bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of solvent treatments on the mechanical properties of nylon 6
Authors: Rubin J. , Andrews R. D.
Published: December 2004

The effects of absorbed solvents and chemical agents on the stress‐strain and dynamic mechanical properties of nylon 6 film have been examined. The agents investigated were: water, benzyl alcohol, phenol and iodine. These materials produce changes in the crystalline structure as well as plasticization when they are absorbed. Repeated introduction and removal of phenol indicated that the change of structure takes place completely during the first absorption; after that, the effects of absorption are reversible. The pure plasticizer effect can therefore be observed by comparison of a sample containing plasticizer and a sample from which the plasticizer has been subsequently removed. The general effect of absorbed plasticizer (except for iodine) seems to depend primarily on the amount of plasticizer absorbed, and very little on its exact chemical nature. However, different agents can produce different crystalline forms. A method of analyzing the stress‐strain curve is hypothesized based on the concept of a two‐phase solid state structure consisting of a crystalline lattice imbedded in an amorphous matrix.
A macroscopic analysis of composites containing layered spherical inclusions
Authors: Matonis V. A. , Small N. C.
Published: December 2004

This investigation considers a hypothetical three‐phase ordered composite to permit the design of a new material both stiffer and tougher than the matrix phase alone. The required elastic solution is greatly simplified and was based on a single layered inclusion in an otherwise infinite matrix under uniaxial tension. The solution presented is exact and generalized to accommodate any number of concentric layers of different thickness and composition.
Fine structures and fracture processes in plastic/rubber two ‐phase polymer systems. I. Observation of fine structures under the electron microscope
Authors: Matsuo M. , Nozaki C. , Jyo Y.
Published: December 2004

Fine structures of several plastic/rubber two ‐phase polymer systems were studied by means of direct observations of ultrathin sections under the electron microscope using osmium tetroxide staining and a hardening procedure developed recently by Kato. Samples used are several types of both ABS polymers and high ‐impact polystyrenes, and several PVC/rubber blends and the results were discussed in relation to their dynamic viscoelastic properties. It is suggested that these studies may fruitfully be extended to clarify the structure ‐to property relationships by use of this method.
The effect of penetrant activity and temperature on the anomalous diffusion of hydrocarbons and solvent crazing in polystyrene part I: Biaxially oriented polystyrene
Authors: Hopfenberg H. B. , Holley R. H. , Stannett V.
Published: December 2004

The effects of temperature and penetrant activity on the sorption kinetics and equilibria of a series of alkanes in glassy, biaxially oriented polystyrene were studied. Normal isomers of pentane, hexane, and heptane cause crazing of polystyrene film samples at high penetrant activities (> 0.85). Crazing kinetics are identical to the kinetics of Case II transport. Transport of these normal hydrocarbons in glassy polystyrene in the temperature range 25 to 50°C is markedly non‐Fickian; limiting Case II transport is observed at activities in exces of 0.6. Sorption appears to be controlled by highly activated relaxation processes including primary bond breakage at these high penetrant activities. Fickian diffusion behavior is approached, however, as penetrant activity is reduced. Sorption of the branched isomers of these compounds does not result in polymer microfailure. The sorption kinetics of the branched isomers, although time dependent, appear to be controlled primarily by thermally activated diffusion rather than large scale polymer relaxations which control Case II transport.
Mechanical behavior of polytetrafluoroethylene around the room‐temperature first‐order transition
Authors: Koo G. P. , Andrews R. D.
Published: December 2004

The effect of the room‐temperature first‐order transition on the plastic yield behavior of polytetrafluoroethylene (PTFE) has been investigated. Stress‐strain curves were measured at different strain rates and temperatures. Tensile creep under constant dead load was also measured as a function of temperature and stress level. The effect of degree of crystallinity was investigated by using both a rapidly quenched and slow‐cooled polymer. Observations were extended to large deformations, so that the phenomenon primarily observed was plastic yield rather than linear viscoelastic behavior.

The curve of yield stress vs. temperature in the temperature range from –50 to +68°C was found to be almost identical with the curve of elastic modulus vs. temperature; the yield stress shows a marked local decrease at the first‐order transition. The yield elongation was almost constant (at about 5%) over this same range, which is in accord with the above result. The more highly crystalline polymer is always more rigid than the less crystalline polymer at small deformations, but above 19°C its stress‐strain curve shows a “cross‐over” in stress level with the curve of the less crystalline polymer as extension increases. That is, above 19°C the less crystalline polymer shows a more rapid rate of “strain hardening”, even though the strain‐hardening effect is pronounced in both polymers. Attempts to apply time‐temperature superposition to creep data at different temperatures were partially successful; the lateral shifts required corresponded to an activation energy of approximately 80 kcal.

