摘要:

AbstractRecent progress in the studies of molecular and microstructure of interfaces and interphases in composites, coatings, and adhesive joints is reviewed. Remarkable progress has been made in elucidating the structure of silane coupling agents and their function with respect to dry and wet strengths of multiphase systems. Aminosilanes attracted major effort in the past. It is now understood that the structure of partially cured hydrolyzate is complicated. When adsorbed from a natural pH solution and dried in air at room temperature, approximately half of the amine groups form amine bicarbonate salt with the CO2in air. The rest of the amine groups are either intra‐ and intermolecularly hydrogen bonded to neighboring silanol groups or free from hydrogen bonding. There exists chemical bonding at the glass/silane or metal/silane interfaces. The surface characteristics, including acidity, topology and homogeneity, influence the structure of the coupling agent. The coupling agent interphase shows a gradient in various properties. Silanes tend to be ordered in the interphase and the degree of organization depends largely on the organofunctionality. The orientation and organization of the silane affects the reinforcement mechanism. There are chemisorbed and physisorbed silanes in the interphase. The coupling agent/matrix interface is a diffuse boundary where intermixing takes place due to penetration of the matrix resin into the chemisorbed silane layers and the migration of the physisorbed silane molecules into the matrix phase. With proper selection of the organofunctionality and the curing conditions, silanes can chemically react with the matrix to form copolymers. The existence of the matrix interphase is now well accepted and the effect of the interphase on the mechanical properties has been studied. It has been recognized that modification of the matrix interphase, such as a coating applied on the fiber using a similar resin as the matrix, has a complex effect on the mechanical performance. It is noteworthy that attempts to synthesize new coupling agents and to utilize the existing coupling agents more effectively still continue. Based on the molecular understanding, new concepts in the reinforcement mechanism have appeared which recognize the importance of interpenetrating networks, the structure of silane in the treating solution, and the microheterogeneity of the glass surfaces. The knowledge obtained through the studies of composites can be applied to organic coatings and adhesive joints provided that the geometrical factors are taken into consideratio

ISSN:0272-8397    

DOI:10.1002/pc.750050202

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractDynamic mechanical experiments were performed on an amine‐cured high performance epoxy system containing two types of epoxies and one amine. The system approximates a commercial resin system used widely as matrix material for graphite composites and whose main ingredients and composition are 88.5 percent of tetraglycidyl 4,4′‐diamino diphenyl methane (TGDDM) and 11.5 percent of polyglycidyl ether of Bisphenol A Novalac epoxy with varying compositions of 4,4′‐diaminodiphenyl sulfone (DDS), ranging from 19 to 40 PHR. Specifically, the effects of DDS and Novalac content as well as processing conditions including the particle size of solid components, the mixing speed, mixing temperature, and the mixing duration of the components on the dynamic mechanical properties of the epoxy polymer were investigated. A viscoelastic transition in the dynamic spectrum which was observed to be quite sensitive to the sample'sTgin conjunction with incomplete crosslinking reactions allowed for interrelating the composition and processing variables to the structure and bulk properties of this epo

ISSN:0272-8397    

DOI:10.1002/pc.750050203

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractLarge diameter pipes and structures are manufactured with jute reinforced polyester resin. A modified filament winding machine is used to take the jute cloth on the rotating mold acting as a collapsible mandrel. The effect of calendering, fillers and poly(vinyl acetate) on jute reinforcing cloth and the results on the ultimate mechanical properties of the composite are studied. The effect of load during the curing of polyester and its effect on the strength of structure is reported. These findings are used in manufacturing of large diameter structures with improved mechanical properties.

ISSN:0272-8397    

DOI:10.1002/pc.750050204

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe effect of processing variables on the flammability and mechanical properties of state‐of‐the‐art and advanced resin matrices for graphite composites were studied. Resin matrices which were evaluated included state‐of‐the‐art epoxy, phenolic‐novolac, phenolic‐Xylok, two types of bismaleimides, benzyl, polyethersulfone, and polyphenylsulfone. Comparable flammability and thermochemical data on graphite‐reinforced laminates prepared with these resin matrices are presented, and the relationship of some of these properties to the anaerobic char yield of the re

ISSN:0272-8397    

DOI:10.1002/pc.750050205

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThis study examined the stress relaxation properties of six urethane reaction injection molded (RIM) systems, both reinforced and non‐reinforced RIM systems from room temperature to 100°C. Data is presented which shows the dynamic mechanical (DMS), differential scanning calorimetry (DSC), physical properties, and stress relaxation data. The major conclusion from this work is that the state of hard segment (amorphous or crystalline) makes a vast difference in the polymer's reaction to stre

ISSN:0272-8397    

DOI:10.1002/pc.750050206

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe compressive creep behavior of rigid unreinforced and particulate reinforced polyurethane foams at different densities, filler contents, temperatures, and loads was investigated. The creep behavior could be described by a power function of time and its temperature dependence by an Arrhenius type relation. The addition of particulate rigid fillers enhances the creep resistance as well as the foam elastic modulus. Particulate reinforcement of polyurethane foams was found to be efficient for the higher foam densities, especially for higher filler levels.

ISSN:0272-8397    

DOI:10.1002/pc.750050207

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThree‐phase syntactic foams consisting of a close‐packed microballoons bed, binding resin, and air voids are reported. Preparation methods varied from simple dry‐blending with a solid powdery resin‐to‐resin coating of spheres from polymer solutions. By holding the hollow spheres volume fraction constant and at the maximum packing, a property studied was a function of a single variable, namely, resin volume fraction, void content or density. Mechanical properties are reported as function of one of these variables. The temperature effect was investigated on polyimide based foams. The dielectric constant is shown to obey a logarithmic rule of mixtures. Modified modulus‐composition equations are shown to be applicable for prediction of moduli values of the three‐

ISSN:0272-8397    

DOI:10.1002/pc.750050208

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

ISSN:0272-8397    

DOI:10.1002/pc.750050201

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY