bluuebunny/crossref_metadata_2025_split huggingface dataset:
The chemistry of chromium complexes used as coupling agents in fiberglass resin laminates
Authors: Yates Paul C. , Trebilcock John W. 
Published: December 2004

AbstractThe chromium complex is chemically bonded by ion exchange with alkali cations to strongly acidic sites in the glass surface. These sites are formed by the isomorphous replacement of silicon by boron and aluminum in the network structure. Polymerized complexes are better bonding agents than monomeric ones. Specific interactions between organic groups on the chrome complex and the bonding resins also determine laminate strength and water resistance.
A new interpretation of the glass‐coupling agent surface through use of electron microscopy
Authors: Sterman S. , Bradley H. B. 
Published: December 2004

AbstractTheoretically a monolayer or insignificant weight per cent of coupling agent should give optimum properties for fiber glass‐resin composites, contrary to commercial practice. Studies of variation of chemical bonding between the coupling agent and the resin and the study of the degree of bonding of the coupling agents to the glass by extraction techniques have not explained this effect. However, new techniques of electron microscopy have revealed details of loading distribution and agglomeration on the glass fiber which tend to explain this effect.
The degree of bonding between coupling agents and glass filaments ¨ a study ¨
Authors: Eakins William J. 
Published: December 2004

AbstractEvidence indicates that there is a chemical bond between the coupling agent of either silane or chrome complex type and the glass substrate, but that this chemical bond may be strong or weak, depending on the elements making up the bond and the other elements in the immediate area surrounding the bond. These elements can exert either a beneficial or detrimental effect on the strength of that bond. Other evidence is given to show that a vapor phase treatment that applies silane coupling agents like A‐1100 to “E” glass gives the highest known strength retention values. A mechanism is advanced to explain the bridging of unreactive sites on glass surfaces by silane coupling agents applied from solution.
Crystallization kinetic studies of vinylidene chloride‐alkyl acrylate copolymers by torsional measurements
Authors: Riser George R. , Witnauer L. P. 
Published: December 2004

AbstractBy following the changes in torsional modulus as a function of time, the kinetics of crystallization of three copolymers of vinylidene chloride containing 10% mole % alkyl acrylate were investigated and the geometrical growth and nucleation constant of the Avrami equation was determined. Isotherms were superimposable within certain temperature ranges while the nucleation constant decreased with a decrease in temperature. Rate of crystallization increased with increase of the alkyl side chain length.
Radiation and moisture effects in polymerized epoxy resin
Authors: Kline D. E. , Sauer J. A. 
Published: December 2004

AbstractThe effects of moisture and rather large doses of reactor radiation (∼4 × 1011 ergs/gm) on the dynamic properties of polymerized epoxy resins have been investigated over the temperature range of 80°‐450°K and at frequencies from 200 to 1400 cps. Data are presented for both unfilled and aluminum‐filled systems of a bisphenol A based epoxy, (Epon 828) cured with metaphenylenediamine. Moisture absorption (0.88%) causes a shift of the main glass transition near 440°K to lower temperatures (∼25 degrees for unfilled epoxy). This is similar to the plasticizing action of small molecules absorbed in other polymers such as nylon 6‐6. Irradiation to a dose of 4 × 1011 ergs/gm (4 × 109 rads) causes a shift to lower temperatures (∼50 degrees) of the onset of the main transition, and, in addition, results in both a shift to lower temperatures and a decrease in maximum height of the damping peak near 250°K. Chain scission, in a loosening of the structure and the breaking up of the partially flexible connecting groups, may be responsible for these radiation effects.
The relationships between the structures of organic phosphites and their effectiveness in poly(vinyl chloride) stabilization
Authors: Scullin James P. , Rosen Marvin , Girard Theodore A. 
Published: December 2004

AbstractA series of thirty‐three phosphites of varied structural variations were tested at 177°C in a vinyl compound utilizing co‐precipitated barium cadmium laurate or a combination of barium nonylphenate and cadmium 2‐ethylhexoate as the primary stabilizer. Best activity was found with mixed alky‐aryl phosphites.
Prediction of long‐term strength of reinforced plastics. Treatment of prot linear stress‐rupture data
Authors: Loveless Harold S. , Deeley Charles W. , Swanson Donald L. 
Published: December 2004

AbstractFailing stresses of glass‐reinforced plastics and of polystyrene were determined at room temperature. It was found that if an initial load of 40% of the short‐term tensile strength of the material is imposed, good agreement exists between the results of accelerated tests and long‐term, fixed load measurements for periods of 10,000 hours for the reinforced plastics.
High‐speed testing… A new dimension in polymer evaluation
Authors: Silberberg Melvin , Supnik Ross H. 
Published: December 2004

AbstractA new universal tester is described, basically capable of testing samples in the 0.2 to 8000 inches/minute range. With servo controls a load‐elongation curve is obtained which is a measure of material response independent of the machine. Load cell output is fed into the Y axis of an oscilloscope and displacement to the X axis. Useful where deviation from viscoelastic theory is suspected in time‐temperature behaviour, for following impact behaviour and molecular decomposition.
Gas chromatography. A new tool for the analysis of plastics
Authors: Cobler John G. , Samsel E. P. 
Published: December 2004

AbstractIdentification was described by analysis of pyrolysis products, a method which is complicated by the variety of degradation products, but the decomposition products are fairly specific. The pyrolysis technique was used for a quantitative analysis of acrylate and maleate esters in polymers via a hydriodic acid hydrolysis technique. Because of the low volatility of the higher alkyl halides higher esters were saponified at elevated temperatures and the resultant alcohols were chromatographed. Then vinyl acetate was analyzed on the basis of the quantitative yield of acetic acid from polyvinyl acid pyrolysis.
Free radical kinetics in irradiated ethyl cellulose as determined by electron spin resonance measurements
Authors: Loy B. R. 
Published: December 2004

AbstractElectron spin resonance techniques are used to investigate the structure and decay of radicals produced in irradiated ethyl cellulose. Approximately 99% of the radicals trapped at liquid nitrogen temperature appear to be—C2H4. radicals. These decay immeasurably fast at room temperature. The relatively stable doublet that remains is believed to be due to the CHO radical. The kinetics of the doublet decay are studied as a function of temperature and dose. The data may be interpreted as resulting from simultaneous first and second order processes at lower doses and from a second order process at higher doses.
Oxyluminescence‐a new tool for testing the stability of polymers
Authors: Ashby G. E. 
Published: December 2004

AbstractIt was observed that light is emitted upon polymer oxidation; intensity of light is proportional to oxygen concentration on the surface and presence of an antioxidant effects the emission of light. A linear relationship was found to exist between integrated light intensity and the number of carbonyl atoms formed. In addition concentration of antioxidants present and their synergistic effects can be measured by this method.
Methods of studying heterophase conditions in resinous materials
Authors: Kronstein Max 
Published: December 2004

AbstractThe paper discusses polymer materials and synthetic resins as multiphase or heterophase materials. They contain three‐dimensional, insoluble, non‐volatile phase material, as well as soluble and volatile material, which can act as “sweller” for the insoluble phase. As long as the insoluble phase is in a relatively low concentration, the resins are glassy, fusible without decomposition, and thermoplastic. They are like “frozen” solutions of the various phases. As the concentration of the insoluble phase increases, the resins turn insoluble. These gelling, thermosetting materials can be dispersed in strong “sweller fluids”; and from these dispersions, the three‐dimensional material can be precipitated and further investigated. Methods are being discussed.
Dynamic mechanical properties of epoxy resins
Authors: May C. A. , Weir F. E. 
Published: December 2004

AbstractAlthough dynamic mechanical properties of thermoplastic polymers have been studied in great detail and much has been learned about their structure, little has been done in the field of thermosetting resins. The present study involves the use of dynamic methods for determining certain salient features about epoxy resins. A torsion pendulum operating in the range of one cycle per second was used to measure the properties of various epoxy systems. The instrument enabled rapid determination of both internal friction and shear moduli.Two transition peaks in the dynamic loss tangent were observed; one occurring at −60°C, the other at 165°C when a conventional epoxy resin was cured with m‐phenylenediamine. The low temperature peak was effectively demonstrated as due to the glycidyl ether portion of the cured resin system. The major peak or glass transition temperature could be varied in accord with the substituents on the central carbon bridge of the bisphenol portion of the molecule and to a lesser extent by the degree of cross‐linking.
Surface conductance, syneresis and adhesion
Authors: Bikerman J. J. 
Published: December 2004

