Styrene-butadiene copolymer-bitumen

So far, in practice, there are various polymer-bitumen mixtures, such as PE-bitumen or elastomer-bitumen, including styrene-butadiene-styrene block copolymer (SBS)-bitumen or styrene-butadiene copolymer (SBR)-bitumen. The use of waterproof roofing membranes based on the thermoplastic elastomer-bitumen mixtures is increasing, especially in northern climate countries. 

The properties of bitumen paints (Section 2.14.2) can be favorably modified and adjusted to suit practical requirements by combination with other film-forming substances. For example, the thermoplasticity can be reduced and/or mechanical properties (e.g., hardness, extensibility) can be improved by adding polymers such as polyethylene, polypropylene, polyisobutene, and styrene-butadiene copolymers. The chemical resistance can also be improved high-quality corrosion protection coatings can be obtained by combination with alkyd resins. 

Nowadays commercial mixtures of bitumens with uncured synthetic elastomers are produced, e.g. ethylene-propylene-diene terpolymers (EPDM), styrene-butadiene sequence copolymers (SBS), and ethylene-acrylic ester-acrylic acid terpolymers (AECM). Mixtures with some thermoplastics are also commercial products, e.g. polyethylene (PE), ethylene-propylene copolymers (EPM), alpha-olefinic copolymers, atactic polypropylene (aPP), and ethylene-vinyl acetate copolymers (EVA). 

Polymer modified bitumen (Modbit) was developed in Italy around 1960 using atactic PP. The use of such composite systems in USA began during the mid 1970s. These systems based on PP or styrene-butadiene-styrene (S-B-S) block copolymer have used, as reinforcement non-woven fibreglass or PET... 

Styrene-butadiene-styrene (S-B-S) block copolymers are used in bitumen roofing formulations because of their suitable dynamic viscoelastic properties. 

Polymer-modified bituminous membranes were developed in Europe in the mid- 1960s and have been in use in North America since 1975. The polymeric systems have varied from natural rubber to more complex synthetic systems sueh as block copolymers and polymer blends. Most common polymers used as modifiers are polyisobutylenes, polybutadienes, polyisopienes, styrene-butiene-monomer, styrene-butadiene-rubber, butyl rubber, ethylene-vinylaeetate (EVA), atactic polypropylene (APP) as well as natural rubber. Polymers, such as atactic polypropylene or styrene-butadiene-styiene (SBS), impart flexibility and elasticity, improve cohesive strength, resist flow at high temperatures, and toughness.1 1 They are the most widely used modifiers of bitumen-based roofing materials. 

The butadiene-styrene block copolymers have now been available for over 15 years. Marketed by Shell (Cariflex TR), Phillips (Solprene T) and AN 1C (Europrene), these materials have established markets in the field of shoe soling, modification of polystyrene and polyolefins, as bitumen additives and in adhesive formulations. Whilst the shoe soling applications are, to some extent, subject to the whims of fashion, steady increase in use of these materials may be expected. Similar comments may be made concerning the thermoplastic polyurethanes which have also been available for a number of years. These materials combine the properties of strength, oil resistance and processibility. 

Chem. Desaip. /tqueous of dispersion of a styrene/1,3-butadiene/ac[ylic acid copolymer (50%), ammonia (< 5%), emulsifier Uses Binder for metal protective coatings, conosion protective coatings, seam-sealing compds., bitumen prods., flexible sealing coatings, min. substrates... 

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