bluuebunny/crossref_metadata_2025_split huggingface dataset:
Miscibility of poly(2‐chloroethyl methacrylate) with various polymethacrylates
Authors: Neo M. K. , Lee S. Y. , Goh S. H. 
Published: April 2003

AbstractThe miscibility behavior of poly(2‐chloroethyl methacrylate) (PCEMA) with various polymethacrylates was investigated by differential scanning calorimetry. PCEMA is miscible with poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), and poly(tetrahydrofurfuryl methacrylate) (PTHFMA), but is immiscible with poly(n‐propyl methacrylate), poly(isopropyl methacrylate), poly(n‐butyl methacrylate), and poly(cyclohexyl methacrylate). PCEMA/PEMA blends showed lower critical solution temperature (LCST) behavior but PCEMA/PMMA and PCEMA/PTHFMA blends degraded before phase separation could be induced. The miscibility behavior of PCEMA is similar to that of a chlorinated polymer.
Effects of some phenylethynylsilicon compounds on heat‐curable silicone rubber. I. 1,3‐bis(methylphenylethynylvinyl)disiloxane
Authors: Feng Shengyu , Du Zuodong 
Published: April 2003

AbstractWe have investigated the effects of 1,3‐bis (methylphenylethynylvinyl) disiloxane (BMPVDS) as crosslinker on heat‐curable silicone rubber and measured sol fractions and crosslink density of vulcanizates by benzene‐extract and toluene‐swelling methods, respectively. The experimental results show that, adding suitable amounts of BMPVDS, the vulcanizates exhibited rather fine mechanical properties. The tear strength of some vulcanizates could reach as high as 60.31 kN/m, the tensile strength 13.46 MPa, and the modulus at 100% extension 2.45 MPa, and the permanent deformation is rather low. BMPVDS is also a good curing retarder of hydrosilation curing silicone rubber. When adding 0.08 part of BMPVDS or more, the stocks can store at 20 ± 1°C more than 50 days without curing.
Removal of Escherichia coli from water by systems based on insoluble polystyrene–poly(ethylene glycol)s, –polyethylenimines, and –polyethylenepolyamines quaternized
Authors: Tashiro Tatsuo 
Published: April 2003

AbstractInsoluble polymers adsorbing bacterial cells were prepared by reactions of chloromethylated, divinylbenzene crosslinked polystyrene (CMPS) beads with poly(ethylene glycol) 600 (PEG600), PEG monolaurate (PEGLE), polyethylenimines (PEIs, MW = ca. 300. 600. and 1200, referred to as PEI300, PEI600, and PEI1200, respectively), as well as ethylenediamine (ED) and tetraethylenepentamine (TEP) as polyethylenepolyamines. CMPS‐ED and CMPS‐TEP were further quaternized with 1‐iodooctane (IO) and 1‐iodododecane (IDD), respectively. These polymers were brought into contact with Escherichia coli by stirring in sterilized, distilled, and deionized water. Although CMPS‐PEG and CMPS‐PEGLE did not adsorb the cells, they caused a decrease in the number of viable cells. The decrease seemed to result from the bactericidal action of substances leached from the polymers. CMPS‐PEI300, CMPS‐PEI600, and CMPS‐PEI1200, CMPS‐ED‐IO, and CMPS‐TEP‐IDD caused a decrease in the viable cell number by adsorption of the cells to their surfaces. It was observed with a scanning electron microscope that the cells were present on the surfaces of CMPS‐PEI600 beads. The decrease coefficient for decrease in viable cell number of E. coli caused by the polymer increased with nitrogen content of the polymer. The adhesion of the cells to CMPS‐PEI300, CMPS‐PEI600, and CMPS‐PEI1200, CMPS‐ED‐IO, and CMPS‐TEP‐IDD was due mainly to electrostatic interaction between them.
The structure and properties of drawn blends of polyethylene and polypropylene
Authors: Gallagher G. A. , Jakeways R. , Ward I. M. 
Published: April 2003

AbstractA series of highly oriented tapes has been prepared from a blend consisting of equal proportions of polyethylene and polypropylene. The mechanical properties and the structure and morphology of the samples have been investigated using DSC, optical microscopy, and wide angle and small angle diffraction, including measurements of crystal strain on samples under stress. It has been confirmed that the blend is incompatible, and a structural model has been proposed which is consistent with the observation that the polyethylene and polypropylene components act essentially independently in their response to external macroscopic stress.
Plasma deposition modified nylon 4 membranes for hemodialysis
Authors: Lai J. Y. , Shih C. Y. , Tsai S. M. 
Published: April 2003

AbstractThe purpose of this research is to prepare high solute permeability membranes for hemodialysis by plasma depositing hydrophilic monomers onto chemically treated or O2 plasma etched Nylon 4 substrate. The factors that affect the performances of membranes, such as deposition conditions and chemical or plasma etching conditions, were studied. The monomers used in this study were 1‐vinyl‐2‐pyrrolidone (VP), 2‐Hydroxyethyl methacrylate (HEMA), and Methyl methacrylate (MMA). The permeabilities of NaCl, urea, vitamin B12, and albumin were measured, as were the water content, hydration, diffusivity, partition coefficient, and protein adsorption ratio of fibrinogen to albumin by membrane surface of plasma deposited membranes.The permeabilities of NaCl, urea, vitamin B12, and albumin of HEMA 5 w‐1 h plasma deposited onto chemical treated Nylon 4 membranes were 2.896 ± 0.192, 3.301 ± 0.325, 0.010 ± 0.007, and 0.000 x 10−5 cm2/min, respectively. The mole ratio of adsorbed fibrinogen to adsorbed albumin (F/A) is 0.26 ± 0.05, which is much lower than that of the pure Nylon 4 membrane (0.94 ± 0.06) and the Gambro® membrane (0.90 ± 0.15). The HEMA deposited membrane possesses the highest feasibility as hemodialysis material among those plasma deposited membranes considered.
Ultrasonic investigation of some rubber blends
Authors: Sidkey M. A. , El Fattah A. M. Abd , Yehia A. A. , El All N. S. Abd 
Published: April 2003

AbstractCompression ultrasonic velocity, longitudinal ultrasonic absorption, and heat of mixing for NR‐BR, NR, NBR, and NR‐IIR rubber blends were measured. Results show the applicability of examining the compatibility degree by using longitudinal ultrasonic absorption techniques. Results showed that NR‐BR blends are compatible, whereas NR‐NBR and NR‐IIR blends are semicompatible and incompatible, respectively.
Interactions between polymeric containers and their contained solution: Modeling of polymer‐water solute partitioning via coupled solvent‐water partition coefficients
Authors: Jenke Dennis R. , Kenley Richard A. , Hayward Denise S. 
Published: April 2003

AbstractThe interaction between several polymeric materials, typical of those that have application as parenteral product containers, and 16 marker solutes was evaluated. Polymers used included polypropylene, polyvinyl chloride, ethylenevinyl acetate, an olefin rubber, a polyester ether block copolymer, and various composites of these materials. In addition, the partitioning of solutes between two common PVC plasticizers (dioctyl phthalate and butyryl hexyl citrate) and water was also examined. Correlation between equilibrium interaction constants (Eb) (which describe the equilibrium distribution of a solute between contacting polymer and solution phases) and solute octanol‐water (Po‐w) or hexane‐water (Ph‐w) partition coefficients were in general poor for all materials studied. However, a bivariate linear interaction model relating Eb to both partition coefficients:

effectively mimicked the interaction behavior of all materials evaluated. The utilization of the developed models to facilitate container compatability assessments is discussed. In addition, the use of a critical ratio of binding constants for a pair of solutes is introduced as a means of qualitatively assessing the effectiveness of a particular solvent as a polymer model.
Synthesis and characterization of ethyl methacrylate‐acrylamide copolymers
Authors: Srinivasulu B. , Rao P. Raghunath , Sundaram E. V. 
Published: April 2003

AbstractFree radical copolymerization of ethyl methacrylate (EMA) and acrylamide (AA) was carried out in the presence of 2,2′‐azobisisobutyronitrile (AIBN) in dimethyl formamide (DMF) at 60°C. The percentage composition of the copolymers were established by elemental analysis. The copolymerization reactivity ratios were determined by both Fineman‐Ross (F‐R) and Kelen‐Tudos (K‐T) methods. The copolymers were characterized by IR, 1H‐NMR, thermal, and dielectric studies. Glass transition temperatures (Tg) have been determined by DSC. The solubility parameter of this copolymer was evaluated by studying the intrinsic viscosity in different solvents.
Polyimides synthesized from siloxane‐equilibrated 1,3‐bis (3,4‐dicarboxyphenyl)‐1,1,3,3‐tetramethyldisiloxane dianhydride
Authors: Nye S. A. , Swint S. A. 
Published: April 2003

