ISSN:0730-6679    

DOI:10.1002/adv.1985.060050101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1985.060050102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe mechanical properties of test specimens from centrally injection‐molded disks made of short glass fiber‐reinforced polyamide 6,6 were tested under conditions of monaxial and biaxial constant strain rate and impact stress. In addition, the disposition of the glass fibers in the molded parts was established by optical microscopy and roentgenographic methods. Image analysis was used to measure the reduction of mean fiber length caused by processing and to determine quantitatively the fiber orientation. The possible existence of a correlation between fiber orientation data, as obtained from photomicrographs of polished sections, mechanical properties, and fracture characteristics is discus

ISSN:0730-6679    

DOI:10.1002/adv.1985.060050103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1985.060050104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe Couchman equation for miscible blends has been extended. The new semiempirical equation,w1ln(Tg/Tg1) +kw2ln(Tg/Tg2) = 0, is simple to use and flexible enough to provide an adequate description of Tgvariation with composition for miscible, semimiscible, and immiscible blends. The equation parameter k indicates the blend miscibility.

ISSN:0730-6679    

DOI:10.1002/adv.1985.060050105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractSamples of commercial LDPE, HDPE, LLDPE, and their blends were tested in the steady state (rotational and capillary), dynamic, and extensional modes. The steady state data at low rates of deformation followed the dynamic viscosity, η = η′, and at higher rates the complex viscosity η ≃ η*. In elongational tests strain hardening was observed for LDPE and some for HDPE. There was no strain hardening in flow of a standard LLDPE, and the equilibrium extensional viscosity η ≃ 3η′ in full range of deformation rates. In blends with ultrahigh molecular weight PE and with LLDPE strain hardening and an increase of the maximum strain at break, εb, were found. Some newer types of LLDPEs and their homologous blends show the strain hardening behavior. A brief review of the methods of measurement of the flow properties of polyethylene (PE) melt is provided. The text is divided into three parts: (1) types of melt flow; (2) comparative rheology of polyethylenes; and (3) linear low density polyethylene (LLDPE) blends. In the first part, the methods of measurement and correlation between the measured values are discussed. The steady state shearing, dynamic deformation, and uniaxial extensions are considered. In the second part rheological behavior of the three principal types of PEs, low density PE (LDPE), high density PE (HDPE), and LLDPE are presented. In part 3, the flow of four different types of LLDPE blends

ISSN:0730-6679    

DOI:10.1002/adv.1985.060050106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe bubble growth in polymeric fluids under nonisothermal conditions has been molded using the viscoelastic constitutive equation of Leonov incorporating the diffusion of gas from the melt to the bubbles. The gas diffusion seems to be the primary mechanism of bubble growth. The theoretical predictions for Han and Yoo's isothermal experiment compare well with the experimental data. The bubble size distribution in a foam molded specimen of NORYLRegistered trademark of the General Electric Company.resin has also been determined by measuring the bubble size from micrographs. Theoretical predictions for this specimen are in reasonable agreement with the data. A parametric study indicates that the blowing agent concentration has the strongest influence on the final bubble size, followed by melt and the mold temperature.

ISSN:0730-6679    

DOI:10.1002/adv.1985.060050107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1985.060050108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY