bluuebunny/crossref_metadata_2025_split huggingface dataset:
A compound pendulum for dynamic viscoelastic property measurements
Authors: Rosenthal L. A. , Ungermah A. J. 
Published: December 2004

AbstractA compound pendulum system has been developed for the measurement and study of the modulus of elasticity and internal damping properties of a viscoelastic specimen through a range of temperatures.An analysis of the apparatus and the essential describing equations are presented. Test results for several materials are presented. In the region of the heat distortion temperature many materials exhibit a sharp peak in their damping characteristics. The modulus of elasticity drops rapidly in this region. Modulus of elasticity results obtained compare favorably with static testing machine data. The compound pendulum system described provides a simple technique for these physical property determinations continuously over a range of temperatures.
The nature, origin and effects of internal stresses in reinforced plastic laminates
Authors: Matta J. A. , Outwater J. O. 
Published: December 2004

AbstractThere is a tension set up between the resin and the glass upon curing. A simple experiment has been devised to measure this tension and to note how it changes with time and temperature. It is found that it does not diminish with time and that it is linearly dependent on the highest temperature to which the resin has been brought during or after cure. NOL‐type rings were made with the same resin systems and subjected to different cure temperature so that the effect of the different shrinkage tensions on the physical properties be examined.
The bonding of fillers to thermosetting resins
Authors: Vanderbilt Byron M. , Jaruzelski John J. 
Published: December 2004

AbstractUse of silica was emphasized since it is available in high purity, and since it is a major ingredient in all glass fibers. Other fillers employed include the aluminas, silicates, glass, and simple salts. When using a hydrocarbon type thermosetting resin and no chemical coupling agent, all fillers were substantially equivalent from the standpoint of strength of moldings. When using a vinyl silanol type coupling agent in the mix, there was a vast difference, however. Silica and alumina are strongly coupled via the silanol linkage of the silane, the glasses and complex silicates such as clays are intermediate, and simple salts such as carbonates and sulfates do not respond at all.
Moldability of plastics based on melt rheology. Part 1—theoretical development
Authors: Weir F. E. 
Published: December 2004

AbstractAn expression for the “average” viscosity of a polymeric material realized during an injection molding shot is developed. From this expression certain rheological quantities are taken which should better express ease of molding than do conventional testing methods. Comparison is made between actual molding experience and quality as predicted by the new method.
Moldability of plastics based on melt rheology. Part II—practical applications
Authors: Weir F. E. , Doyle M. E. , Norton D. G. 
Published: December 2004

AbstractAn expression for the “average” viscosity of a polymeric material realized during an injection molding shot is developed. From this expression certain rheological quantities are taken which should better express ease of molding than do conventional testing methods. Comparison is made between actual molding experience and quality as predicted by the new method.
The relationship between optical exaltation and polymerizability of olefins. Correlation of exaltation with copolymerization
Authors: Downey Paul M. , Butler George B. 
Published: December 2004

AbstractMonomers for which the necessary information was obtained for comparison included the following: styrene, α‐methylstyrene, cis and trans‐propenylbenzene, allylbenzene, m‐methylstyrene, p‐methylstyrene, o‐, m‐, and p‐chlorostyrene, 2,3‐, 2,4‐, 2,5‐, 2,6‐, 3,4‐, and 3,5‐dichlorostyrene, p‐ethylstyrene, and p‐tert‐butylstyrene. In both free radical and ionic copolymerizations involving similar monomers, plots of the logarithms of the relative reactivities of several substituted styrenes toward the styrene and methyl methacrylate radicals versus the differences existing between the exaltations of substituted styrenes and the exaltation of styrene were strikingly similar to those in which Hammett's sigma values for the styrene substituents were plotted against the relative reactivities of the substituted styrenes.
The polymerization and long‐term stability of room temperature curing epoxy resins
Authors: Steele Doris V. 
Published: December 2004

AbstractThe effect of resin mass on the degree of crosslinking during the initial polymerization of three typical polymer compounds was determined by electrical resistivity techniques. Activation energies for the electrical conduction process (Ec) were calculated and used as an index of the extent of additional crosslinking occurring during sixteen months of storage. Test data show continued polymerization at slow rates for periods of time ranging from three days to over sixteen months before the polymerization process is completed. The final degree of crosslinking is shown to be dependent on the extent of initial crosslinking.
Polymerization of methacryloyl chloride in selected solvents
Authors: Blatz Paul E. 
Published: December 2004