AbstractElectric surface conductivity χ of purified polyethylene wax in nearly saturated water vapor was about 8 × 10−13mho and in vapor of 0.5% aqueous NH3about 17 × 10−12mho. When 0.1% oleic acid (OA) was added to the wax, χ in the 0.5% NH3vapor was not markedly changed but it was greater at 0.2% and higher concentrations; at 1% OA it was 2 × 10−10mho. These results show that surface conductance (a) may be “developed” by vapors, (b) can be used to detect the onset of syneresis, and (c) is the bulk conductance of the surface film, and, further, that in the polyethylene‐OA system syneresis occurs between 0.1% and 0.2% OA as was deduced from the strength of adhesive joints made with mixtures of OA and polyethylene. Thus, the results confirm the “weak boundary layer” theory of adhesion.
New organic resins and reinforced laminates for service to 300°C
Authors: Freeman James H. , Traynor Edward J. , Miglarese John , Lunn Richard H. 
Published: December 2004

AbstractDemand for structural insulating materials for service in high temperature environments is widespread and the performance characteristics of special grades of silicone or phenolic‐glass laminates at temperatures up to 250°C have been well documented. A new family of polymers, completely aromatic in structure, except for the amido coupling linkage, now shows promise of giving excellent performance at temperatures to at least 300°C in air. Comparative data concerning the retention of mechanical and electrical properties of such laminates after aging at the higher temperature is provided.
Studies of polycarbonate plasticization
Authors: Kozlov P. V. , Asimova R. M. , Perepelkin A. N. 
Published: December 2004

AbstractThe plasticization by dibutyl phthalate, camphor and butyl sterate of polycarbonates prepared by phosgenation of 2,2‐bis‐(4′‐hydroxyphenyl) propane was investigated. Thermomechanical and dynamometric studies of the plasticized polycarbonates show that both intrapacket and interpacket plasticization is possible as for cellulose. In the first case, the lowering of the glassy transition point of polycarbonate films is strictly proportional to the logarithm of the concentration of added plasticizer (dibutylphthalate, camphor). In the second case, after a small drop in the transition point, the latter remains unchanged over a broad range of plasticizer concentrations (butylsterate). A similar relation was observed with respect to the elasticity modulus of the films.
Antioxidant efficiency versus structure
Authors: Baum Bernard , Perun A. L. 
Published: December 2004

AbstractAntioxidant efficiency versus structure was investigated using rate of carbonyl formation at 110 and 170°C of a 20 mil plaque of polyethylene containing 0.01 weight % additive. This study indicates that the following are important in phenolic and amine antioxidants:

The number of H. atoms available: Antioxidant efficiency is increased by adding a second hydroxyl group as well as by introducing a methylene bridge.
The number and location of substituents: Alkyl substitution of the phenolic ring is an important factor in stabilization. Groups which decrease the strength of the NH bond increase the effectiveness of amine antioxidants.
Solubility: The less compatible the antioxidant, the poorer its stabilizing action.
Volatility: Many stabilizers are ineffective at high temperature because of volatilization.
Bridge between rings: A sulfide bridge can be equivalently substituted for a methylene bridge.
The need for stabilization of the radical formed after removal of H: This stabilization could occur via; Hydrogen bonded chelates, resonance and steric hindrance.
Influence of normal stress on creep in tension and compression of polyethylene and rigid polyvinyl chloride copolymer
Authors: O'Connor D. G. , Findley W. N. 
Published: December 2004

