Copolymers of Modified Polyacrylonitrile and Production of Fibers Based on Them written by M. P. Penkova and published by . This book was released on 1969 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acrylonitrile was copolymerized with a small proportion of I. The copolymer (Ia) contained 24.57 percent N, a given molecular weight 45,000-50,000, and sp. viscosity of 0.25 percent soln. in dimethylformamide (II) 0.47-0.51. The reactive NH(subscript 2) groups in I permitted Me acrylate (III) to be grafted onto it, whereas polyacrylonitrile was too inert to be used as a basis for the graft. The initiator for the grafting reaction was HVO(subscript 3) in H(subscript 2)SO(subscript 4) soln. Preliminary purification of III is done by distn. under Av. Typical conditions for the graft polymn. of III on Ia were: H(subscript2)SO(subscript 4) (1.5 moles/1.) HVO(Subscript 3) (0.04 moles/1.), vol ratio 50 to 1, 60 degrees, 1 hr., in a glass ampul under A and Ia increased in wt. by 10.80 percent. Control of the grafting was by increase in wt. and by N content. In the above example, the graft copolymer (IV) contained 22.25 percent N, which agreed well with the increase in wt. Durability is increased by 3 times by the grafting process.