The experimental observations suggest a model of the solid‐state structure of PTFE which could be described as an “elastic‐plastic network”, in which crystalline domains are connected by elastic amorphous regions, and in which the crystalline domains can flow plastically at sufficiently high stress or temperature.
The mechanical and other physical properties of polyelectrolyte salts in the solid state
Authors: Nielsen L. E.
Published: December 2004

Salts of polyacrylic acid can be fabricated in heated molds using mixed powders of polyacrylic acid and metal oxides. Because of the strong intermolecular forces in these polyelectrolyte salts, they have elastic moduli several times greater than the moduli of conventional plastics. They also have very low coefficients of expansion and high compression strengths. Composites containing metallic and inorganic fillers have also been made and their mechanical properties measured.
Some physical properties of multilayered films
Authors: Schrenk W. J. , Alfrey T.
Published: December 2004

Some properties of multilayered films are summarized in relation to the properties of the component materials. Polymers may be selected for co‐extrusion into layered films to obtain various combinations of properties, such as barrier, stiffness, heat sealability, optics, and toughness. Properly chosen combinations of high and low modulus materials exhibit mutual interlayer reinforcement. Permeabilities of multilayer films can be calculated from layer geometry and individual component properties.
Entrance flows of polymeric materials: Pressure drop and flow patterns
Authors: Boles R. L. , Davis H. L. , Bogue D. C.
Published: December 2004

Flow at the entrance of a tube or channel is of interest in many polymer processes. Except for mathematical treatments at high Reynolds numbers and in creeping Newtonian flow, one must turn to empirical correlating equations and qualitative observations. These are discussed in two parts, one on pressure drop and the other on flow patterns. The discussion of pressure drop is largely a review, dealing with inertial, viscous, and elastic contributions to the pressure drop in tapered and sharp‐edged entrances; also presented are new data for a viscoelastic polymer solution in tapered cone entrances. In the section on flow patterns, stress birefringent data for a very elastic solution flowing into a channel entrance show an unusual effect: stress discontinuities, not unlike “shock waves,” upstream and downstream of the entrances. This is in contrast to Newtonian and less elastic materials in which the stress patterns change gradually between the developed flow region and the entrance region.
Viscoelastic behavior of boron fiber‐epoxy resin composites
Authors: Schrager M. , Carey J.
Published: December 2004

A torsion pendulum study of boron fiber‐epoxy resin composites has shown marked deviations, at elevated temperatures, from the predicted behavior. A new damping peak at approximately 180°C as measured at 5 Hz is present which appears to be independent of the type of epoxy resin present in the matrix. This peak is attributed to interfacial effects between the boron fibers and the matrix resin. A linear model is tentatively proposed to explain this effect.
The interaction of alkoxy silane coupling agents with silica surfaces
Authors: Kaas R. L. , Kardos J. L.
Published: December 2004

The interactions of γ‐aminopropyltriethoxy silane (A‐1100), γ‐methacryloxytrimethoxy silane (A‐174), γ‐glycidoxytrimethoxy silane (A‐187), and ethyltriethoxy silane (A‐15) with silica surfaces have been studied by means of infrared spectroscopy. The results indicate that the major force holding the silane to the silica surface after application from dilute solutions is primary chemical bonding. These bonds are formed by a condensation reaction between silanols on the hydrolyzed form of the silane and hydroxyl groups on the silica surface. In the case of the amino‐silane (A‐1100), hydrogen bonding was found to exist but was of minor importance in bonding the silane to the surface. In studying the effects of the addition of water, acetic acid, or n‐propylamine to various silane treating solutions, it was found that n‐propylamine has a unique catalytic effect on the condensation reaction. This catalytic effect explains the observation that γ‐aminopropyltriethoxy silane is more reactive than the other silanes studied. It is felt that silanes not containing an amine group can be made more effective if they are applied in the presence of an amine catalyst.
Crystallization studies on deformed polybutene‐1 melts
Authors: Wereta A. , Gogos C. G.
Published: December 2004

An apparatus was designed and built which allowed an investigation concerning the morphology and kinetics of crystallization of a deformed polybutene‐1 melt. The polymer was quenched from a temperature above its melting point to one of two crystallization temperatures. The supercooled melt was then sheared and allowed to crystallize isothermally while the internal stress in the melt was continuously recorded. A polarizing microscope was employed for the simultaneous study of the resulting morphological changes. By properly accounting for thermal contractions within the apparatus caused by the quenching operation, as well as the imposed shear strain, a strain history of the polymer during crystallization was developed. From this strain history and the assumption that the volume contraction resulting from crystallization was isotropic, approximate kinetics of crystallization in a deformed polymer melt were determined.
Lower Newtonian viscosities of polystyrene
Authors: Chee K. K. , Rudin A.
Published: December 2004

A falling coaxial cylinder viscometer was used to measure the melt flow behaviour of a commercial polystyrene with Mw 260,000. The shear stress region extended down to 0.6 × 104 dynes/cm2 and shear rates were as low as 3 × 10−2 sec−1 at 186°C. The shear rate‐shear stress plots were linear at low shear stresses with slopes (differential viscosities) of 3.3 × 105 poises at total shear less than 120 units and decreasing differential viscosity with higher total shear. The flow curves at relatively low total shear were initially dilatant and became pseudoplastic with increasing shear stress. The inflection point represents a Newtonian apparent viscosity, which agrees fairly well with literature values for polystyrenes of the same Mw. Newtonian apparent viscosity is characteristic of a point value of shear stress and shear rate and is not necessarily a plateau region. Observation of a Newtonian region with decreasing shear stress or shear rate does not prove that this flow regime persists unchanged to zero values of the experimental parameter. The existence and magnitude of the Newtonian apparent viscosity reflects shear history of the polymer as well as its constitution and molecular weight distribution.
Application of holographic interference technique to mechanical studies of polymeric solids
Authors: Matsuoka S. , Wallder V. T. , Beauchamp H. L.
Published: December 2004