AbstractSilicone polyimides were made with siloxane‐equilibrated 1,3‐bis (3,4‐dicarboxyphenyl) ‐ 1,1,3,3‐tetramethyldisiloxane dianhydride (PADS) as the soft portion and [(1‐methylethylidene) bis (4,1‐phenyleneoxy)] bis‐1,3‐isobenzofurandione (BPADA) as the hard portion in combination with either para or meta‐phenylene diamine. The silicone polyimides were made with varying siloxane chain lengths and with varying overall weight percent silicone. There were linear correlations between these variables and flexural modulus, percent elongation at break, and cut‐through temperature. Glass transition temperatures were evaluated by dynamic mechanical analysis and the thermal stabilities were determined to be greater than 400°C by thermal gravimetric analysis. Melt viscosities were determined on the various copolymers and demonstrated a correlation between type of amine used, siloxane chain length, and overall weight percent silicone.
Catalytic chain transfer in polymerization of methyl methacrylate. II. Continuous synthesis and purification of macromer
Authors: Suddaby K. G. , Sanayei R. Amin , Rudin A. , O'driscoll K. F. 
Published: April 2003

AbstractA continuous process for the production of kilogram quantities of poly(methyl methacrylate) macromers using catalytic chain transfer agents is described. The macromers are synthesized in a tubular reactor and isolated from unreacted monomer using a twin‐screw extruder. Three concentrations of catalytic chain transfer agent were used and macromers of Mn = 480, 752, and 1334 were made. The behavior of the tubular reactor runs over time was determined by monitoring both conversion and the molecular weight distribution of the macromers in the reactor effluent. Trends in this behavior with respect to time and catalytic chain transfer agent concentration are discussed. Experimental details are given and the efficiency of the devolatilization of the monomer from the reactor effluent using a twinscrew extruder is examined.
Synthesis and characterization of poly(methyl methacrylate‐co‐2‐hydroxypropyl methacrylate)‐graft‐polyoxyethylene
Authors: Jialanella Gary L. , Piirma Irja 
Published: April 2003

AbstractThis study involved the synthesis and characterization of an amphipathic graft copolymer, poly(methyl methacrylate‐co‐2‐hydroxypropyl methacrylate)‐graft‐polyoxyethylene. This amphipathic graft copolymer was synthesized utilizing a “grafting‐onto” technique in which α‐hydroxy‐ω‐methoxypolyoxyethylene was reacted with prepolymerized poly(methyl methacrylate‐co‐glycidyl methacrylate). Proof of copolymer formation was illustrated using water solubility, GPC, FTIR spectroscopy, and 13C‐NMR spectroscopy. In all cases, proof of copolymer formation is demonstrated unequivocally.
Phenyl acrylates and divinyl benzene cross‐linked copolymers as basic novel supports: Synthesis and characterization
Authors: Narasimhaswamy T. , Reddy B. S. R. 
Published: April 2003

AbstractSuspension Copolymerization of glycidyl methacrylate (GMA), phenyl methacrylate (PhMA), 2,4,6‐tribromophenyl acrylate (TBPA), and 4‐acetylphenyl acrylate (APA) with divinyl benzene (DVB) was carried out at 80 ± 1°C in aqueous medium, as basic supports for possible applications in polymer‐supported chemistry. The resulting copolymer heads were characterized with various techniques. The identification of monomers in the copolymer was attempted using FTIR and 13C‐CP/MAS‐NMR spectroscopic techniques. The optical and scanning electron microscopic methods were used to study the shape, size, and surface morphology of the beaded copolymers. The particle‐size distribution was measured, and the average particle size of the particulate copolymers were carried out using a Malvern particle‐size analyzer. The decomposition temperatures and energy of activation involved in the thermal degradation were studied with thermogravimetry. The solvent imbibition of the polymer supports in various solvents was carried out with a centrifuge method.
Synthesis and evaluation of hexafluorodimethylcarbinol functionalized polymers as microsensor coatings
Authors: Snow A. W. , Sprague L. G. , Soulen R. L. , Grate J. W. , Wohltjen H. 
Published: April 2003

