Properties And Applications Of Elastomeric Polysulfides

The specialist properties of polysulfide polymers were immediately recognised on discovery, and technology was soon developed to convert these materials into useful products. In this Rapra Review Report, the author describes the factors controlling the structure of polysulfide polymers and the properties which influence their use and performance in products. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database provides useful references for further reading.

Revised Bestseller Offers Broad-Based Knowledge to a Wide Range of Technical Professionals The definitive guide to sealing operations in construction, this latest edition of Sealants in Construction focuses on the most current technology, methods, applications, and standards relevant to sealant performance. Providing guided direction on how to choose and apply sealants, determine the properties of those sealants, and test and establish the cause of sealant failures, it addresses the design and engineering of structurally glazed systems and the chemistry and properties of various generic types including silicones, hybrids, and urethanes. Divided into two parts, the book first covers basic topics relevant to the practical side of construction sealants, and is geared toward those interested in choosing the proper sealant. The second half introduces advanced topics that are more technical, includes historical context along with practical examples, and is directed toward anyone requiring more depth in these areas. An indispensable resource essential to your collection, this book: Explains the proper way to test sealants Evaluates standard test methods that are used with construction sealants Provides examples of emerging test methods appropriate for use with construction and highway sealants Outlines methods for calculating the required joint sizes in conventional sealing, glazing, and structural glazing Details the composition of the most popular types of sealants and hybrids Sealants in Construction covers the use of sealants in the construction industry and aims for the increased use of nondestructive test methods for all sealant applications and a more integrated quality management approach to sealing operations. This book is of interest to architects, contractors, engineers, sealant manufacturers, and students, and is relevant to a variety of technical disciplines.

This valuable book is devoted to problems of the synthesis, vulcanization, modification, and study of structure and properties of highly filled sealants based on polysulfide oligomers (PSO). The book summarizes information concerning chemistry, synthesis technology, structure, and properties of liquid thiokols and thiokol-containing polyesters. It also presents a literary survey on chemism and mechanisms for liquid thiokols vulcanization involving oxidants or through polyaddition. The book describes formulation principles of sealants, their properties, and application areas. The book provides research on vulcanization and modification of thiokol sealants involving thiokol-epoxy resin copolymers, unsaturated polyesters, and various isocyanate prepolymers. It describes studies of mechanisms underlying vulcanization of polysulphide oligomers by manganese dioxide, sodium dichromate and zinc oxide, and also of the structure and properties of sealants on the basis of a liquid thiokol and commercial “ТПМ-2” polymer depending on a chemical nature and the ratio of constituent oligomers. The book gives information on the influence of filling materials on vulcanization kinetics, rheological, and physico–mechanical properties of sealants depending on the nature of PSO. The book will be of interest to research personnel of scientific institutes and centers developing reactive oligomers and their compositions and studying their structure and properties as well as engineers working in science centers or enterprises working in the area of development, production, and application of polysulfide oligomers and sealants.

This first book in the Materials and Processes for Electronics Applications series answers questions vital to the successful design and manufacturing of electronic components, modules, and systems such as: - How can one protect electronic assemblies from prolonged high humidity, high temperatures, salt spray or other terrestrial and space environments? - What coating types can be used to protect microelectronics in military, space, automotive, or medical environments? - How can the chemistry of polymers be correlated to desirable physical and electrical properties? - How can a design engineer avoid subsequent potential failures due to corrosion, metal migration, electrical degradation, outgassing? - What are the best processes that manufacturing can use to mask, clean, prepare the surface, dispense the coating, and cure the coating? - What quality assurance and in-process tests can be used to assure reliability? - What government or industry specifications are available? - How can organic coatings be selected to meet OSHA, EPA, and other regulations? Besides a discussion of the traditional roles of coatings for moisture and environmental protection of printed circuit assemblies, this book covers dielectric coatings that provide electrical functions such as the low-dielectric-constant dielectrics used to fabricate multilayer interconnect substrates and high-frequency, high-speed circuits. Materials engineers and chemists will benefit greatly from a chapter on the chemistry and properties of the main types of polymer coatings including: Epoxies, Polyimides, Silicones, Polyurethanes, Parylene, Benzocyclobenzene and many others. For manufacturing personnel, there is an entire chapter of over a dozen processes for masking, cleaning, and surface preparation and a comprehensive review of over 20 processes for the application and curing of coatings including recent extrusion, meniscus, and curtain coating methods used in processing large panels. The pros and cons of each method are given to aid the engineer in selecting the optimum method for his/her application. As a bonus, from his own experience, the author discusses some caveats that will help reduce costs and avoid failures. Finally, the author discusses regulations of OSHA, EPA, and other government agencies which have resulted in formulation changes to meet VOC and toxicity requirements. Tables of numerous military, commercial, industry, and NASA specifications are given to help the engineer select the proper callout.

SCFs are currently the subjects of intense research and commercial interest. Applications such as the RESS (rapid expansion of supercritical fluid solutions) process are part of standard industrial practice. In view of their ever-growing importance in the polymer industry there is a need to fully comprehend how supercritical fluids interrelate with polymeric materials to realise the potential that can be gained from their use. The authors review the basic principles of SCFs and their application within the polymer industry: characteristics and properties, extraction of unwanted residual products, polymerisation solvents, and polymer impregnation. Processing applications such as plasticisation, foaming and blending are also considered. There is discussion of the potential within the polymer recycling industry for use of SCFs as cleaning agents or within supercritical oxidation processes. Around 400 references with abstracts from recent global literature accompany this review, sourced from the Polymer Library, to facilitate further reading. A subject index and a company index are included.

This report provides an excellent, clearly written report on the state-of-the-art of food contact elastomers. In the UK, the Ministry of Agriculture Fisheries and Food (MAFF), industry and Rapra have combined forces to study the issues surrounding rubbers in contact with food. A survey has been carried out of the food processing industry to determine which rubber products come into contact with food, contact area, duration of contact and temperature of contact. The results of this survey are found in the report and a compilation of data tables on each food industry studied is included as an appendix. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.