Holographic reflective interference patterns arising from a small displacement of the surface of polymer solids provide a very sensitive means for detecting the internal stress related to molecular orientation, as well as measuring very small time dependent deformations not accessible by conventional means. Applicability of this technique using 6328Å laser light on various mechanical studies in polymeric solids is discussed.
Differential thermal analysis using high frequency dielectric heating II. Curing kinetics studies
Authors: Wald S. A. , Winding C. C.
Published: December 2004

A previous paper described the theory and equipment of Differential Thermal Analysis using High Frequency Dielectric Heating, DTA/HF. Curing studies using DTA/HF on cis‐1,4‐polyisoprene rubber filled with 50 phr of CaCO3 and containing from 1.5 to 4.5 phr of dicumyl peroxide (DCP) curative indicated that below about 185°C, the curing reaction was first order with respect to DCP; the mean activation energy was 32.6 kcal/mole; and the heat of reaction ranged from 60 to 80 kcal/mole DCP. These results are in agreement with published results. Above 185°C both thermodynamic and kinetic evidence implied that the reaction mechanism changed; the first order peroxide decomposition no longer controlled the overall rate of reaction.

The curing of both stereo styrene‐butadiene rubber (SBR) and cis‐1,4‐polybutadiene rubber (BR) containing 50 phr of CaCO3 and 0.5 phr of DCP was found to follow first order kinetics as expected. The magnitude of the heat of curing was used to determine the frequency of a vinyl propagation‐type cross‐linking reaction. Eight to 36 crosslinks per molecule of DCP were obtained. This reaction became more extensive at high temperature, in agreement with published results.
The effect of time and temperature on the mechanical behavior of epoxy composites
Authors: Moehlenpah A. E. , Ishai O. , Dibenedetto A. T.
Published: December 2004

A crosslinked epoxy resin consisting of a 60/40 weight ratio of Epon 815 and Versamid 140 and composites of this material with glass beads, unidirectional glass fibers and air (foams) were tested in tension, compression and flexure to determine the effect of time and temperature on the elastic properties, yield properties and modes of failure. Unidirectional continuous fiber‐filled samples were tested at different fiber orientation angles with respect to the stress axis. Strain rates ranged from 10−4 to 10 in./in.‐min and the temperature from −1 to 107°C.

Isotherms of tangent modulus versus strain rate were shifted to form master modulus curves. The moduli of the filled composites and the foams were predictable over the entire strain rate range. It was concluded that the time‐temperature shift factors for tangent moduli and the time‐temperature shift factors for stress relaxation were identical and were independent of the type and concentration of filler as well as the mode of loading.

The material was found to change from a brittle‐to‐ductile‐to‐rubbery failure mode with the transition temperatures being a function of strain rate, filler content, filler type and fiber orientation angle, indicating that the transition is perhaps dependent on the state of stress.

In the ductile region, an approximately linear relationship between yield stress and log strain is evident in all cases. The isotherms of yield stress versus log strain rate were shifted to form a practically linear master plot that can be used to predict the yield stress of the composites at any temperature and strain rate in the ductile region. The time‐temperature shift factors for yielding were found to be independent of the type, concentration and orientation of filler and the mode of loading. Thus, the composite shift factors seem to be a property of the matrix and not dependent on the state of stress. The compressive‐to‐tensile yield stress ratio was practically invariant with strain rate for the unfilled matrix, while fillers and voids raised this ratio and caused it to increase with a decrease in strain rate. The yield strain of the composites is less than the unfilled matrix and is a function of fiber orientation and strain rate.
Cold rolling of polymers. 1 Influence of rolling on properties of amorphous polymer
Authors: Broutman Lawrence J. , Patil R. S.
Published: December 2004

Strips of ductile, amorphous thermoplastic polymers such as polycarbonates, acrylonitrile‐butadiene‐styrenes, polysulfones and polyphenylene oxides have been reduced in thickness by passing them through a metalworking rolling mill at room temperature. Properties of the rolled strips were studied as a function of the thickness reduction. In addition to rolling unidirectionally, cross rolling (biaxial rolling) was also studied using equal thickness reductions in each direction. The maximum thickness reduction (to — tf)100/to which could be achieved was approximately 60 per cent regardless of the polymer studied here. Stress‐strain curves, density changes, thermal stability, hardness and Izod impact strengths have been determined as a function of thickness reduction and sheet direction.
The effect of molecular weight and orientation on the sorption of n‐pentane by glassy polystyrene
Authors: Baird B. R. , Hopfenberg H. B. , Stannett V. T.
Published: December 2004

The effects of polymer molecular weight, molecular weight distribution, and orientation on the rate of relaxation‐controlled sorption of n‐pentane by glassy polystyrene were studied. The sorption follows Case II kinetics but for films which sorb slowly the sorption rate increases at relatively long times until sorption is sharply terminated. This rate increase may be explained by the development of dispersed microvoids within the unrelaxed film core. Overshoot of the equilibrium n‐pentane content occurs in sorption experiments in which accelerated sorption is pronounced.

The sorption rate is independent of polymer molecular weight and molecular weight distribution per se over a broad wrange of these parameters. Essentially identical vapor sorption kinetics were observed for well annealed polystyrene films of different molecular weights and distributions. Conversely, for vapor sorption by uniaxially oriented films and for liquid sorption by partially annealed films, high molecular weight film (1,880,000) exhibits greater sorption rates than low molecular weight film (ca. 200,000). These differences in rate are not due to molecular weight differences per se, but are a consequence of the dissimilar response of free volume and strain development for films of different molecular weight prepared with a given time‐temperature‐strain history.

