ISSN:0032-3888    

DOI:10.1002/pen.760040102

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

ISSN:0032-3888    

DOI:10.1002/pen.760040103

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractThe melt‐filled portion of an extruder screw has been examined in a quantitative analytical fashion by numerous workers during recent years. The progress which has been made in defining flow patterns in this portion of the screw is reviewed, with special attention devoted to edge effects of the screw flights and the contribution of the circulatory cross‐channel component of flow. More recent work on the complex problem introduced by the existence of curvature in the screw channel is presented, along with consideration of distortion of the streamlines caused by non‐isothermal conditions and non‐Newtonian fluid properties of the molten

ISSN:0032-3888    

DOI:10.1002/pen.760040104

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractThe effect of a bimodal molecular weight distribution on the flow properties and stress crack resistance of polyethylene is investigated. It is found that the melt viscosity of a bimodal polyethylene is less shear dependent at high shear rates than a log normal distribution of equivalent weight average molecular weight and ratio of weight average to number average molecular weight. Spiral mold studies indicate that the bimodal polymer flows more readily under injection molding conditions. The stress crack resistance of the bimodal polymer is shown to be superior to other polyethylenes of the same weight average molecular weight.

ISSN:0032-3888    

DOI:10.1002/pen.760040105

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractBicyclo [2.2.1] hepta‐2,5‐diene, the reaction product of acetylene and cyclopentadiene, and vinyl chloride readily copolymerized by a novel mechanism, to form copolymers containing the nortricyclene group whose softening points rapidly increase with increasing nortricycl one concentration. For each weight per cent copolymerized bicycloheptadiene, the softening point of the vinyl resin is increased about 1°C, making it the most effective comonomer known for this purpose. At the same time increasing nortricyclene concentration disrupts polymer crystallinity, lowers the resin's melting point, and hence its processing temperature, by about 3°C for each weight per cent copolyme

ISSN:0032-3888    

DOI:10.1002/pen.760040106

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractThe impact strength of a thermoplastic is shown to be a strong function of several variables. Among these are type of molding, molding conditions, molecular orientation, test temperature, and notches. Particularly significant is a maximum in the response of impact strength to molding temperature. The tensile impact test was used as a tool for these determinations.

ISSN:0032-3888    

DOI:10.1002/pen.760040107

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractThere are several pieces of evidence in the published literature for the existence of a hexagonal crystalline form of polypropylene. Evidence obtained by infrared absorption, x‐ray diffraction, differential thermal analysis, and annealing experiments is consistent with the view that the quenched state of polypropylene is a truly crystalline one (presumably of hexagonal type) with a very small crystallite siz

ISSN:0032-3888    

DOI:10.1002/pen.760040108

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractDielectric measurements made at 60 cycles per second over a temperature range of −40 to 200°C on small (0.2 g) samples arc most useful in studying acrylic polymers. Not only has this method elucidated structure, but the study of some structures has led to new interpretations emphasizing the value of this type of measurement. Data on a number of acrylic polymers are shown. Several copolymer systems are discussed. It is suggested that 60 c/s measurement of stereospecific PMMA samples can show more about molecular arrangements than has previously been reveal

ISSN:0032-3888    

DOI:10.1002/pen.760040109

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractAn investigation of the effect of sample dimensions on the oxidation of polypropylene is described. The results are used to select testing conditions. Two examples of the utility of the method are presented. First, a control method for uninhibited polypropylene and, secondly, an investigation of the synergistic effect between 2,6‐di‐t‐butyl‐p‐cresol and dilaurylthiodip

ISSN:0032-3888    

DOI:10.1002/pen.760040110

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractChemical structures limited to phosphines and their derivatives, including phosphine oxides, phosphonium salts and halogen‐phosphorus compounds useful for fireproofing are discussed. In addition to these P‐C bond containing compounds, structures containing P‐O‐C bonds are mentioned only if they are directly formed from halophosphorus substances. The general approaches to fireproofing are described. They include physical changes, unreactive additives, reactive comonomers, substitution of other functional groups and addition to a preformed polymer. Much of the literature is reviewed and the commercial importance of certain methods for both cloth and plastics are in

ISSN:0032-3888    

DOI:10.1002/pen.760040111

出版商:Society of Plastics Engineers, Inc.    

年代:1964

数据来源: WILEY