AbstractPolystyrenes, polyacrylates, and poly(3,4‐isoprenes) incorporating the hexafluorodimethylcarbinol functionality have been synthesized, characterized, and tested as microsensor coatings on a surface acoustic wave (SAW) device for dimethyl methylphosphonate (DMMP) vapor absorption sensitivity. The syntheses involved monomer functionalization and polymerization or hexafluoroacetone reaction with preformed polymer. All fluoroalcohol functionalized polymer coatings displayed sub parts per million level sensitivity with the slope of the absorption isotherm steepest at low DMMP concentrations. The order of sensitivity for the isomeric polystyrene fluoroalcohols (meta > para ≫ ortho) paralleled that of the relative free hydroxyl to hydrogen‐bonded hydroxyl content. Strong hydrogen bonding between the fluoroalcohol polymers and DMMP vapor was observed by IR spectroscopy. Acylation of the fluoroalcohol group markedly reduced the DMMP sensitivity.
Textures of ethyl cellulose–dichloroacetic acid mesomorphic solution
Authors: Huang Y. , Zhou J. Y. 
Published: April 2003

AbstractTextures of the ethyl cellulose (EC)‐dichloroacetic acid (DCA) mesomorphic solution were studied systematically by polarizing microscopy and small‐angle light scattering. It was found that with increasing polymer concentration, the mesophase could show a disklike texture, an oil streak texture, a pseudoisotropic texture, and an iridescent planar texture. Within the mesophase the ordering degree is different in different zones. The phase transition between anisotropic and isotropic phases could also be accomplished by changing temperature. With increasing temperature the mesophase with the lower degree of order could first transform to the isotropic phase and the phase transition from an anisotropic phase with a higher degree of order to the isotropic one could take place only at the higher temperature. A disklike texture was also observed during the phase transition between the anisotropic and isotropic phases when the solution was heated and it was probably a basic texture in polymer cholesteric liquid crystals.
Polyethylene–poly(methacrylic acid‐co‐divinylbenzene) interpolymer‐type carboxylic membranes
Authors: Wycisk Ryszard , Trochimczuk Witold M. 
Published: April 2003

AbstractA short review of the methods of preparation of carboxylic membranes was presented. Details were given on the preparation procedure of polyethylene‐poly(methacrylic acid‐co‐divinylbenzene) PE‐poly(MA‐co‐DVB) interpolymer‐type carboxylic membranes and on the optimization of the procedure. The membranes were synthesized by swelling PE in sheet form in a mixture of MA, DVB, and benzoyl peroxide (BP), with subsequent heating of the gel to interpolymerize the monomers. The dependence of ion exchange capacity, swelling, resistivity, and permeability on poly(MA‐co‐DVB) and DVB contents were investigated. With the use of an electron microscope a domain‐type morphology was observed at low poly(MA‐co‐DVB) and DVB contents. Crystallinity of PE was not influenced by the presence of poly(MA‐co‐DVB).
Nylon 4/PVA blend membrane for dialysis
Authors: Lai J. Y. , Chen Y. C. , Hsu K. Y. 
Published: April 2003

AbstractTo improve the hydrophilicity and enhance the transport flux of nylon 4 membrane for dialysis, this study attempts to utilize blending nylon 4 with poly(vinyl alcohol) (PVA). The instability of PVA in water can be obtained more easily than by other methods, such as chemical, γ‐ray irradiated crosslinking, or high‐temperature treatment used by previous researchers. The effects of maturation time of the casting solution, nylon 4/PVA ratios, and casting solvent compositions on esterification of PVA, salt permeability, water content, partition coefficient, diffusivity, and mechanical strength of membrances are studied. The membrane, prepared by casting solution of nylon 4/PVA = 9/1 wt % formic acid with 24‐h maturation time, possesses permeabilities of NaCl and urea, 33.14 and 19.67 × 10−5 cm2/min, respectively.
Amines release from schiff bases polymers and diffusion from dosage forms with eudragit RL in acidic medium
Authors: Chafi Nafa , Kolli Malika , Vergnaud Jean‐Maurice , Montheard Jean‐Pierre 
Published: April 2003

AbstractChloromethylstyrene 1 (mixture meta and para; 60/40) can be oxydized in corresponding aldehyde 2. Vinylbenzaldehyde 2 reacts with primary amines such as aniline, benzylamine, 2‐phenylethylamine, 3‐phenylpropylamine, and 2‐aminopyridin to give Schiff bases that are polymerized in bulk with a radical initiator. Poly(vinyl benzaldehyde) 6 prepared from corresponding monomer 2 also reacts with primary amines to give polymeric Schiff bases. Hydrolyses of these polymeric imines have been carried out either in heterogeneous acidic medium or basic heterogeneous medium; a suitable percentage of amines has been released after some hours. Finally, a study of hydrolysis and of diffusion of released amines in a dosage form (Eudragit RL) has been also carried out with some polymeric Schiff bases.
Curing reaction and product properties of polysulfones terminated with active functional groups
Authors: Jin Shijiu , Yee Albert F. 
Published: April 2003

AbstractThe curing processes of maleimide‐terminated polyether sulfone oligomers (Mn from 1100 to 3000) and ethynyl‐terminated polysulfone prepolymers (Mn from 2600 to 12000) were investigated by means of DSC. The initial temperature of cure reaction is increased, and the apparent activation energy Ea of cure reaction is decreased as the Mn of the uncured prepolymer increases. On the basis of the Tg changes during the curing process, the kinetics of cure is proposed to be similar to a stepwise reaction, although the curing reaction is believed to proceed via a free radical chain mechanism. In this proposed reaction some initial reaction products with many branches and one remaining active functional group are formed first. The more these products occur, the more likely they can interreact to form a network. During the curing process the mobility of the active end group is restricted by the rigid polysulfone chain. Therefore, the reaction is mainly controlled by the movement of polymer, i.e., by the kinetics of diffusion. Films of these cured polymers were made by casting from solution. Their β relaxation peaks at low temperatures were examined by dielectric and dynamic mechanical measurements. The films made of the prepolymer with Mn > 3000 are flexible and foldable.
Syntheses and properties of polymers that undergo no shrinkage on cross‐linking by self‐catalyst
Authors: Tagoshi Hirotaka , Endo Takeshi 
Published: April 2003

AbstractThe polymers containing spiroorthoester and benzyl sulfonium salt moieties were prepared by the ternary radical polymerization of unsaturated spiroorthoester 2‐methylene‐1,4,6‐trioxaspiro [4.6] undecane (1) or 2‐methylene‐9‐methyl‐1,4,6‐trioxaspiro [4.5] decane (2) with vinyl benzyl sulfonium salt (VBS+SbF−6, 3) and vinyl monomers (acrylonitrile or methyl acrylate). The obtained ternary copolymers such as PI, PII, PIII, and PIV underwent curing over 75°C by self‐catalyst to obtain the corresponding gelled polymers, with expansion or only slight shrinkage on curing.
Dynamic mechanical analysis of tropical wood–polymer composites
Authors: Yap M. G. S. , Que Y. T. , Chia L. H. L. 
Published: April 2003

AbstractWood–polymer composites (WPC) of Geronggang (GE; Cratoxylon arborescens), a light tropical hardwood, impregnated with methyl methacrylate (MMA) and styrene‐co‐acrylonitrile (3 : 2; STAN), were prepared by in situ polymerization using γ radiation or catalystheat treatment. The dynamic flexural storage modulus, E′, for oven‐dried GE, moist GE, and GE–MMA and GE–STAN composites decreased with increasing temperature. The percentage decreases for GE with 10 and 16.5% moisture contents were 74.5 and 98.2%, respectively, which were higher than those for GE and GE composites, which ranged between 40 and 50%. The impregnated polymers were not as effective as water in acting as plasticizers, due to their nonpolar nature and much higher molecular weights. The α‐transition peaks for moist GE and GE composites were more distinct and were shifted to lower temperatures than those for oven‐dried GE. The values ranged between 75 and 150°C for moist GE and between 102 and 170°C for the GE composites. The α‐transitions of the catalyst–heat‐treated GE composites were lower than that of the radiation‐induced counterparts. GE–STAN composites were also observed to have lower α‐transition temperatures than those for GE–MMA for the respective treatment process, which seems to suggest that STAN interacted to a greater extent with cell wall components than did MMA.
Cross‐linking decrystallized and partially acetylated cotton yarn with dimethylol–dihydroxy–ethylene–urea
Authors: Varadarajan P. V. , Nachane Nayana D. , Sitaram M. S. , Patil N. B. 
Published: April 2003

AbstractEasy‐care finishing of cotton fabrics invariably results in the loss of mechanical properties of the fabrics. There have been many attempts from time to time by different workers to reduce the above loss in the mechanical properties. But the problem is yet to be resolved satisfactory. As the uniform distribution of cross‐links in the resin‐finished structure of cellulose is the key for achieving a better balance of mechanical properties, the present work aims at a suitable modification of the cellulose matrix to achieve the goal. The paper reports the mechanical properties of the modified and cross‐linked cotton yarn. The cross‐linked samples of the modification treatment involving swelling the yarn at normal stretch with 20% NaOH and partially acetylating without washing off the alkali have displayed higher tenacity, elongation, and toughness, with better easy‐care properties as compared to the control.