Crazing of carefully annealed polystyrene films occurs during desorption of n‐pentane from partially saturated films. The depth of craze penetration reflects the point of advance of the discontinuous Case II sorption boundary.
Advances in instrumentation and technique of torsional pendulum and torsional braid analyses
Authors: Gillham J. K. , Roller M. B.
Published: December 2004

A torsional pendulum which operates throughout the temperature range — 180° ⇄ +650°C, and permits the examination of specimens which conform to ASTM standard D2236 is reported. The same apparatus is used for torsional braid analyses for which a composite specimen is prepared by impregnating a multifilament glass braid with a solution of polymer and thermally removing the solvent. A linear‐with‐angle no‐drag optical transducer which employs the linear transmission region of a pair of polarizers is described. The apparatus has been used for examining thermo‐hysteresis effects in polymers. Hysteresis can arise in polymers from physical time‐dependent phenomena such as crystallization ⇄ fusion, dry atmosphere ⇄ water vapor, annealing ⇄ cracking, and from chemical reactions. Thermally‐induced chemical reactions can be regulated so as to freeze out preferentially longer range relaxations, thereby extending the glassy state behavior to higher temperatures. A comparison of the thermomechanical behavior of a commercially available polyimide film and of a polyimideforming varnish is reported using torsional pendulum and torsional braid analyses.
The effect of hydrostatic pressure on the tensile properties of plastics
Authors: Pugh H. Ll. D. , Chandler E. F. , Holliday L. , Mann J.
Published: December 2004

The effect of hydrostatic pressure, up to 112,000 lb/in.2, on the tensile properties of four polymers is reported. The pressure soaking of polystyrene in castor oil had no significant effect on the material's residual properties when tested under ambient conditions. When tested under pressure polystyrene necked, like a metal, and exhibited a brittle ductile transition at 40,000 lb/in2. Between 40,000 to 112,000 lb/in.2 the tensile strength increased by about 30%. Young's modulus and yield strength were only slightly affected by pressure. Similar results were obtained for specimens sheathed to prevent possible plasticization of the polystyrene. Polymethylmethacrylate tested at 112,000 lb/in.2 failed just short of its instability point and with only a slight increase in Young's modulus. These amorphous polymers thus behaved under pressure in a generally similar manner to metals.

Pressure had a marked effect on the stress‐strain curves of two crystalline polymers polyethylene and nylon. Young's modulus and tensile strength were considerably increased and elongation decreased. Pressure inhibited ‘drawing’ of the materials. Deformation was restricted to a small necked region.
Pressure profiles in plasticating extruders
Authors: Donovan R. C.
Published: December 2004

The pressure distribution through the melting and melt zones of a plasticating extruder is discussed, and an analysis is described for predicting the pressure profile. In the stable melting zone, the pressure profile is calculated based on flow in the melt pool, and the pressure is strongly influenced by the flow of the solid bed of plastic. The solid bed flow is primarily determined by the polymer rigidity in the screw compression section. If the size (through a melting analysis) and the velocity (through a solid bed acceleration parameter) of the solid bed along the screw channel are reasonably approximated, the pressure profile is reasonably approximated by this analysis. Inaccurate representations of the size or velocity of the solid bed can yield inaccurate pressure profile prediction.

In the unstable melting region, the assumption of a complete melt yields reasonable pressure predictions. The introduction of these concepts into an extrusion model permits a more accurate prediction of the operating RPM of a given screw design in a given machine.
Plastic deformation of crystalline polymers
Authors: Peterlin A.
Published: December 2004

Under uniaxial tensile load, the plastic deformation of unoriented crystalline polymers first transforms the lamellae into a fibrous structure. Usually the drawing is inhomogeneous with a neck propagating through the sample. The higher the draw ratio, the higher the axial elastic modulus as a consequence of the larger fraction of taut tie molecules in amorphous layers connecting the crystalline blocks of each microfibril. As a consequence of the almost 1/(1 − α) times higher strain of amorphous layers under tensile load, the taut tie molecules are much more strained than the chains in crystal blocks. Hence, their contribution to elastic modulus is substantially higher than one would guess from their fraction β. This is more so in polyethylene with higher crystallinity (α = 0.8) than in nylon 6 with low crystallinity (α = 0.5). Even for the highest modulus polyethylene E = 70 GPa ∼ 0.3 × Ec, one needs less than 7.5 percent of taut tie molecules. The plastic deformation of the fibrous structure markedly enhances the number of interfibrillar tie molecules in nylon 6 and to a lesser extent in polyethylene and polypropylene. Homogeneous drawing without a neck transforms the whole sample into a fibrous structure rather uniformly so that for a long while one has the lamellar and fibrillar morphology side by side. The end effect on the structure obtained does not differ appreciably from inhomogeneous drawing with neck propagation. The drawing of polymers with a liquid crystal structure yields a highly aligned fibrous structure with very few chain folds and an exceptionally high elastic modulus and strength. But the axial connection of individual highly oriented and ordered domains is affected by a relatively small fiaction of tie molecules, and this is responsible for reduction of the elastic modulus below the value of the ideal crystal lattice.
Graft copolymers of polysaccharides with thermoplastic polymers. A new type of filled plastic
Authors: Bagley E. B. , Fanta G. F. , Burr R. C. , Doane W. M. , Russell C. R.
Published: December 2004

