ISSN:0272-8397    

DOI:10.1002/pc.750030402

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0272-8397    

DOI:10.1002/pc.750030403

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe mechanical properties of short, fiber‐reinforced polymers are governed as much by the interface as by the properties of fiber or polymer. Interface properties of importance include adhesion and radial and longitudinal (frictional) stresses. These directly govern strength, modulus, and toughness of the composite and indirectly affect the resistance of the composite to environmental influences, such as water. These interface properties and the resulting interactions under applied stresses are examined and their influence on mechanical properties is discusse

ISSN:0272-8397    

DOI:10.1002/pc.750030404

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractPreliminary results are presented that demonstrate that the chemical and physical structure of the polypropylene at the mica‐polypropylene interface can be markedly different from that of the bulk polymer. This results from the ability of the mica to nucleate the crystallization of polypropylene, from the adsorption of polar impurities onto the mica surface, and from the effect of the mica surface on degradation reactions, particularly with chlorinated hydrocarbon coupling agent

ISSN:0272-8397    

DOI:10.1002/pc.750030405

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractThermoplastics and thermoset materials filled with inexpensive, mainly inorganic, particulates are an important class of engineering plastics. Here, the short fiber and flake fillers play a major role. In this paper, the melt rheology and processability of these resins is reviewed, and the flow behavior of mica‐filled polyethylene is discussed in greater detail

ISSN:0272-8397    

DOI:10.1002/pc.750030406

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractAs in the case of fibers, the mechanical properties of plastic composites containing mica flakes are extremely sensitive to flake orientation in the direction of an applied stress, so that even a small angular displacement can cause major reductions in the strength, modulus, and fracture toughness. In order to encourage parallel alignment of mica flakes in a thermoplastic composite, two methods of flow orientation were examined. In the first series, rectangular billets of mica‐filled, high‐density polyethylene were hot‐pressed in order to cause longitudinal melt flow in a narrow channel. A parallel series of experiments was also carried out with mica‐filled polypropylene in which the composite was extruded and calendered into a thin, continuous strip. In both processing techniques, the resulting extensional flow produced large increases in the tensile and flexural properties. The performance of the mica‐filled poly‐propylene was limited by its tendency to fibrillate during rolling. Drop‐impact measurements recorded a four‐fold increase in fracture toughness. The increased tensile and flexural properties were attributed to both the greater degree of parallel alignment of the mica flakes and the increased molecular orientation in the direction of flow. Such flow orientation methods appear necessary if the full benefit of mica‐flake reinforcement

ISSN:0272-8397    

DOI:10.1002/pc.750030407

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractUpgrading mica by increasing aspect ratio and coupling efficiency and combining mica with fibers has led to new uses as a reinforcement for thermoplastics and thermosets. The greatest growth in mica use has been in the thermoplastics, such as polypropylene and thermoplastic polyesters. Effects to be expected from using mica as a reinforcement include improved tensile and flexural strength, much‐increased dimensional stability and heat resistance, enhanced stiffness and electrical resistivity, and reduced permeability to gasses and liquids. Major parameters that influence the composite properties include the mica flake size, orientation, aspect ratio and volume fraction, coupling efficiency, and crystallinity of the polymer matrix. Mica composites are molded from direct blends or are precompounded in the manner used for fillers. Mica‐reinforced polypropylene (PP) is cost‐effective in replacing glass‐fiber‐reinforced PP and may even substitute for glass‐reinforced Nylon 66 in some applications. Markets for fillers for plastics are expected to grow faster than for the base polymers due to low cost, availability, and low energy utilization. Mica is expected to be one of the fillers with the highest market

ISSN:0272-8397    

DOI:10.1002/pc.750030408

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe influence of muscovite mica on the tensile, flexural, and mold shrinkage properties of composites with polypropylene (PP) were investigated. The best results in tensile and flexural properties at room temperature were observed for the physicochemical‐treated mica followed by silane‐treated mica. The mechanical properties could be correlated with the PP‐mica interactions, as observed in the scanning electron microscope (SEM). In the present study, with mica aspect ratio equal to about 30, the optimum performance was obtained for the average flake diameter 80 ⩽ d (μm) ⩽ 280. Finally, the results of coloration and weathering are discussed. It was found that the PP/30 percent mica formulation has superior weathering characteristics over the nea

ISSN:0272-8397    

DOI:10.1002/pc.750030409

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractShort glass fibers for reinforcements of plastics have been commercially produced for over three decades. During this period, they have been used in virtually every polymer, as well as in other matrices, such as concrete and plaster. Their tensile strength/cost performance is still three times that of Kevlar® and more than 30 times better than carbon fibers. Similarly, excellent modulus/cost performance and high temperature/cost performance can be achieved. This article gives a review of short‐fiber composites: their properties and use. Included is a comparison of compoundingvs.in‐house blending, fiber/flake hybrids, and reinforced polymer blends. Finally, several new materials still in development stages will be exam

ISSN:0272-8397    

DOI:10.1002/pc.750030410

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY

ISSN:0272-8397    

DOI:10.1002/pc.750030411

出版商:Society of Plastics Engineers, Inc.    

年代:1982

数据来源: WILEY