Search Results for thermoplastic polyimides

Advanced thermoplastics are stiff, moldable plastics that compete with traditional engineering thermoplastics and thermosets owing to their good tensile, compressive, impact, and shear strength, electrical properties, and corrosion resistance. This article discusses commercial forms, family characteristics, properties and applications of the following advanced thermoplastics: homopolymer and copolymer acetals, fluoropolymers, ionomers, polyamides, polyamide-imides, polyarylates, polyketones, polyaryl sulfones, polybutylene terephthalates, polycarbonates, polyether-imides, polyether sulfones, polyethylene terephthalates, thermoplastic polyimides, liquid crystal polymers, polyphenylene ether blends, polyphenylene sulfides, and polysulfones.

This article discusses the properties and applications of two types of polyimide resins: condensation polyimides and addition-type polyimides. It describes the chemistry of condensation-type polyimides during synthesis, processing of polyamide acid precursor solution to polyimide, and preparation of polyimide films from thermoplastic polyamic acid precursors. The article reviews the chemistry of several addition-type polyimides, including phenylethynyl-containing imide oligomers, nadic end-capped polyimides, and LARC RP46. It explains the preparation processes of nadic end-capped amic acid oligomer resin solutions, including the preparation of resin powder and resin disks, adhesive film, adhesive bond specimens, and films.

The design and analysis of aerospace and industrial composite components and assemblies requires a detailed knowledge of materials properties, which, in turn, depend on the manufacturing, machining, and assembly methods used. This article, through several tables and graphs, provides the mechanical properties, physical properties, and service characteristics of representative composite fiber-resin combinations, including thermoplastic matrix composites such as thermoplastic polyester resins, thermoplastic polyamide resins, and thermoplastic polysulfone resins, and thermoset matrix composites such as thermoset polyester resins, thermoset phenolic resins, thermoset epoxy resins, thermoset polyimide resins, and thermoset bismaleimide resins.

This article is a compilation of abbreviations of terms, techniques, standards, compounds, and properties of materials that are relevant to the characterization and failure analysis of plastics.

This article discusses the thermal properties of engineering plastics and elastomers with respect to chemical composition, chain configuration, and base polymer conformation as determined by thermal analysis. It describes the processing of base polymers with or without additives and their response to chemical, physical, and mechanical stresses whether as an unfilled, shaped article or as a component of a composite structure. It summarizes the basic thermal properties of thermoplastics and thermosets, including thermal conductivity, temperature resistance, thermal expansion, specific heat, and glass transition temperature. It also provides information on polyimide and bismaleimide resin systems. Representative examples of different types of engineering thermoplastics are discussed primarily in terms of structure and thermal properties.

This article discusses the types, properties, and uses of continuous-fiber-reinforced composites, including glass, carbon, aramid, boron, continuous silicon carbide, and aluminum oxide fiber composites. While polyester and vinyl ester resins are the most used matrix materials for commercial applications, epoxy resins, bismaleimide resins, polyimide resins, and thermoplastic resins are used for aerospace applications. The article addresses design considerations as well as product forms and fabrication processes.

This article discusses the materials and properties of polymer-matrix composites to characterize each generic material according to its composition and method of manufacture. It contains a table that lists the key physical, mechanical, thermal, and electrical properties, and in-service conditions of concern for resin-matrix composites. Axes definitions, symbols, and special property calculations for composite material property tests are reviewed. The article provides an overview of the performance capabilities of selected polymer-matrix composite materials such as thermoplastic-matrix composites and thermoset-matrix composites. The thermoplastic-matrix composites include thermoplastic polyester resins and fiber resin composites; thermoplastic polyamide resins and fiber-resin composites; and thermoplastic polysulfone resins and fiber-resin composites.

This article describes the most significant tests to characterize the properties of constituent materials. It discusses the chemical, physical, and mechanical tests for determining the properties of reinforcement fibers and fabrics. The article provides information on some of the basic materials used for thermoset and thermoplastic resin matrices. It reviews the identification of the individual characteristics of thermoset and thermoplastic resin along with the test methods normally used for their determination. The article contains a table that lists properties and tests for uncured and cured thermoset-matrix resins and prepregs.

This article provides a summary of the concepts discussed in the articles under the Section “Constituent Materials” in ASM Handbook, Volume 21: Composites. The Section describes the major matrix resins and reinforcing fibers used in composite materials, as well as some of the intermediate material forms available for composite fabrication.

