Acrylic plastics applications

The ophthalmic applications for plastics lenses include contact lenses which are now made of acrylic plastics. Another material for this application is a special hydrophillic acrylic polymer used in soft contact lenses. These lenses are much more comfortable than rigid contact lenses. 

The basic technique of using domes formed from acrylic sheet as skylights was developed in the 1950s and represented one of the earliest commercial applications of acrylic plastic. 

Volume 1 of this book is comprised of 25 chapters, and discusses the different types of natural rubber based blends and IPNs. The first seven chapters discuss the general aspects of natural rubber blends like their miscibility, manufacturing methods, production and morphology development. The next ten chapters describe exclusively the properties of natural rubber blends with different polymers like thermoplastic, acrylic plastic, block or graft copolymers, etc. Chapter 18 deals entirely with clay reinforcement in natural rubber blends. Chapters 19 to 23 explain the major techniques used for characterizing various natural rubber based blends. The final two chapters give a brief explanation of life cycle analysis and the application of natural rubber based blends and IPNs. 

Urethane acrylates were first utilized in floor tile coatings around 1972. As with polyesters, a large number of compositional variants can be synthesized. There is considerable captive production of these resins as well as a number of commercial offerings. This resin class finds particular utility in plastics applications. 

Complex reflectors within new vehicle headlamp assemblies typically must withstand temperatures of up to 400°F. Appropriate thermoplastic materials must be selected not only for the lamp backcan and lens, but also for the electronic/electrical connectors. Variations on filled polyester, poly(imides), bulk molding compound (a sheet molding compound [SMC] analogue), and nylon/poly(phenylene oxide) alloys are typically utilized in these applications. Poly(carbonate) (PC) or impact-modified PC is typically used in the lens applications where high heat is required. Acrylic plastics can and are most typically utilized in lens apphcations that do not require high heat, such as rear stop mount designs. 

For some applications, such as for repulpable type PSAs, it may be advantageous to incorporate high levels of acrylic acid because this makes the polymer more hydrophilic. At the same time, high levels of acid also improve the water-dispersibility of the adhesive, especially at higher pH where the acid groups are converted to the more water-soluble neutralized salt form. Since the high level of acid increases the of the resulting polymer, a non-tacky material results. To make the adhesive pressure sensitive, the polymer can be softened with water-dispersible or soluble plasticizers, such as polyethers [68]. 

Paints are complex formulations of polymeric binders with additives including anti-corrosion pigments, colors, plasticizers, ultraviolet absorbers, flame-retardant chemicals, etc. Almost all binders are organic materials such as resins based on epoxy, polyurethanes, alkyds, esters, chlorinated rubber and acrylics. The common inorganic binder is the silicate used in inorganic zinc silicate primer for steel. Specific formulations are available for application to aluminum and for galvanized steel substrates. 

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