AbstractMethacryloyl chloride was polymerized in a number of solvents, and the polyacid chloride was converted into the methyl ester. The yield and viscometric molecular weight are given for each sample, whereas the osmometric molecular weight is given for selected samples. The choice of solvent controls the degree of polymerization between the limits of 500 and 8,800. Polymer yields were about 20% and the degree of polymerization was 1500 when dioxane was used as a solvent, whereas the yield increased to 45% and the DP was very high when such solvents as cyclohexane and n‐hexane were used. Polymerization in solvent mixtures gave intermediate molecular weight values. Infrared analysis showed the presence of anhydride.
Microencapsulation by interfacial polycondensation
Authors: Mackinney Herbert W. 
Published: December 2004

AbstractA water immiscible liquid is encapsulated in a thin skin of an insoluble copolymer by dissolving a difunctional acid chloride in said liquid and spraying the solution in fine droplets into a dilute aqueous solution of excess glycol or diamine. The polymer, which is not hygroscopic, forms as an insoluble film on the periphery of each drop. The microcapsules may be separated from the aqueous phase and dried without coalescing. Dyes, pigments, stabilizers, and other materials may be incorporated within the capsules.
1,2,2‐Trifluorovinyl phenyl ether and 2,3,4,5,6‐pentafluorophenyl 1,2,2‐trifluorovinyl ether and their polymers
Authors: Pummer Walter J. , Wall Leo A. 
Published: December 2004

Abstract1,2,2,‐Trifluorovinyl phenyl ether and 2,3,4,5,6,‐pentafluorophenyl 1,2,2‐trifluorovinyl ethers have been prepared, and the nucleophilic reactions of the phenoxide and 2,3,4,5‐pentafluorophenoxide salts with tetrafluoroethylene have been investigated. In general, it is some‐what difficult to control the reaction so as to produce the desired olefinic monomer. Under truly anhydrous conditions and when other sources of active protons are avoided, the olefin is the chief product if excess tetrafluoroethylene is used. The monomer produced is very reactive with phenoxide ions, and the diphenoxyolefins are the chief secondary products. Both monomers failed to polymerize under normal, free radical conditions. With boron trifluoride an oily material was obtained from the trifluorovinyl phenyl ether. High pressure and gamma rays converted both monomers into polymers.
Synthesis of perfluorostyrene and (2,2‐difluorovinyl) perfluorobenzene (a‐hydroheptafluorostyrene)
Authors: Antonucci Joseph M. , Wall Leo A. 
Published: December 2004

AbstractThese compounds were synthesized by starting with the addition of the Grignard reagent of bromopentafluorobenzene to trifluoroacetaldehyde and chlorodifluoroacetaldehyde, respectively. The new alcohols, 2,3,4,5,6‐pentafluoro‐α‐(trifluoromethyl) benzyl alcohol and 2,3,4,5,6‐pentafluoro‐α‐(chlorodifluoromethyl) benzyl alcohol, are formed in good yield and undergo smooth conversion to (1,2,2,2‐tetrafluoroethyl) perfluorobenzene and (2‐chloro‐1,2,2‐trifluoroethyl) perfluorobenzene, respectively, in excellent yield when treated with sulfur tetrafluoride using n‐pentane as diluent. The major pyrolysis product was identified as (2,2‐difluorovinyl) perfluorobenzene (α‐hydroheptafluorostyrene) and the minor one as perfluorostyrene. Perfluorostyrene was also synthesized in excellent yield by bromination of (1,2,2,2‐tetrafluoroethyl) perfluorobenzene and subsequent pyrolysis of the brominated derivative. The dehydrochlorination of (2‐chloro‐1,2,2‐trifluoroethyl) perfluorobenzene provided another good synthesis of perfluorostyrene.
Heat‐transfer calculations in crystalline plastics
Authors: Gloor W. E. 
Published: December 2004