AbstractNew apparatus suitable for compression creep tests of slender specimens is described. The apparatus is designed to prevent buckling and to introduce a minimum of friction. Results are reported for tension and compression creep of polyethylene and annealed, unplasticized polyvinyl chloride copolymer at 75 deg F and 50 per cent relative humidity. The stress, σ, strain ε, time t data from these tests were found to be describable with reasonable accuracy by the equation

where εm′, m′, σε and σm are material constants.The results for polyethylene show that the creep in tension and compression were virtually the same. Creep in tension was similar but larger than in compression for polyvinyl chloride.
The stereospecific homogeneous polymerization of vinyl chloride
Authors: Minsker K. S. , Kronman A. G. , Teplov B. F. , Rylov E. E. , Bort D. N. 
Published: December 2004

AbstractPolymerization of the monomer was investigated in organic solvents such as nitro‐compounds, amines, amides, nitriles, ethers, esters, ketones, aldehydes, acids, anhydrides, and some heterocyclic compounds. Crystalline polyvinylchloride was produced in aliphatic aldehyde media at temperatures ranging from 0° to 60°C and highly crystalline polyvinylchloride was synthesized in the presence of preliminarily oxidized butyric aldehyde. The electron diffraction picture of the non‐oriented specimen of the polymer exhibited 19 distinct reflexes.
Use of a new torsion pendulum for polypropylene property evaluation
Authors: Weir F. E. 
Published: December 2004

AbstractA new recording system for a torsion pendulum is described. By its use data on the internal loss and shear modulus of a polymeric material can be obtained quickly and easily in digital form, rather, than the more usual graphical form. The system is simple and easy to operate, is rugged and is inexpensive relative to other systems. The precision available is excellent. An application of the instrument in the determination of the crystallinity of polypropylene is described.
Surface effects of various environments and of thermosetting resins on the strength of glass
Authors: Outwater J. O. , Ozaltin Oguzcan 
Published: December 2004

AbstractGlass rods were etched to reduce their surface flaws and hence to increase their flexural strength. They were then subjected to various environments to see how these would affect their strength and hence their surface. It appeared that no liquid environments affected their strength. This included boiling water. The effect of curing resin against the surface was also shown as was subsequent boiling: Shell Epon 828 appeared to increase the strength of the rods, but only when there was a surface treatment of Union Carbide A‐1100 or Owens‐Corning 801.
Interfacial properties of an amine‐modified silane and its performed polymer at E‐glass surfaces
Authors: Roskos T. G. , Radloff H. R. , Young F. M. 
Published: December 2004

AbstractThe adsorption of triethoxysilylpropylamine and its polymer onto 325 mesh E‐glass from both aqueous and non‐aqueous systems has been investigated. The amount adsorbed from an aqueous solution onto an E‐glass surface corresponds to that obtained by others workers using different techniques. Solid preformed A‐1100 polymer (II) was found to be unstable. Upon prolonged standing a basic gas, identified as ammonia, was liberated. Experimental results indicate that the amount adsorbed is related to the number of ethoxy groups on the molecule. However, the mechanism of silane attachment is still not completely understood.
Some further studies on the effect of glass‐resin type and cure on the strength of laminates
Authors: Brookfield K. J. , Pickthall D. 
Published: December 2004

AbstractThe technique of testing resin/glass laminates has been extended to include three alkali‐containing glasses. NOL rings have been made by a direct filament drawing technique using an epoxide resin system. In each case the strength developed is less than with “E” glass.
Investigations on the strength of alkali‐containing glass fibers
Authors: Weisbart Hans 
Published: December 2004

AbstractThe assertion was checked that alkali containing glass fibers, which evolve caustic bases when attacked by water, are, by this fact, responsible for the mechanical deterioration of reinforced plastics. Glass fibers of different chemical composition, when extracted with water, showed no correlation between amount of alkali in the glass and alkali leached out. Tensile strength of glass fibers is not a function of alkali content. Subjected to water, all types of glass fibers keep their strength except when boiled. This applies to fibers coated with coupling agent or in the native state. Deterioration of laminates under the influence of water seems to be primarily a function of the interface.
New aspects of melt fracture
Authors: Benbow J. J. , Lamb P. 
Published: December 2004

