摘要:

AbstractThe physical properties of finished polymer blend composites are, in general, strongly influenced by the heterogeneity of the blend and the distribution of ingredients (especially reinforcement fillers) in each of the polymer phases. In this article, we review and update a processing technology specifically for the processing of multiphase rubber blend compounds in order to produce blend compounds with more desirable properties for practical applications. The basic concept is centered on the controlled‐ingredient‐distribution mixing (CIDM) process. The improvements in the following properties of rubber blend compounds are discussed: crack growth resistance, heat buildup, oil swelling, covulcanization, green strength, and permeabil

ISSN:0032-3888    

DOI:10.1002/pen.760251202

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractStudies on plastic alloys consisting of particles of brittle polymers dispersed in the matrices of ductile polymers were undertaken using the miniature polymer evaluation system (CSI Mini‐Max System). For the polycarbonate/poly(acrylonitrileco‐styrene) system, which had been found to show improved impact strength by Kurauchi,et al.using the conventional methods of molding and mechanical testing, it was verified that the miniature evaluation system gave the same results as those from the conventional methods. Ten other different combinations of ductile and brittle polymers were evaluated by using the miniature evaluation system. Among them the polycarbonate/poly(methyl methacrylate) system is found to be a toughened alloy. From these results, the requirements for the development of toughening in the ductile/brittle systems are discus

ISSN:0032-3888    

DOI:10.1002/pen.760251203

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractRheo‐optical and mechanical property studies with compression molded ultra‐high molecular weight polyethylene specimens at different temperatures indicate that their mechanical performance is dependent on the degree of fusion of the powder particles during compression and can be enhanced by heating the polymer powder at temperatures above 220°C. Although the mechanical performance of the compression molded specimens can be improved further by solid‐state drawing at a draw ratio 5, the anisotropic morphologies from molded specimen above 220°C have higher initial slope of stress to elongation, strength to break, and an outstanding elastic recovery in compreision to the compression molded specimens a

ISSN:0032-3888    

DOI:10.1002/pen.760251204

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe contributions of thecisandtransconfigurations of the main chain double bonds to the transition temperatures and rheological properties were determined for four well‐defined polymaleamides, which were prepared by the room temperature ring‐opening, step‐growth polymerization reactions of N,N′‐bisisomaleimide monomers with bifunctional primary diamines. The polymaleamides were glassy solids, which could be thermally isomerized into related polyfumaramides. The glass transition temperatures of the polyfumaramides, as determined by mechanical spectrometry, are systematically and markedly higher than those of the polymaleamides from which they wer

ISSN:0032-3888    

DOI:10.1002/pen.760251205

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractRecent investigations on interpenetrating polymer networks (IPNs) have included two component IPNs from polyurethanes and poly(methacrylates) and two component IPNs from polyurethanes and epoxies. All the IPNs were prepared by the simultaneous polymerization technique (SIN‐IPNs). Two types of IPNs, polyurethane‐poly(methyl methacrylate) (PU/PMMA) and polyurethane‐poly(methyl methacrylate‐methacrylic acid) (PU/PMMA‐MAA) were prepared. Improved phase miscibility and decreasing extent of phase separation was observed in both types of IPNs with increasing the NCO/OH ratio, decreasing molecular weight of the polyol in the PU and introduction of charge groups. A comparison was made between full‐IPNs, pseudo‐IPNs, graft copolymers and related homopolymers from polyurethanes and epoxies. Increased compatibility in full‐IPNs and graft copolymers was observed by means of DSC, SEM and was also further substantiated by a shift toward singleTgs as determined by dynamic mechanical spectroscopy. The introduction of opposite charge groups in two‐component IPNs from polyurethanes and epoxies led to improved compatibility (no phase separation) and enhanced mech

ISSN:0032-3888    

DOI:10.1002/pen.760251206

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractA slit die viscometer (SDV) was built and evaluated extensively. A major advantage of the SDV is the ability to measure in‐line rheological data in a continuous fashion, using a setup that most closely approximates the conditions encountered in a real extrusion process. Comparisons will be presented of viscosity data of the SDV to data from a capillary rheometer (CR) and a Rheometrics Mechanical Spectrometer (RMS). Viscosity values as measured on the SDV tend to be lower than those measured on the CR and RMS. Possible reasons for this disagreement will be discussed. The effect of temperature on viscosity, the effect of pressure on viscosity, and the effect of compressibility will be analyzed in detail. It will be shown that these effects can be substantial, particularly with certain types of polymers. Finally, the feasibility of using the slit die viscometer to determine first normal stress differences will be explore

ISSN:0032-3888    

DOI:10.1002/pen.760251207

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractA thorough study of an isothermal fluid motion within the mold cavity during the packing stage is presented. The fluid is considered Newtonian, and its compressible behavior is assumed to obey the Spencer‐Gilmore equation of state. Mathematical results indicate that the pressure built up during the packing stage is strongly dependent on the melt viscosity and the boundary of the cavity. The effects of pressure gradient and distribution, during this stage, on the shrinkage of the final products are also discusse

ISSN:0032-3888    

DOI:10.1002/pen.760251208

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThis paper reports the effect of humidity and temperature on the adhesive strength of a pressure sensitive adhesive (Flexbond 150) used to bond Mylar films. It has been found that, ill general, the adhesive strength decreases significantly with an increase in temperature. The effect of humidity on the bonding strength, however, was found to be process dependent. The sample preparation conditions, e.g., press weight for the bonding and the press time, are important in determining the humidity effect. The water sorption isotherm A 24°C for the adhesive was also determined. The amount of water sorbed by the adhesive at 95 percent relative pressure was found to be less than one weight percent

ISSN:0032-3888    

DOI:10.1002/pen.760251209

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractA kinetic model for the rheological behavior of polymeric systems, i.e. the Berkeley kinetic network model, is compared with a generalized transient‐network model. It turns out that the Berkeley kinetic network model fits quite well in the framework of the transient‐network model. From the point of view of the latter model, however, a number of parameters introduced in the kinetic‐network model are not independent constants as was supposed. Since the generalized transientnetwork model is totally based on microscopic assumptions, the parameters in this theory reveal information about the structure, whereas the physical interpretation of the parameters in the kinetic model is vague. Stress predictions of the generalized transient‐network model agree with experimental data from a 4 percent solution of polystyrene in arochlor, obtained from lit

ISSN:0032-3888    

DOI:10.1002/pen.760251210

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractA new mathematical model has been developed for the continuous esterification process of terephthalic acid (TPA) and ethlene glycol (EG) with consideration of oligomer characteristics. The liquid weight fraction in the reaction mixture, β, has been selected as a principal parameter in this model. The solubility of TPA in EG and bis β‐hydroxyethyl terephthalate (BHET) has been measured in order to estimate more precisely the concentration of each component. Good agreement has been obtained by plotting the log of solubility data of TPA in EG and BHET against the reciprocal of the absolute temperature with correlation coefficients of 0.998 and 0.989, respectively. The validity of these data has been verified in comparison with other d

ISSN:0032-3888    

DOI:10.1002/pen.760251211

出版商:Society of Plastics Engineers, Inc.    

年代:1985

数据来源: WILEY