摘要:

AbstractIt is proposed that titanium‐derived coupling agents react with free protons at the inorganic interface to form organic monomolecular layers on the inorganic surface, which causes inorganic/organic phase compatibilization resulting in new composite property, catalysis, adhesion, and rheology performance standards. Processing techniques and rheology effects using titanates are discussed. The injection pressures of CaCO3, carbon black filled polystyrene, and glass‐fiber, talc‐filled poly(phenylene sulfide) are shown to be reduced 50 percent by use of cumyl phenyl type titanate. Adhesion effects are discussed in many composites such as epoxy/aluminum, acrylic/slate, carbon fiber/polyester, etc., followed by data showing significant property improvements in 1/16 inch milled glass fiber and Wollastonite RRIM urethane, printed circuit boards and amide and anhydride cured aramid fiber‐reinforce

ISSN:0032-3888    

DOI:10.1002/pen.760241802

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe structural modifications and the changes in crystallinity of poly(phenylenesulfide) (PPS) during high‐pressure molding and curing have been investigated as a function of pressure and temperature using wide‐angle X‐ray scattering (WAXS), infrared absorption (IR) and scanning electron microscopy (SEM). It has been found that the crystalline content of the molds varies with applied pressure asPαwhere α is 1.5. Major changes in the IR spectra are found in the range of 800 to 600 cm−1and attributed to structural modifications which have also been noted in the scanning electron micrographs. These various results have been mainly explained on the basis of plastic deformation and flow during the high‐pressure mold

ISSN:0032-3888    

DOI:10.1002/pen.760241803

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractA series of stretch‐blow molded poly(ethylene terephthalate) bottles were investigated using measurements of birefringences (in plane and out of plane) and wide angle x‐ray diffraction (WAXS) pole figures. Both bottles prepared in our laboratories and commercial bottles were investigated. Birefringences Δn13and Δn23of inside and outside surfaces of bottles were determined as a function of position along the length of the bottle (1‐bottle axis, 2‐hoop direction, 3‐thickness direction). The Δn13, Δn23 for the inside surface of the bottles were found to be greater than those for the outside surface indicating heterogeneity through the thickness of the bottles. The WAXS studies indicate that the benzene rings in the polymer align parallel to the bottle surface. The chain axis in crystalline regions exhibit orientations close to equal biaxial orientation. Both Δn13and Δn23increased with inf

ISSN:0032-3888    

DOI:10.1002/pen.760241804

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractA new macrokinetic equation of the autocatalytic type is proposed to describe the polymer crystallization process. The derived equation is compared with the known Avrami equation. It is shown to be consistent with the results of isothermal experiments.

ISSN:0032-3888    

DOI:10.1002/pen.760241805

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe isothermal macrokinetic equation of polymer crystallization has been generalized to cover nonisothermal situations as well. The process of nonisothermal crystallization of poly(caproamide) has been studied experimentally. It is shown that the macrokinetic equation of the autocatalytic type can be used to solve both direct and inverse problems of nonisothermal polymer crystallization. Use of the inverse approach has made it possible to establish the value of the constants of the new kinetic equation. The general statement of the problem of nonisothermal crystallization of polymers in an inhomogeneous temperature field is considered. Inhomogeneous temperature and conversion fields have been calculated for model products of different sizes and configurations.

ISSN:0032-3888    

DOI:10.1002/pen.760241806

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractRecently we developed a nonlinear viscoelastic constitutive model which called the Phases Model (PHM) [10]. The main advantages of the PHM over existing nonlinear viscoelastic models are that it lends itself to simple, straightforward calibration of the material functions, and that it is naturally suitable to step‐by‐step computer simulation. In this paper we apply the PHM to two dimensional (2‐D) situations. To this end, we've developed a 2‐D finite difference code in cylindrical geometry which is based on the PHM. We demonstrate the validity of our modeling by applying the code to a 2‐D set‐up developed for this purpose. The 2‐D specimen is in the form of a disc of the test material compressed between two rigid metal anvils by a velocity‐controlled Instron machine. We monitor the response of the viscoelastic disc in terms of the overall axial force history, and the axial stress component at the disc center. We get good agreement between theory

ISSN:0032-3888    

DOI:10.1002/pen.760241807

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractBy the use of water absorption data (rate and equilibrium), the diffusivity of distilled and salt water through Neoprene, styrene‐butadiene, and ethylene‐propylene‐diene elastomers was predicted. Activation parameters were calculated from the Arrhenius plots and were used to calculate heats of solution (all negative). Solubility coefficients (S) were calculated from permeability (P) and diffusion (D) coefficients. For all materials salt water showed a lowerDthan distilled water but a higher

ISSN:0032-3888    

DOI:10.1002/pen.760241808

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractA chemiluminescence multi‐sample apparatus and method are described for determining polymer stability by measuring the intensity of the light emitted during thermal oxidation. Depending on the nature of a material analyzed the experiments are performed either under O2atmosphere at a constant temperature or under N2atmosphere at a constant heating rate. In the former case applicable to polypropylene (PP) and acrylonitrile‐butadiene‐styrene copolymers (ABS), parameters such as induction time and oxidation rate can be evaluated. In the latter case applicable to nylon and polyethylene terephthalate (PET), the extent of oxidation in a certain temperature region can be evaluated by measuring the area under the intensity of light—temperature curve. Along with providing a great deal of knowledge on thermal oxidative stability, the chemiluminescence approach gives the additional information concerning polymer quality. The appearance of the low‐temperature pulses on the chemiluminescence curve observed before the onset of autocatalytic oxidation is associated with the history and processing of the sample and with the natural aging of th

ISSN:0032-3888    

DOI:10.1002/pen.760241809

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe deformation recovery at room temperature of a polycarbonate after large tensile deformation and subsequent stress relaxation is measured as a function of time. The effect of the main parameters which affect the amount of recovered deformation is analyzed. This suggests a plot of the recovery versus time curves by means of proper coordinates which allow shifting of all curves towards a single master curve, thus indicating that most of the phenomena involved in the recovery process are taken into account.

ISSN:0032-3888    

DOI:10.1002/pen.760241810

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

ISSN:0032-3888    

DOI:10.1002/pen.760241801

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY