This article focuses on characterization techniques used for analyzing the physical behavior and chemical composition of thermoset resins, namely chromatography and infrared spectroscopy. The main purpose is to give sufficient detail to permit the reader understand a particular test technique and its value to the thermoset resin field. Epoxy resins are emphasized in the examples because they dominate the airframe and aerospace industries. The article also provides information on two categories of characterization of the processing behavior of thermoset. The first studies the thermal properties of reactive thermoset systems, while the second utilizes these thermal characteristics as the basis for monitoring and control during processing.

This chapter describes the molecular structures and chemical reactions associated with the production of thermoset and thermoplastic components. It compares and contrasts the mechanical properties of engineering plastics with those of metals, and explains how fillers and reinforcements affect impact and tensile strength, shrinkage, thermal expansion, and thermal conductivity. It examines the relationship between tensile modulus and temperature, provides thermal property data for selected plastics, and discusses the effect of chemical exposure, operating temperature, and residual stress. The chapter also includes a section on the uses of thermoplastic and thermosetting resins and provides information on fabrication processes and fastening and joining methods.

This article covers the thermal analysis and thermal properties of engineering plastics with respect to chemical composition, chain configuration, and/or conformation of the base polymers. The thermal analysis techniques covered are differential scanning calorimetry, thermogravimetric analysis, thermomechanical analysis, and rheological analysis. The basic thermal properties covered include thermal conductivity, temperature resistance, thermal expansion, specific heat, and the determination of glass-transition temperatures. The article further describes various factors influencing the determination of service temperature of a material. Representative examples of different types of engineering thermoplastics are discussed in terms of structure and thermal properties. The article also discusses the thermal and related properties of thermoset resin systems.

This article describes the mechanisms of moisture-induced damage in polymeric materials, covering the characteristics of important structural plastics; the effects of moisture on glass transition temperature, modulus, creep, and stress relaxation of plastic materials; and moisture-induced fatigue failure in composites. The effect of moisture on the mechanical properties of thermoset resins and thermoplastics are also discussed.

This chapter provides a general description of materials and methods for manufacturing high-performance composites. The materials covered are polymer matrices and prepreg materials and the methods include infusion processes, composite-toughening methods, matrix-toughening methods, and dispersed-phase toughening. In addition, the chapter provides information on interlayer-toughened composites and honeycomb or foam structure composite materials. It also discusses the processes in optical microscopy of composite materials.

This chapter discusses the use of thermoset and thermoplastic resins in polymer matrix composites. It begins by explaining how the two classes of polymer differ and how it impacts their use as matrix materials. It then goes on to describe the characteristics of polyester, vinyl ester, epoxy, bismaleimide, cyanate ester, polyimide, and phenolic resins and various toughening methods. The chapter also covers thermoplastic matrix materials and product forms and provides an introduction to the physiochemical tests used to characterize resins and cured laminates.

The second-generation composite materials were added to increase the strain to failure of the primary phase and/or create a dispersed second phase, thereby enhancing the fracture toughness of the thermosetting matrix. These matrices offered novel design capabilities for composites in a variety of aircraft applications. To improve the damage tolerance of composite materials even further, an engineering approach to toughening was used to modify the highly stressed interlayer with either a tougher material or through the use of preformed particles, leading to the third generation of composite materials. This chapter discusses the development, processes, application, advantages, and disadvantages of dispersed-phase toughening of thermoset matrices. Information on the processes of particle interlayer toughening of composite materials is also included.

This appendix is a compilation of terms and definitions related to composite filament winding.

This article depicts typical fractographic features for a number of different composite materials, covering interlaminar and translaminar fracture characteristics in composite materials.

This chapter familiarizes readers with the many and varied thermoset composite fabrication processes and the types of applications for which they were developed. It describes wet lay-up, prepreg lay-up, and low-temperature vacuum bag curing prepreg processes, which are best suited for low-volume, medium-sized and larger parts. It also discusses filament winding and preforming processes (including weaving, knitting, stitching, and braiding) in addition to resin-transfer molding, resin film infusion, and pultrusion.

This chapter discusses design and certification considerations, including materials and process selection, the building block approach to certification, design allowables, and design guidelines. It also includes information on damage tolerance and environmental sensitivity.

Polymer-matrix composites are among the lightest structural materials in use today. They are also highly resistant to corrosion and fatigue and their load-carrying capabilities, such as strength and stiffness, can be tailored for specific applications. This chapter discusses the primary advantages and disadvantages of polymer-matrix composites, how they are produced, and how they perform in different applications. It describes the construction of laminates, the fibers and resins used, and the methods by which they are combined. It explains how strength, modulus, toughness, and high-temperature and corrosion behaviors are determined by the orientation, shape, and spacing of fibers, the number of plies, resin properties, and consolidation and forming methods. The chapter also covers secondary fabrication processes, such as thermoforming, machining, and joining, as well as production equipment and product forms, and include guidelines for optimizing tradeoffs when selecting fibers, resins, and production techniques.

This article describes key processing methods and related design, manufacturing, and application considerations for plastic parts and includes a discussion on materials and process selection methodology for plastics. The discussion covers the primary plastic processing methods and how each process influences part design and the properties of the plastic part. It also includes a brief description of functional requirements in process selection; an overview of various process effects and how they affect the functions and properties of the part; and the selection of processes for size, shape, and design detail factors.

This introductory article describes the various aspects of chemical structure and composition that are important to an understanding of polymer properties and their eventual effect on the end-use performance of engineering plastics, namely thermoplastics and thermosets. The most important properties of polymers and the most significant influences of structure on those properties are covered. The article also includes some general information on the classification and naming of polymers and plastics.

This article addresses some established protocols in characterizing thermoplastics, whether they are homogeneous resins, alloyed or blended compositions, or highly modified thermoplastic composites. It begins with a description of various approaches used for the determination of molecular weight (MW) by viscosity measurements. This is followed by a discussion of the use of cone and plate and parallel plate geometries in determining the viscoelastic properties of a polymer melt. Details on some of the chromatographic techniques that allow determination of MW and MW distribution of polymers are then provided. The article concludes with information on three distinctive, but complementary operations of thermoanalytical techniques, namely differential scanning calorimetry, thermogravimetric analysis, and thermomechanical testing.

The most common methods for preparing polymeric composites for microscopic analysis can be used for most fiber-reinforced composite materials. There are, however, a few composite materials that require special preparation techniques. This chapter discusses the processes involved in the preparation of titanium honeycomb composites, boron fiber composites, titanium/polymeric composite hybrids, and uncured prepreg materials.