A series of starch graft copolymers and one cellulose graft copolymer were prepared containing 40‐50 percent synthetic polymer. The monomers used (styrene, methyl methacrylate, methyl acrylate, and butyl acrylate) were chosen to give grafted synthetic polymers with varying glass transition temperatures (Tg). These graft copolymers were extruded, in the absence of any added thermoplastic homopolymer, to give strong, continuous polysaccharide‐filled plastics which are biodegradable and which exhibit little or no die swell. Properties of plastics varied with the Tg of the thermoplastic portion. Starch‐g‐polystyrene and starch‐g‐poly(methyl methacrylate) were hard and brittle, while graft copolymers prepared from methyl and butyl acrylate were more flexible and leathery. The graft Uopolymers with lower Tg grafts required less torque and could be extruded at lower temperatures. In the methyl acrylate series, a graft copolymer prepared from gelatinized starch was more easily extruded than one prepared from granular starch, and addition of water produced a water‐filled extrudate of excellent quality. The surprising feature of these results is that the matrix polymers, starch and cellulose, are rigid, nonsoftening materials. Grafting of a thermoplastic polymer to these matrix polymers would not be expected to give an extrudable product. The results are explained as powder flow followed by fusion or sintering of the graft polymers under the temperature and pressure conditions in the die.
Nylon matting: A textile structure used for soil and civil engineering applications
Authors: Godehn D. J.
Published: December 2004

A new type of interlaced mat made of heavy denier nylon monofilaments has been developed, and has been under evaluation for the past few years. Due to its combination of unique properties—high strength, great porosity, chemical stability—it is finding uses in many varied applications. Its current greatest use is in soil erosion control, where the product, when placed on steep banks, traps soil particles caused by runoff water, thus preventing erosion and providing a good seed bed for grasses and other ground cover. Placed under turf and sods, the structure provides a porous, open structure which holds moisture and enhances root growth, while the mechanical strength of this material reduces packing of the soil, thus making a superior base for athletic fields and playgrounds. The product, its properties, and its applications are described.
Static and kinetic studies of polystyrene/poly(vinylmethylether) blends
Authors: Han C. C. , Okada M. , Muroga Y. , Mccrackin F. L. , Bauer B. J. , Tran‐Cong Q.
Published: December 2004

A systematic study of static and kinetic phase behavior of deuterated polystyrene/poly(vinylmethylether) blends is presented in this paper. The static properties are studied by the small angle neutron scattering techniques and the kinetics of phase decomposition are studied by the temperature jump light scattering; technique. This procedure provides detailed information about phase behavior with regard to both thermodynamics and kinetics.
Polyethylene‐polycarbonate blends: Interface modification, phase morphology and measurement of orientation development during cast film and tubular extrusion by infrared dichroism
Authors: Endo Shigeru , Min Kyonsuku , White James L. , Kyu Thein
Published: December 2004

The phase morphology and polymer chain orientation in polyethylene‐polycarbonte blends is investigated. A blend with a dispersed polyethylene phase was found to exhibit phase growth under quiescent conditions. Addition of a styrene‐(ethylene/butene) block copolymer controls the phase morphology and prevents phase growth. Melt spun tapes and tubular film have been prepared from polyethylene‐polycarbonate blends. Orientation of the crystallo‐graphic axes of the polyethylene and the chain axis of the polycarbonate were determined by infrared dichroism. The addition of polycarbonate to polyethylene is found to decrease chain orientation at the same drawdown stress.
Phase separation in crosslinked resins containing polymeric modifiers
Authors: Bucknall C. B. , Partridge I. K.
Published: December 2004

An analysis is made of the thermodynamic and kinetic factors affecting phase separation in blends of di‐, tri‐ and tetrafunctional epoxy resins, cured with either diamino‐diphenylsulphone (DOS) or with dicyanodiamide (Dicy), and modified with either poly(ethersulphone) (PES) or carboxyl‐terminated butadiene acrylonitrile (CTBN) rubber. The applicability and limitations of the solubility parameter approach in predicting compatibility in reactive blends are considered.
The effect of rubber particle size on the impact properties of high impact polystyrene (HIPS) blends
Authors: Hobbs S. Y.
Published: December 2004

The impact fracture of nominally identical high impact polystyrene resins having different and well‐characterized rubber particle size distributions is discussed. A numerical model for craze termination is presented and its predictions are compared with experimental data. An alternative explanation for the observed effect of particle size on fracture energy is considered.
Flexural properties of moldings of rigid polyurethane made by reaction injection molding
Authors: Iida Makoto , Gotoh Masao , Yokono Hitoshi , Miyano Yasushi
Published: December 2004

Flexural properties of moldings made by Reaction Injection Molding (RIM), which are structural foams consisting of high density skin and low density core, were investigated by three‐point bending tests. Two failure modes were observed in bending tests of the moldings made by RIM, and they are classified as follows according to the density ratio of skin layer to core layer: the opposite side of the skin layer to which load was subjected failed by tensile stress: and the same side of the skin layer to which load was subjected failed by compressive stress, causing wrinkling or buckling. Then the conventional composite beam theory was applied to the former failure mode and Hoff s buckling theory to the latter, and equations were derived to predict the flexural properties of the structural foams, which involved buckling from the flexural properties of solid construction. In addition, it has been shown that there exists a density distribution that maximizes the flexural strength of the moldings made by RIM with a given overall density. The results obtained here should be useful to the optimum structural design of moldings made by RIM.
Surface tension and surface entropy for polymer liquids
Authors: van Ness K. E.
Published: December 2004