High-temperature-resistant polymers are used in aerospace, electronic, and other applications that demand outstanding elevated-temperature physical and mechanical properties. This article discusses the general characteristics of condensation-type polyimides and polymerization of monomer reactants (PMR) polyimides. It provides information on the applications of PMR-15 with illustrations.

This article illustrates typical fractographic features for a number of different composite materials. It describes the differences in fracture characteristics due to different loading, material processing, and environmental conditions. The article presents fractographic data obtained from epoxy matrix materials. Minimal fractographic data from other brittle thermoset resin systems are also presented. The article discusses the interlaminar fracture of composites with ductile thermoplastic matrices. It also provides information on the translaminar fracture features of the composite materials.

Molding compounds are plastic materials in varying stages of pellets or granulation that consist of resin, filler, pigments, reinforcement, plasticizers, and other ingredients ready for use in a molding operation. This article describes the material components and physical properties of sheet molding compounds (SMC). The three types of resin paste mixing techniques, such as batch, batch/continuous, and continuous, for an SMC operation are reviewed. The article discusses the design features and functional operations of the two types of SMC machines, namely, continuous-belt and beltless machines. It explains the formulation and processing of bulk molding compounds and reviews molding methods for bulk molding compounds, including compression, transfer, and injection molding. The effects of the fiber type and length and the matrix type on thermoset bulk molding compounds are discussed. It describes the four injection molding processes of injection molding compounds such as feeding, transporting, injecting, and flowing.

Polymers and polymer composites have become attractive for tribological applications due to their specific material properties. This article begins by discussing the fundamentals of polymer friction and wear. It summarizes the main polymer materials used in tribological applications. The article explains the effects of load, sliding velocity, and temperature on the friction coefficient. It describes three types of wear modes, namely, abrasive, adhesion, and fatigue. The article discusses the frictional behavior of polymer composites and polymer coatings. It concludes by providing information on tribotesting of polymers and polymer composites.

This article is a compilation of abbreviations, symbols, and tradenames for terms related to the properties, selection, processing, and applications of the most widely used nonmetallic engineering materials.

This introductory article describes the various aspects of chemical structure that are important to an understanding of polymer properties and thus their eventual effect on the end-use performance of engineering plastics. The polymers covered include hydrocarbon polymers, carbon-chain polymers, heterochain polymers, and polymers containing aromatic rings. The article also includes some general information on the classification and naming of polymers and plastics. The most important properties of polymers, namely, thermal, mechanical, chemical, electrical, and optical properties, and the most significant influences of structure on those properties are then discussed. A variety of engineering thermoplastics, including some that are regarded as high-performance thermoplastics, are covered in this article. In addition, a few examples of commodity thermoplastics and biodegradable thermoplastics are presented for comparison. Finally, the properties and applications of six common thermosets are briefly considered.

This article is a comprehensive collection of tables that list the values for hardness of plastics, rubber, elastomers, and metals. The tables also list the tensile yield strength and tensile modulus of metals and plastics at room temperature. A comparison of various engineering materials, on the basis of tensile strength, is also provided.

A thermosetting resin, or thermoset, is a synthetic organic polymer that cures to a solid, infusible mass by forming a three-dimensional network of covalent chemical bonds. Significant applications include construction and thermoset engineering plastics. This article discusses the general and family characteristics of thermosetting resin families, including allyls, aminos (urea formaldehyde and melamine formaldehyde), cyanates, epoxies, polybenzimidazoles, unsaturated polyesters, thermoset polyimides, phenolics, and vinyl esters. It also explains processing methods, including curing and curing agents. The article provides descriptions of commercial product forms and the wide array of applications of thermosetting resins. It also tabulates the performance properties (mechanical, thermal, electrical and chemical resistance) of some families of unfilled or unreinforced thermosetting resins and reinforced or filled grades.

Thermal analysis provides a powerful tool for researchers and engineers in determining both unknown and reproducible behavioral properties of polymer molecules. This article covers the thermal analysis and thermal properties of engineering plastics with respect to chemical composition, chain configuration, conformation of the base polymers, processing of the base polymers with or without additives; and the response to chemical, physical, and mechanical stresses of base polymers as unfilled, shaped articles or as components of composite structures. It also describes thermal analysis techniques, including differential scanning calorimetry, thermogravimetric analysis, thermomechanical analysis, and rheological analysis. This article also summarizes the basic thermal properties used in the application of engineering plastics, such as thermal conductivity, temperature resistance, thermal expansion, specific heat, and the determination of glass transition temperatures. It concludes with a discussion of the thermal and related properties of nine thermostat resin systems divided into three groups by low, medium, and high service temperature capabilities.