摘要:

Developing a blood-compatible material means not merely synthesizing a suit- able polymer, which [l] is nontoxic, sterilizable, noninflammatory with no adverse immune response, easily fabricable and nondegradable with stable mechanical strength for a prolonged period of time, and giving it a form of a prosthesis, but it is also equally important to understand polymer surface/blood component interactions at the interface, since surface-induced [2] thrombosis and embolism are the main obstacles to the use of nonbiological materials. Once a foreign surface comes in contact with blood, it is immedi- ately altered by the adsorption of plasma proteins, and the nature of the pro- tein adsorbed may affect the fate of material toward blood compatibility. Certain proteins [3,4], e.g., albumin, discourage platelet adhesion, but others, like y-globulins and fibrinogen, encourage platelet adhesion and enhance fur- ther thrombosis. Therefore, such initial events, which are dependent on the physicochemical nature of the surface, play a major role for the acceptance or rejection of the material. Adjusting these physicochemical parameters to cer- tain processing variations is also an important consideration [5].

ISSN:0360-2559    

DOI:10.1080/03602558408070046

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Because of the high viscosity (>l00 N·s/m2)that is characteristic of polymer melts, a significant amount of viscous heat can be generated in flows that are subjected to high shear rates. Moreover, polymers have low thermal conduc- tivities, insuring that high shear operations result in an increase in the tempera- ture of the polymer. Because polymers have limited thermal stabilities, processing techniques are limited to low shear operations or regions of limited high shear. Such limited high shear regions usually involve the flow of a thin polymer melt over a large surface area for maximum heat transfer.

ISSN:0360-2559    

DOI:10.1080/03602558408070047

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

With the increasing demand for plastics as replacements for such conventional materials as glass, metal, and wood in a wide variety of applications, there have been more and more industrial processes in which polymer melts are extruded through dies of complex cross section to form the final product. The shape of these dies and the pressure losses through them are important factors in pre- venting flow defects and controlling the quality of the end product. Predic- tions of pressure losses through dies of complex cross section have not been as popular a subject in the literature as flow through circular cross-sectional dies.

ISSN:0360-2559    

DOI:10.1080/03602558408070048

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Biomedical devices are used for prosthetic, diagnostic, therapeutic, and storage applications. They include materials of synthetic and natural origin in contact with blood, tissue, and biological fluids. These devices are mainly categorized as follows [1].

ISSN:0360-2559    

DOI:10.1080/03602558408070049

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

One of the basic technical and economic problems in the manufacture of plas- tics is improving the rate of production without adversely affecting the surface of the product. When the rate of extrusion is gradually increased above the critical value of rate of shear, γ ≥ γc(or the corresponding critical shear stress σ12≥ σ12, c), the extrudate becomes rough, distorted, and fractured.), The phenomenon, known as “melt fracture”, hasbeen investigated by many authors during the last 30 years, e.g., see Refs. 14, and reviewed by others [5–9]. Melt fracture is observed for all polymers and plastics. However, several types of distortion with such colorful names as sharkskin and orange peel have been observed for one but not for another extruded material. In this article we re-restrict ourselves to the types of distortions observed for linear, high-density polyethylene (HDPE).

ISSN:0360-2559    

DOI:10.1080/03602558408070050

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

For several years, elastomeric sheet molding compound (SMC) additives have been considered for automotive exterior panel applications where shrink control, improved surface appearance, and impact improvement are desired. Shell has designed a special styrene-butadiene (S-B) copolymer system, Kraton GX-1855, for this application. We now report the results of our morphological work in this area.

ISSN:0360-2559    

DOI:10.1080/03602558408070051

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Impact behavior of glass and carbon fiber composites has been studied in some detail both with respect to methodology of testing and to interpretation of the influence of fiber orientation and viscoelastic resin properties on the measured fracture energies [14]. Most authors use some variation of the Charpy drop- weight test in which the impacted beam specimen is placed between two anvils. It is known that when the ratio of the span between the anvils to specimen thickness is small, e.g., less than 10, shear effects are very important. Most authors, therefore, test specimens at a larger span-to-thickness ratio, usually 16 and above. At these ratios the failure induced will be essentially a tensile fail- ure, dominated by fiber orientation and volume.

ISSN:0360-2559    

DOI:10.1080/03602558408070052

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0360-2559    

DOI:10.1080/03602558408070045

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor