摘要:

AbstractIn (1), Narisawa and Takemori examined the physical interpretations and some experimental techniques of theJ‐Integral (ASTM E813‐81) as applied to toughened polymers. Their results and conclusions are reexamined and discussed in terms of recent developments inJtest

ISSN:0032-3888    

DOI:10.1002/pen.760302102

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

ISSN:0032-3888    

DOI:10.1002/pen.760302103

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

摘要:

AbstractA negative deep UV resist, XP 8843 (Shipley Co.),Since this paper was written the name of this resist has been changed from XP 8843 to SNR 248‐10.has been made positive by the addition of 1,2,4‐triazole. This is achieved by exposing the resist in the presence of the additive thereby inhibiting the crosslinking reaction. After exposure the additive is removed by heating under a vacuum. Unexposed areas of the resist may then be exposed and the resist crosslinked under normal processing conditi

ISSN:0032-3888    

DOI:10.1002/pen.760302104

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

摘要:

AbstractAn easy to use, spreadsheet based, mathematical model for drying of strand cut polymer pellets has been developed and experimentally verified. This particle‐scale model is based on internal mass‐transfer controlled diffusion in the pellet. Examples of its usage in correlation and prediction of the effects of the drying‐gas temperature, humidity, and pellet dimensions are presented. Application of the particle‐scale model to the design of a countercurrent hopper drier is discussed. Even though examples are limited to water removal from poly(bisphenol‐A)carbonate pellets, the model is general and may be used for the removal of other non‐solvating low‐concentration molecules from polymers with isotrop

ISSN:0032-3888    

DOI:10.1002/pen.760302105

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

摘要:

AbstractThe irreversible absorption of macromolecules on to solid filler particles during mixing in the melt is investigated. The molecular weight and concentration dependence of the absorbed layer thickness are evaluated and the chemical and morphological nature of the irreversibly absorbed polymer (bound polymer) are determined. It is found that the thickness of the bound polymer is not only dependent on the filler concentration but also dependent on polymer molecular weight. Bound polymer in high density polyethylene/colloidal silica systems is more amorphous and contains higher concentration of oxidation products (which are induced by a mechanochemical reaction during mixing) when compared with free polymer. As a result of bound polymer formation, flow induced crystallization and polymer entrapment during mixing, a phase separation between bound polymer and free polymer takes place which eventually leads to a liquid to solid phase inversion when the phase volume of the solids exceed a critical value under isothermal conditions. If the mixing is continued after phase inversion, the particle size of the newly formed powder is reduced and particle size distribution, is narrowed. This process of phase inversion and subsequent size reductions are termed as crumbling which can take place at filler concentrations well below the expected maximum packing fraction of solids, if the filler particle size is small and/or the molecular weight of the polymer is high. Crumbling phenomena are utilized in the agglomeration of fine powders and microencapsulation of solids and/or liquids.

ISSN:0032-3888    

DOI:10.1002/pen.760302106

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

摘要:

AbstractMonodisperse methyl methacrylate grafted latex rubber (MMA‐g) particles (0.12‐0.13 µm) have been used for the impact toughening of a series of styrene‐acrylonitrile (SAN) copolymers of variedANcontent. It was found that theMMA‐gparticles are most effective in tougheningSANscontaining about 25 to 34%AN.Mechanical properties, interphase adhesion, mechanical dilatometry, and phase morphology by transmission electron microscopy were determined on blends containing 20‐30% rubber. Also, the miscibility range ofSANsand poly(methyl methacrylate) (PMMA) graft was considered in attempting to analyze the relationships between the mechanical properties and the characteristic features of the blends. Issues relating the impact strength and deformation mechanisms, interphase adhesion, and particle morphology are discussed. It appears that the high impact strength of some of the blends may be caused primarily by certain morphological features such as particle clustering or small interparticle distances. Thus, craze initiation, shear yielding, and significant matrix deformation may all contribute to the overall ductility of

ISSN:0032-3888    

DOI:10.1002/pen.760302107

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

摘要:

AbstractThe flow pattern within a partially intermeshing co‐rotating twin‐screw extruder is three dimensional and extremely complex. In order to simplify the problem, a slice perpendicular to the axis of the twin‐screw extruder has been considered for flow analysis as a two‐dimensional or a quasi‐three‐dimensional problem. The flow in this slice may be considered to consist of a nip region (located between the two screws) and a translation region in which the movement of the material is very similar to the one found in single‐screw extruders. The flow in these two regions have been studied separately. This paper presents the numerical and experimental results of the nip region study. The flow division in the nip region has been quantified and results are presented in terms of a flow division ratioXf. The flow field patterns have also been obtained. Newtonian as well as non‐Newtonian behavior has been investigated. The influences of such factors as (i) the geometry (the radius of the barrel, radius of the screw, distance between the two screws), (ii) the material properties (the power‐law index for shear rate dependent viscosity), and (iii) processing conditions (the screw speed), have

ISSN:0032-3888    

DOI:10.1002/pen.760302108

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

摘要:

AbstractCrack healing in poly(methyl methacrylate) (PMMA) by methanol treatment at 40°C–60°C has been investigated. It is found that the methanol treatment reduces the glass transition temperature in PMMA. Crack healing only occurs at an operating temperature higher than the effective glass transition temperature. There are two distinctive stages for crack healing based on the recovery of mechanical strength. The first stage corresponds to the progressive healing due to wetting, which has a constant crack closure rate at a given temperature. Immediately following the first stage, the second stage corresponding to diffusion enhances the quality of healing behavior. The surface morphologies obtained during healing and after fracture tests confirm these two stages. By comparing the fracture stress with the fractography, the fracture surface for stage I of crack healing is coplanar to the original crack surface. On the other hand, the original crack surface is destroyed in stage II of crack healing. It occurs in the region incorporating the original healed surface and appears to be like the Virgin fracture surface. It is also found that the tensile fracture stress of PMMA treated by methanol can recover to that of the virgin material. In addition, it is interesting to find that after sustained methanol treatment, the “snake bone” phenomenon on the fracture surface

ISSN:0032-3888    

DOI:10.1002/pen.760302109

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

摘要:

AbstractThis is a study on the rheological properties and packing efficiency of a fluid suspension, composed of a mixture of two dissimilar particulate species. A generalized analytic expression for the viscosity of the blend is first developed, and then utilized to derive quantitative ways of maximizing the fluidity and optimizing the filling capacity of the composite system. These, results are compared with earlier experimental and theoretical findings, and with the rheological measurements performed in the course of this work on a series of calcium carbonate‐carbon black suspensions in poly‐dimethylsilox

ISSN:0032-3888    

DOI:10.1002/pen.760302110

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY

ISSN:0032-3888    

DOI:10.1002/pen.760302101

出版商:Society of Plastics Engineers    

年代:1990

数据来源: WILEY