AbstractThe problems of unsteady‐state heat transfer associated with the melting and cooling of crystalline plastics such as polyacetals, high density polyethylene and polypropylene, are complex because of the latent heat of fusion that must be dealt with in problems where the temperature range being considered extends across the melting range. In the case of polyacetals, the use of a computer is shown in the literature to provide solutions to those problems. For many molding shops, such aids are not available. Numerical methods for the solution of such problems have been investigated, and their results are compared with those obtained using a computer and published for polyacetals. Cooling curves derived from numerical calculations, for slabs and rods made from high density polyethylene and polypropylene, are presented. Applications of the method are indicated.
Gamma irradiation of polytetrafluoroethylene in chlorine
Authors: Florin R. E. , Wall L. A. 
Published: December 2004

AbstractFilms of polytetrafluoroethylene, irradiated in halogen atmospheres, decrease in ultimate tensile strength and elongation at break almost as rapidly as in oxygen. The rate of degradation is approximately independent of chlorine pressure down to about 1 mm Hg. The phenomena can be explained semi‐quantitatively in terms of first order, cage reactions of scission, recombination, and reaction with chlorine, complicated by diffusion at low pressures. However, all reaction and diffusion parameters must shift with gradual increase of crystallinity.For a given decrease of elongation at break, polytetrafluoroethylene irradiated in a vacuum retains a relatively higher ultimate tensile strength. In the copolymer of tetrafluoroethylene and hexafluoropropylene, the changes in ultimate tensile strength and elongation at break are much slower under all conditions. Both polytetrafluoroethylene and the copolymer retain appreciable tensile strength but little elongation up to a dose of 2 x 108r.
Vinyl chloride/bicyclo (2.2.1) hepta‐2,5‐diene copolymers: High softening, easily processed vinyl resins
Authors: Zutty N. L. , Whitworth C. J. 
Published: December 2004

AbstractBicyclo [2.2.1] hepta‐2,5‐diene, the reaction product of acetylene and cyclopentadiene, and vinyl chloride readily copolymerized by a novel mechanism, to form copolymers containing the nortricyclene group whose softening points rapidly increase with increasing nortricycl one concentration. For each weight per cent copolymerized bicycloheptadiene, the softening point of the vinyl resin is increased about 1°C, making it the most effective comonomer known for this purpose. At the same time increasing nortricyclene concentration disrupts polymer crystallinity, lowers the resin's melting point, and hence its processing temperature, by about 3°C for each weight per cent copolymerized.
Tensile impact properties of thermoplastics
Authors: Simpson E. H. , Polleck R. E. 
Published: December 2004

AbstractThe impact strength of a thermoplastic is shown to be a strong function of several variables. Among these are type of molding, molding conditions, molecular orientation, test temperature, and notches. Particularly significant is a maximum in the response of impact strength to molding temperature. The tensile impact test was used as a tool for these determinations.
The quenched state of polypropylene
Authors: Gailey J. A. , Ralston R. H. 
Published: December 2004

AbstractThere are several pieces of evidence in the published literature for the existence of a hexagonal crystalline form of polypropylene. Evidence obtained by infrared absorption, x‐ray diffraction, differential thermal analysis, and annealing experiments is consistent with the view that the quenched state of polypropylene is a truly crystalline one (presumably of hexagonal type) with a very small crystallite size.
Dielectric measurements elucidate structure of acrylic polymers
Authors: Steck Naomi S. 
Published: December 2004

AbstractDielectric measurements made at 60 cycles per second over a temperature range of −40 to 200°C on small (0.2 g) samples arc most useful in studying acrylic polymers. Not only has this method elucidated structure, but the study of some structures has led to new interpretations emphasizing the value of this type of measurement. Data on a number of acrylic polymers are shown. Several copolymer systems are discussed. It is suggested that 60 c/s measurement of stereospecific PMMA samples can show more about molecular arrangements than has previously been revealed.
Fireproofing of polymers with derivatives of phosphines and with halogen‐phosphorus compounds
Authors: Boyer N. E. , Vajda A. E. 
Published: December 2004

AbstractChemical structures limited to phosphines and their derivatives, including phosphine oxides, phosphonium salts and halogen‐phosphorus compounds useful for fireproofing are discussed. In addition to these P‐C bond containing compounds, structures containing P‐O‐C bonds are mentioned only if they are directly formed from halophosphorus substances. The general approaches to fireproofing are described. They include physical changes, unreactive additives, reactive comonomers, substitution of other functional groups and addition to a preformed polymer. Much of the literature is reviewed and the commercial importance of certain methods for both cloth and plastics are indicated.
Pyrolysis of new fluoropolymers
Authors: Straus S. , Wall L. A. 
Published: December 2004

