ISSN:0032-3888    

DOI:10.1002/pen.760060202

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractThe application of silane coupling action produces significant improvements in physical properties in various thermpolastic resin systems. Both glass‐reinforced thermoplastics and the more conventional filled thermoplastic resin systems were studied. An order of specificity between resin and coupling agent exists for thermoplastic resins similar to that of thermosets. The interaction with thermosets is considered copolymerization, wereas that with thermoplastics is not yet clearly defined. The silanes are incorporated by pre‐treatment (best for glass reinforcement) or by addition during normal compounding. Fillers are added for a specific result, often with sacrifice of physical strength. Data presented show that silane addition upgrades filled thermoplastics to the level of clear resins and sometimes above. The effect of silanes on electrical properties of filled thermoplastics are also repor

ISSN:0032-3888    

DOI:10.1002/pen.760060203

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractAn Instron tensile tester has been modified to measure the thermal expansion of polymer films. The method greatly simplifies the experimental procedure necessary for the standard ASTM dilatometric thermal expansion measurement, particularly for thin films. Thermal expansion measurements were made for films of polyester, polycarbonates, vinyls, cellulosies, and polyolefins from room temperature up to 300°F. Second‐order transition temperatures were determined by plotting thermal elongation vs temperature; the transition temperature is indicated by a change in slope. Both expansion coeffcients and transition temperatures as determined by this method give excellent agreement with values reported in the literatu

ISSN:0032-3888    

DOI:10.1002/pen.760060204

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractThere is considerable literature on the behavior of polyethylene below 200°C and above 400°C. This paper presents results on both high and low density polyethylene between 2000and 400°C, a range of practical import for various fabrication and processing steps. Practical exposure times may be short and the experimental procedures were designed to give meaningful results for times as low as 1 min. The principal effects are chain‐session and oxidation. Session was isolated by applying an atmosphere of pure nitrogen and proved uite shlow at 300°C but rapid at 400°C. The course of scission and produces discoloration, odor, and rising carbonyl content. A brief discussion is given of the role of diffusion in oxi

ISSN:0032-3888    

DOI:10.1002/pen.760060205

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractColor development in outdoor applications has been widely used as an indication of breakdown in plastic materials although this does not always indicate a change in physical properties. Appearance factors are easily and precisely evaluated by measuring color and surface changes. Measurement of physical property changes is more comples and more meaningful. An optimum test method should measure a property with time, environment and sample form. Ideally, the data should determine service life. The test specimen should be adaptable to a variety of samples. Of the many physical tests of weatherability, impact strength appears most interesting. An inexpensive Variable Impact Tester was Modified and Developed for Measuring the effect of aging on rigid PVC. Data are presented showing the relation between impact values and temperature, sample thickness, process conditions and various environmental exposures.

ISSN:0032-3888    

DOI:10.1002/pen.760060206

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractAn optical method has been developed to provide quantitative results useful for characterizing the crazing of transparent plastics. The procedure consists of the detection of discontinuities in a beam of light that scans the specimen in a direction perpendicular to the line of crazing. The light is transmitted to a photomultiplier that is connected with an amplifying system and a recorder that provides a diagram of the light energy modulated by the lines of crazing. The specimen is scanner both before and after subjecting it to a treatment that causes crazing, and the crazing index is considered to be the difference between the area below the two curves.

ISSN:0032-3888    

DOI:10.1002/pen.760060207

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractThe pressure‐volume‐temperature behavior for both solid and molten polypropylene was determined for pressures up to 618 atmospheres. These data were measured with a newly developed compressibility device capable of obtaining precise and accurate data. Compressibilities calculated from the experimental data compared favorably to the limited existing literature data. Constants were determined for the Spencer‐Gilmore polymer equation of state for both the solid and molten mat

ISSN:0032-3888    

DOI:10.1002/pen.760060208

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractThe static coefficients of friction of solid polyolefins against metal surfaces has been determined as functions of pressure, temperature, and metal surface finish. The polymers studied were a low debsity (branched) polyethylene, a high density copolymer, and a high density (linear) polyethylene homocopolymer, and a high density (linear) polyethylene homopolymer. Four metal surfaces were used, with surface roughnesses ranging from 1 1/2 to 18 microinches. The pressure and temperature ranges were 0 to 355 psig and 72 to 225°F, respectively. Data were obtained for the polymers in two forms: granules and flat smooth dise, except for the high density homopolymer which was tested in the disc from only. In general, the results indicated that, for all granules, the coefficient was essentially independent of pressure, but decreased with increasing temperature until the melting point was reached; it varied with metal surface roughness which was greatest for the low density polymer. For the smooth surfaced disc samples, the coefficient also decreased with increasing pressure with high values at low pressure indicating strong adhesion between the polymer and metal surfaces

ISSN:0032-3888    

DOI:10.1002/pen.760060209

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractInternal pressure measurments have been made on two common plasticizers, di‐isoöctylphalate and dioctylsebacate, as a function of temperature. The ratios of internal pressure to cohesive energy density (as calculated by the method of Small) were 1.22 for dioctylsebacate and 1.17 for di‐isoöctylphthalate. As in the case of simpler molecules the product of internal pressure and the square of the specific volume was constant for each plasticizer over the temperature renge studied. This implies that even in the absence of any other effects both an upper and lower critical solution temperature would be expected in mixed systems if the coefficients of thermal expansion of the components of the mixed system are sufficiently diff

ISSN:0032-3888    

DOI:10.1002/pen.760060210

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY

摘要:

AbstractTensile stress rupture is an important engineering property of plastics required in desiging parts subject to continuous or intermittent stress over long periods of time, especially in corrosive environments. This paper presents tensile stress rupture results on polypropylene and some of their applications in a program conducted over the past several years. Among the structural and compositonal paramaters studied in this work are the effects of molecular weight, molecular weight distribution, isotactic content, polyblends, and fillers on the shape and slope of the stress rupture‐time curve. Data are presented showing the interrelationships between these variables, and the agreement with current stress rupture theories is discusse

ISSN:0032-3888    

DOI:10.1002/pen.760060211

出版商:Society of Plastics Engineers, Inc.    

年代:1966

数据来源: WILEY