A cell theory for the prediction of the surface tension of polymer liquids is modified to include an entropic effect due to molecular asymmetry. Also considered is the extent of the effect of the preservation of connectivity in the vicinity of the surface upon the potential energy zero term due to missing nearest neighbors of orders greater than one. Theory and experiment are in good agreement without an adjustable surface parameter.
Arylmethyl sulfones: A new class of photoacid generators
Authors: Novembre A. E. , Hanson J. E. , Kometani J. M. , Tai W. W. , Reichmanis E. , Thompson L. F. , West R. J.
Published: December 2004

The X‐ray and deep UV radiation response is described for resist systems consisting of poly(4‐tert‐butoxycarbonyloxystyrene‐co‐sulfur dioxide) PTBSS combined with an arylmethyl sulfone. A 2:1 4‐tert‐butoxycarbonyloxystyrene (TBS): sulfur dioxide (SO2) resist has been found to function as a highly sensitive, 1.4 nm X‐ray, single‐component, chemically amplified resist. The same resist, however, exhibits reduced sensitivity to 0.8 nm X‐rays and deep UV (248 nm) radiation. Improvement in 0.8 nm X‐ray sensitivity is achieved by the addition of 12 mol% bis(3,4‐dichlorobenzyl) sulfone (DCBS) to the 2:1 TBS:SO2 resist. For this two‐component resist formulation, the 0.8 nm X‐ray sensitive improved from >375 to 125 mJ/cm2. Similarly, the sensitivity of the 3:1 TBS:SO2 copolymer to deep UV radiation improves to 40 mJ/cm2 with addition of 10 mol% DCBS. Sulfones, such as DCBS, provide two‐component resist formulations capable of <0.5 μm resolution.
Liquid crystallinity: Medium effects on photopolymerization rates
Authors: Hoyle C. E. , Kang D. , Chawla C. P. , Griffin A. C.
Published: December 2004

Ordering of the medium in which free radical polymerization is conducted can, under appropriate circumstances, alter the kinetics of the chain‐growth process, resulting in enhanced rates. Since in many systems medium changes occur at higher conversion, it is important to take into account any alterations in the polymerization rate induced by such phenomena. We have found that exotherms initiated by individual laser pulses can be useful in identifying and providing detailed information concerning rate acceleration in liquid crystalline systems. From measurements of the pulse intensities in the sample cell, estimates of the quantum efficiency and kinetic chain length have been made directly from the integrated areas of the exotherm curves. Recent refinements in our sample geometry have allowed us to generate reproducible efficient data as a function of the degree of conversion and order in the polymerization medium.
Novolak design concept for high performance positive photoresists
Authors: Hanabata Makoto , Oi Fumio , Furuta Akihiro
Published: December 2004

Novolak resins have been optimized for high performance positive photoresists. Low molecular weight novolak resins are the key components for improving resolution capability, sensitivity, and heat resistance of positive photoresists. Various phenolic compounds (monomers) and oligomers of metacresol novolak resins were evaluated as low molecular weight components. It was found that phenolic compounds that have moderate hydrophobicity and azocoupling capability with diazonaphthaoquinone compounds greatly improve positive photoresist performance. This is explained in terms of the Stone wall model for positive photoresist development.
The synthesis and characterization of novel 2‐nitrobenzyl sulfonate photo‐generators of acid
Authors: Houlihan F. M. , Neenan T. X. , Chin E. , Reichmanis E. , Kometani J. M.
Published: December 2004

Methodology was developed for the synthesis of novel 2‐substituted o‐nitrobenzyl chromophores, which were derivatized as the tosylate esters. The thermal stabilities of these new tosylates fell within the range predicted from an empirical model. Lithographic sensitivities of deep UV resists made from these new esters and poly(4‐(tert‐butoxycarbonyloxy)styrene‐sulfone) ranged from 45 to 90 mJ/cm2.
Conducting polymers as lithographic materials
Authors: Angelopoulos Marie , Shaw Jane M. , Lee Kam‐Leung , Huang Wu‐Song , Lecorre Marie‐Annick , Tissier Michel
Published: December 2004

Conducting polyaniline is found to be suitable for several lithographic applications. With the use of onium salts, polyaniline is made radiation sensitive and shown to be a high resolution conducting photo and electron‐beam resist. Conducting lines of 0.25 μm have been patterned with e‐beam irradiation. Thin films of conducting polyaniline are found to be effective discharge layers for e‐beam lithography. Insulating resist systems charge during e‐beam exposure, which results in pattern displacements. When polyaniline is used as a conducting layer below the imaging resist, no pattern displacements are observed. Polyaniline is also shown to eliminate charging during the high resolution inspection and dimensional measurements of X‐ray and optical masks by scanning electron microscopy (SEM) when used as a coating on top of the mask. In addition, polyaniline can be used for electrolytic and electroless type metallization processes.
ARCOR, a new photolithography technique with antireflective coating on resist
Authors: Tanaka Toshihiko , Hasegawa Norio , Shiraishi Hiroshi , Okazaki Shinji
Published: December 2004