AbstractThe movement of coloured markers (polydimethyl siloxane and low density polythene) placed near the die entry before extrusion or injected through the side of the die during extrusion has been measured both above and below the onset of instability. During stable flow the observed velocity distributions are similar to those predicted by assuming that polymer at the die wall is stationary, but when melt fracture occurs there is movement at the wall. The possibility of a stick‐slip mechanism being responsible for unstable flow is examined and evidence in support of this hypothesis is presented. Available evidence suggests that for a given molecular weight, the critical shear stress increases with the polarity of the polymer, and the material of which the die is made has been found to affect the instability.
The status of non‐Newtonian polymer flow
Authors: Porter Roger S. , Johnson Julian F. 
Published: December 2004

AbstractThis study summarizes the flow behavior of concentrated and melt systems of linear amorphous polymer. For low molecular weight polymer, viscosity increases regularly with a lower power dependence on molecular weight. This dependence decreases towards first power with increasing temperature but is independent of shear, with viscosities being constant up to the highest attainable steady state stresses, about 106 dynes/cm2. At a higher molecular weight, 2,000–40,000, depending on polymer type, the viscosity dependence on molecular weight changes abruptly to a high power which is generally about 3.4. Above the transition, this high power function is independent of temperature but depends markedly on shear. Non‐Newtonian flow sets in abruptly and predictably above the transitional molecular weight.
Polymers with conjugated bonds in the macromolecular chains
Authors: Berlin A. A. , Popova Z. V. , Yanovskii D. M. 
Published: December 2004

AbstractThe effect of polymers with conjugated bonds, namely polyphenylvinylene, phenylacetylenep‐diethinylbenzene copolymer and thermally dehydrochlorinated polyvinylchloride, upon the stability of polyvinylchloride suspensions has been investigated. It has been shown that polymers with conjugated double bonds are efficient inhibitors of the thermal dehydrochlorination of polyvinylchloride. The most active inhibitor, polyphenylvinylene, is not light stabilized.
Crystalline organization in useful plastics
Authors: Starkweather Howard W. 
Published: December 2004

AbstractThe size of the crystallites in nylon 66, polytetrafluoroethylene, and polyethylene correlates with the degree of crystallinity. This supports the suggestion that the amorphous content of partially crystallized polymers can be attributed to chain folds and other regions directly related to the crystalline structure, at least down to a level of 40–60% crystallinity. In all cases, the term “percent crystallinity” is a useful unifying concept expressing the over‐all degree of order including mesomorphic structures, the relative amounts of ordered and disordered material, and the quality of the ordered regions.
Tensile creep and recovery of compression molded polypropylene samples
Authors: Hiltz A. A. 
Published: December 2004

AbstractA simplified creep apparatus was used to evaluate the creep and recovery of polyethylene and polypropylene. The creep resistance of polypropylene containing as much as 9% n‐heptane (boiling) soluble material is superior to that of linear polyethylene. The lower the boiling n‐heptane soluble content, the better the resistance to creep. The creep resistance of polypropylene is also improved by annealing.
Determination of functional groups in epoxy resins by near‐infrared spectroscopy
Authors: Dannenberg H. 
Published: December 2004

AbstractAnalysis in liquid or solid state and in various conditions of cure, have been developed. The analysis is carried out by spectroscopy in the near‐infrared region. Epoxy values are determined preferably at 2.205 microns, or else at 1.159 microns. The required path length in the specimen is between 1 and 10 mm, solid resins were examined either in disposable glass cells or in the form of cast sheet. A direct method of evaluation is used when the path length is precisely known, a relative method based on internal calibration when this is not the case. Similarly, a near‐infrared method for the determination of hydroxyl groups in epoxy resins was developed. The use of the isosbestic principle led to an accurate method for the determination of hydroxy values in uncured epoxy resins.
Influence of channel curvature on flow, pressure distribution, and power requirements of screw pumps and melt extruders
Authors: Booy M. L. 
Published: December 2004

AbstractThe influence of channel curvature on flow through screw pumps and melt extruders is derived for infinite channel aspect ratios. Flow rate and horsepower relations for flow of Newtonian liquids are given as functions of design parameters. The results of this cylindrical theory are compared with those of conventional theories. Curvature factors converting the equations of the flat plate theory to those of the cylindrical theory are shown. Pressure distributions in screw pump channel are analyzed.