AbstractFour new fluoropolymers were pyrolyzed in a vacuum to study rates of volatilization and to identify decomposition products. The polymers thus studied were polyperfluoropropylene, polyperfluoroheptene, poly‐4‐chloroperfluoroheptadiene‐1,6 and poly (1,2,2‐triflluorovinyl phenyl ether). Polyperfluoropropylene yielded 100% monomer at temperatures of 300 to 400°C gave an activation energy of 56.6 Kcal/mole. Polyperfluoroheptenes of different molecular weights also yielded 100% monomer on heating. However, they had lower thermal stability than polyperfluoropropylene, but a higher activation energy and a higher pre‐exponential factor. Poly‐4‐chloroperfluoroheptadiene volatilized at a rate of approximately 1% per minute at 380°C. There was very little monomer produced on thermal decomposition and an activation energy of 60 Kcal/mole was obtained from rates of volatilization at 362, 374, and 381°C. Poly (trifluorovinyl phenyl ether) showed a 25% carbonized residue at 500°C pyrolysis. The polymer decomposes into fragments containing very little monomer. Undesirable low molecular weight components in the polymer are still to be eliminated.
The relationship between chemical structure and properties of polyester resins
Authors: Hayes B. T. 
Published: December 2004

AbstractAttempts are made, in the light of published information, to decide the factors affecting network structure in commercial polyester resins and the effect of network variations on physical properties of polyfumarate‐styrene copolymers. An approach towards the optimum in chemical and heat resistant polyester laminates is suggested by examination of the influence of polyester chain structural variations on these properties.
Phosphorus‐containing phenolic resins
Authors: Kindley L. M. , Filipescu N. , Pappas E. , Huether C. 
Published: December 2004

AbstractThe character of the residues from pyrolytic decomposition of organo‐phosphorus polymers has suggested the use of such materials in ablative materials required for heat shields in reentry vehicles, rocket nozzles, etc.Phosphorus‐containing phenolic resol and novolak resins were prepared by condensing di(p‐hydroxyphenyl)‐phenyl‐(phosphine oxide) with aldehydes. The mechanical properties of the basic phosphorus‐phenolics were improved by internal plasticization through chemical reaction of the resin in the early stages of polycondensation with acrylonitrile‐butadiene copolymers (NBR) and with silences and slicone resins. To improve the compatibility of the phosphorus phenolics with NBR copolymers, the phosphorus‐containing phenolics were initially etherified by “butanolization” in order to decrease their polarity.The preparation of coatings and molded discs from some modified and unmodified phosphorus‐containing phenolic‐resin formulations is described. Preliminary observations relating to the properties of the trial products are reported.
Thermal and oxidative degradation of polymers
Authors: Hawkins W. L. 
Published: December 2004

AbstractOxidation of many polymers occurs by a free‐radical, chain mechanism similar to that developed for the oxidation of volatile hydrocarbons. The rate at which various polymers oxidize and the extent of the reaction is influenced both by the physical and by the chemical structure of the particular polymer. Important morphological changes may also occur as a result of oxidation. Polymer degradation by oxidative reactions can be inhibited effectively at several stages in the over‐all reaction. Synergistic combinations in which each component of a stabilizer system inhibits primarily at one of these stages are particularly effective.
Why do plastics stress‐crack?
Authors: Howard J. B. 
Published: December 2004

AbstractIn this brief review, environmental stress‐cracking in polyethylene is taken as a typical example of the broad phenomenon of stress‐cracking and the major variables affecting its operation are enumerated. In addition to stress, these include molecular weight, molecular weight distribution, the amount and nature of the crystalline phase present, the nature of the “environment,” the importance of its ability to alter the surface energy characteristics of the affected polymer, and the effects of temperatrue. The need for selecting an appropriate test procedure is stressed, and the probable significance of certain recent advances in comprehension of the crystallization mechanics of these materials is suggested.
On aging of plastics in structural applications
Authors: Ingle George W. 
Published: December 2004