The multiple interference effect is one of the major causes of the fluctuation in critical dimension control (CD) and in mark detection for alignment. Suppressing this effect is critical for future photolithography. We propose a new photolithography technique called anti reflective coating on resist (ARCOR), which improves linewidth accuracy and overlay accuracy by suppressing multiple interference. ARCOR consists of relatively simple processes: A clear antireflective film is spun onto the resist prior to the mark detecting for alignment and exposure. The film is subsequently removed and the resist developed in the conventional way. ARCOR differs from ARC, which suppresses the reflection at the resist/substrate interface. ARCOR suppresses the reflection at the air/resist interface. ARCOR allows mark detection and exposure without light intensity‐loss and multiple interference. The experiments mainly examine polysiloxane and perfluoroalkylpolyether as ARCOR materials. It is shown that linewidth accuracy can be improved from 0.3 to 0.03 μm. The signal‐to‐noise ratio of the alignment signal is drastically improved, and the overlay error is about half that of the conventional method. ARCOR is also effective for directly measuring the reflectivity at the resist/substrate interface, which is a key parameter of the multiple interference effect and the halation. Using ARCOR and a thin resist film, the measured ratio of reflected light to incident light indicates the reflectivity at the resist/substrate interface. Because, the probe light does not reflect off the resist surface and the intensity‐loss at the resist surface is suppressed. With perfluoroalkylpolyether film, the measurement error is ∼ 1.5%.
Dry‐developed organosilicon resists for 193‐nm excimer laser lithography
Authors: Kunz R. R. , Horn M. W.
Published: December 2004

Irradiation of certain organosilicon polymers with a 193‐nm excimer laser forms a latent image that contains increased amounts of oxygen. Patterning is achieved by dry development in an HBr plasma, where the oxidized polymer etches more slowly than the unexposed areas. With these polymers as the top layer in a bilayer resist scheme, 0.2 μm resolution has been demonsrated and resist sensitivities less than 50 mJ/cm2 have been achieved. Three classes of organosilicon layers have been investigated: polysilynes; polysilanes, in particular poly(phenylmethyl) silane; and a plasma‐deposited polymer derived from tetramethylsilane (PPTMS). The PPTMS, when used with plasma‐deposited planarizing layers, opens the possibility of an all‐dry, cluster‐tool‐compatible lithographic cycle.
Selected equipment, materials, and process interactions in a surface‐imaging process
Authors: Garza César M. , Solowiej Eric J. , Boehm Mark A.
Published: December 2004

The advantages of surface‐imaging photoresist processes have been well documented; it has shown to have greater resolution, wider focus budget, and less sensitivity to topography and reflections from the substrate. The DESIRE process (Diffusion Enhanced Silylated Resist) is a good example of a surface‐imaging process. In previous papers we have described the characterization of this process in a lab environment, discussed some of the issues involved in the implementation of this process in a manufacturing environment, and more recently presented results from its implementation in a dynamic random memory, DRAM, manufacturing environment. A large of knowledge must be acquired and disseminated in the process of implementing a new technology in a manufacturing environment. This is particularly true in the semiconductor industry because of the large and complex interactions that exist between the process and the electronic characteristics of the devices. Even within the same process, complex interactions between the different steps can take place. Such is the case with the DESIRE process. Over the past few years a great deal of “know‐how” has been acquired in the course of implementing this technology in a DRAM wafer fab of Texas Instruments in Dallas, Tex. We present here two selected cases where such complex interactions have been investigated: (1) radiation damage that might take place during the dry‐development step of this process, and (2) the effect of the equipment and material on the electrical discharge, or arcing, during dry‐development.
Synthesis and characterization of a low stress photosensitive polyimide
Authors: Nader Allan E. , Imai Kazunori , Craig John D. , Lazaridis Christina N. , Murray Daniel O. , Pottiger Michael T. , Dombchik Stephen A. , Lautenberger William J.
Published: December 2004

Use of polyimides with thermal coefficients of expansion comparable to that of the underlying substrate is critical to achieving low stress in microelectronic packaging applications. Photosensitive polyimides are finding increased use because of their significant reduction in device processing steps. A negative working photosensitive polyimide, based on the BPDA/PPD backbone, has been synthesized that incorporates these key features. The polyimide exhibits excellent photosensitivity and lithographic behavior, while retaining many thermal and physical properties of the polymer framework.
Pre‐imidized photoimageable polyimide as a dielectric for high density multichip modules
Authors: Cech Jay M. , Burnett Andrew F. , Knapp Lisa
Published: December 2004

Issues relating to the fabrication of complex multichip modules were investigated from a manufacturability perspective. The use of a preimidized photosensitive polyimide reduces the number of processing steps, thus making it a desirable dielectric material. Factors influencing the polyimide resolution, stress, and feature profile were studied both by experimentation and modeling. Thermal cure cycles for polyimide baking were optimized for solvent resistance, polyimide mechanical properties, and process throughput. Studies were also done on polyimide interactions with metal depositions, including adhesion and polyimide surface damage. Results of this research are shown as embodied in a fabricated 1.4 Gbit/s optical transceiver multichip module.
Die Spaltungserscheinungen in der Trimethylen‐oder Cyklopropangruppe
Authors: Kötz A.
Published: December 2004

Die Beständigkeit des Dreiringes im Trimethylen verringert sich bei Einführung einer Alkylgruppe, vergrößert sich bei Einführung einer Karboxylgruppe.
Einwirkung von Oxalylchlorid auf Resorcin
Authors: Mikšić Josip
Published: December 2004

