Caulking compositions

Liquid polymers with terminal mercapto groups (LP-2) are obtained when solid polyolefin poiysulfides are reduced. These liquid polymers may be oxidized to solid polymers in the presence of oxidizing agents, such as lead oxides. The liquid polymers are used in caulking compositions and as reactive flexibilizing agents in epoxy resins. 

The polyacrylate and ethylene-acrylic copolymers and one of the ethylene-propylene terpolymers (Nordel) were the best of the Intermediate temperature elastomers. Except for resistance to compression set, these materials were Inferior to the silicones in thermal stability as measured by their retention of tensile properties. The other EPDM compounds and butyl rubber were considerably inferior to the above-mentioned elastomers. It is not expected that the service life of the tested materials will be limited solely by their ability to resist hydrolytic degradation. The only caulking compositions which retained moderate physical integrity on thermal aging were the silicones. 

Hopefully, the information in this book will help hasten the adoption of plastic cements and assure the construction engineer of the merits of the widely used sealants and caulking compositions. 

Since the use of sealants and caulking compositions is essential for energy conservation in the construction of modern buildings, large quantities of hot melt and room temperature curing sealants and caulking compounds were used worldwide in... 

The original caulking compositions were bituminous or vegetable oil-based products but these have been supplemented by polybutene and butylrubber, natural and synthetic rubber, polyvinyl acetate, acrylic resin, polyurethanes, polysulfides and silicones. The last two are dlscused in detail in Chapters 11 and 12. 

Polybutenes have heen used for almost a century and while they are still used, most of this type sealant contains butyl rubber, which is a copolymer of butene and isoprene. Most building specifications, including Federal Specification, TT-S-001637, require solutions of butyl rubber instead of oil-based caulking compositions. Self curing butyl rubber sealants may contain phenolic resins,IS. resorcinol and hexamethylenetetramine. ... 

Emulsions of polyvinyl acetate and polyalkyl acrylates have been used as tub caulking compositions, spackling compounds and as building sealants.22 Acrylic sealants which harden in the presence of powdered iron or copper meet Federal Specifications TT-S-00230C. 27 Liquid monomers, such as polyethylene glycol dimethacrylate and butyl alpha—cyanoacrylate have been used as room temperature curing sealants.22 22. 

Modem construction techniques require the use of superior sealants and caulking compositions. Fortunately, the producers of these materials have provided a strong technical service backup for the civil engineer. Hence, these products are now accepted as standard materials of construction. 

While PC, latex emulsion concrete, and caulking compositions represent only a small percentage of the entire plastics business, they are one of the most important to the construction industry. The American construction industry has been dependent on plastic sealants and caulking compositions but has been slow to accept plastic concrete. Fortunately, the latter has been successfully used for many years in other countries and it is now being accepted in the U.S. 

Caulking compositions Isobutylene WATER-SOLUBLE Japan 110,262 POLYMERS 1979 Kasei CD U CL x ... 

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