AbstractExpanding interst in using plastics for structural pruposes immediately focuses attention on their poermanence. This desired quality is broadly defined as the persistence of a specific set of properties of a given asembly or manufactured product, in its appropriate environment, for an economically justified duration. Analysis of existing test methods, primarily those standardized by ASTM, shows no really applicable techniques for measuring permanence. By contrast, more advanced thinking presented by recent ASTM stmposia indicates two general routes to the porediction of performances. Whether a rigorous “micromechanistic” technique is used, or the empirical “macroanalytical” approach, or some combination of the two, is considered irrelevant. What is important is that experimental programs be started to provide better measures of permanence.
Weathering of plastics
Authors: Kinmonth Raymond A. 
Published: December 2004

AbstractThe current status of weathering of plastics is reviewed. As a better understanding of the effective degradative parameters of weather are obtained, it is aparent that complex interactions occur. Present laboratory exposure tests do not simulate natural conditions sufficiently to provide the much neede reliable short term exposure test for predicting long term durability. While a major step forward occurred with the introduction of filtered xwnon lamps, which simulate terrestrial sunlight both in intensity and distribution, industry‐wide support of fundamental studies of degradation is necessary if weathering studies are to be conducted scientifically.
Fifteen years of weathering results
Authors: Rugger George R. 
Published: December 2004

AbstractThe work carried out at Picatinny Arsenal on the weathering of plastics over the lat 15 years is briefly described. Although the perid of work was 15 years, individual systems were exposed for only three years. The need for running parallel tests on materials stored indoors for the three years is pointed out as a means of separating the effects of daging from weathering. Also brielfy discussed is the influence which the test method chosen can have on the judgment reached. The requirements of the application are as important as the inherent durability of the material. Improved compounds are becoming available and complete reporting of both favorable and unfavorable resuts is urged as a means of lending guidance in the search for still better compounds.
Poly‐β‐hydroxybutyric acid—a naturally occurring thermoplastic material
Authors: Werber F. X. , Baptist J. N. 
Published: December 2004

AbstractPoly‐β‐hydroxybutyric acid has been isolated in quantities sufficient for characterization and evaluation of mechanical properties from both Bacillus megaterium and a special strain of Rhizobium. Its presence in a larger variety of bacteria than previously suspected has been demonstrated by a screening method based on density‐gradient centrifugation. The intrinsic viscosity of the isolated polymer has been shown to depend on the technique of isolation; basic solvents facilitate hydrolytic cleavage of the polyester. Mechanical properties of the polymer are based on the high crystallinity and polarity of the material; in a highly crystallized state, it is quite brittle, but its rigidity exceeds that of polypropylene. Thermal degradation of molecular weight, due to beta‐eliminatin of the carboxyl group from the polyester structure, severely limits processing of the polymer in the melt.
Studies of the thicknesses of adsorbed glass finishes by ellipsometry
Authors: Tutas D. J. , Stromberg R. , Passagila E. 
Published: December 2004

AbstractThe thickness of the adsorbed layer of two glass finishes, vinyl tris (2‐methoxyethoxy) silane and gamma‐aminopropyltriethoxysilane, was measured by ellipsometry. The vinyl silane was adsorbed on glass from solutions in water and in methyl ethyl ketone. The adsorption from water resulted in a film initially at least 50 Å thick, which increased in thickness with time. Adsorption from methyl ethyl ketone solution resulted in a film of about 10 Å. The amino silane was adsorbed on glass and on chrome from soutions in water. Adsorption on glass resulted in a film at least 60 Å in thickness, which remained constant over a period of about 5 hours. Adsorption on chrome resulted in a film about 10 Å in thickness. From the results it appears that a polymer, rather that small molecules of glass finish, is adsorbed from the water solution on glass and that small unpolymerized “finish” molecules are adsorbed from the methyl ethyl ketone solution.
Material properties of reinforced plastics
Authors: Shaffer Bernard W. 
Published: December 2004

AbstractThe moduli of elasticity of reinforced plastics with uni‐directional filaments either parallel or normal to an applied force are evaluated in terms of the material composition. Expressions are then derived which relate its moduli of elasticity and Poisson's ratios for an arbitrary filament orientation with its material properties in the direction of and normal to the unifilament orientation with its material properties in the direction of and normal to the unidirectional filaments. Filaments. The stress‐strain relations of filament reinforced plastics are also derived.