Durch die Einwirkung von Oxalsäure auf Resorcin entstehen im allgemeinen Pyronderivate, oder besser: Derivate des 2,7‐Dioxyxanthons. Für alle diese Produkte ist ihr grünes Fluorescenzvermögen wie auch ein bestimmtes, bei etwa 500 μμ absorbierendes Spektrum kennzeichnend. Die bisher ausgeführten Reaktionen verliefen in zwei Richtungen: entweder zersetzte sich die Oxalsäure, und das entstandene CO2 reagierte mit 3 Mol Resorcin, oder es trat keine Zersetzung der Oxalsäure ein. In beiden Fällen entstanden jedoch Dioxyxanthonderivate. Im letzten Falle regeneriert sich beim Schmelzen der Produkte mit NaOH die Oxalsäure.
Einwirkung von Ferrocyanwasserstoffsäure auf bicyclische Terpene: Eine neue Partialsynthese von Terpenbasen und ‐alkoholen
Authors: Stephan K. , Hammerich Th.
Published: December 2004

Die Einwirkung der Ferrocyanwasserstoffsäure auf bicyclische Terpene führte zu interessanten Ergebnissen, die im folgenden kurz zusammengefaßt sind:

Die bicyclische Terpene, Camphen, α‐Pinen und No‐pinen vereinigen sich mit der Ferrocyanwasserstoffsäure unter Bildung fester, sehr beständiger Verbindungen nach folgender Gleichung:

Diese Verbindungen lassen sich nur spalten, wenn sie mit überschüssiger Lauge mehrere Stunden bei etwa 160° (im Autoklaven) erhitzt werden. Es entstehen dabei (neben Terpenen) Alkohole und Basen:

aus Camphen: Camphenhydrat und Isoborneol (neben Camphen) sowie Isobornylamin;

aus α‐Pinen : α‐Terpineol (neben Limonen) sowie Isobornylamin, verunreinigt mit Isofenchylamin;

aus Nopinen: α‐ Terpineol (neben Limonen), sowie Isofenchylamin.

Es wird angenommen, daß die Alkohole und Basen von verschiedenen isomeren Verbindungen der Ferrocyanwasserstoffsäure sich ableiten: die Alkohole entstehen durch Verseifung wahrer Ester der Ferrocyanwasserstoffsäure, die Basenbilden sich aus Verbindungen, in denen der Isobornyl‐ bzw. Isofenchylrest an den Stickstoff der Cyangruppen gebunden ist. Eine Trennung der Anlagerungsverbindungen ist bisher noch nicht gelungen.

Der aus Camphen entstehende Isobornylester zeigt übrigem die für alle Ester des Isoborneols charakteristischen Isomerisationserscheinungen.

Von der Ferrocyanwasserstoffsäure werden ferner die Autoxydationsprodukte des Pinens und das bei der Hydratation zu Terpinhydrat intermediär entstehende Terpineol als leicht spaltbare Oxoniumsalze gebunden.
Über die Einwirkung schwefligsaurer Salze auf aromatische Amino‐ und Hydroxylverbindungen. 14. Mitteilung. Über Umlagerungen von Azofarbstoffen, insbesondere über die Umwandlung von Azofarbstoffen in Küpenfarbstoffe
Authors: Bucherer Hans Th. , Rauch Max
Published: December 2004

Die Versuche, durch Kondensation von Orange II mit p‐Phenylendiamin einen „Semidin”︁ ‐artigen Azofarbstoff: magnified image zu erhalten, führten nicht zum Ziel. Vielmehr zeigte sich, daß die Kondensation, im Gegensatz zu der analogen mit Phenylhydrazin: magnified image unter gleichzeitiger weitgehender Veränderung des Azofarbstoffes erfolgt. Die dabei erhaltene farbige Verbindung, deren Konstitution nicht aufgeklärt wurde, zeigt den Charakter eines verküpbaren Farbstoffs.
Dielektrische Eigenschaften der ätherischen Öle im Zusammenhang mit deren Konstitution und ihren Bestandteilen
Authors: Kowalew T. G. , Illarionow W. W.
Published: December 2004

I. Die als markanteste Funktion der Konstitution des Stoffes erscheinenden dielektrischen Eigenschaften charakterisieren ihn von allen physikalischen Eigenschaften am besten. Dabei sind die Grenzen der numerischen Werte dieser Konstante bei den ätherischen Ölen ziemlich groß, so daß einer großen Anhäufung von Daten in einem kleinen Intervall vorgebeugt wird. Es werden ferner die breiteren Schwankungen dieser Konstante, die bei gleichen Ölen beträchtlicher sein sollen als die des spez. Gewichts, die Möglichkeit bieten, die Menge dieser oder jener in dem Öle enthaltenen Komponenten leicht zu bestimmen.
Über eine Räumlich‐energetische Ursache der Komplexbildung
Authors: Beck G.
Published: December 2004

1. Als Überspannung oder Hypertension der Moleküle wird ein Zustand bezeichnet, bei dem die Moleküle aus den Elementen unter starker Kontraktion, aber relativ geringer Energieabgabe entstanden sind. Die Valenzelektronen befinden sich daher in einem mehr oder weniger hochangeregten Zustand und suchen durch Eingehen neuer, komplexchemischer Reaktionen in einen stabileren Zustand überzugehen.