Polymer Modifiers
Synthetic polymers are produced in different types of reactions. Many simple hydrocarbons, such as ethylene and propylene, can be transformed into polymers by adding one monomer after another to the growing chain. Polyethylene, composed of repeating ethylene monomers, is an addition polymer. It may have as many as 10,000 monomers joined in long coiled chains. Polyethylene is crystalline, translucent, and thermoplastic—i.e., it softens when heated. It is used for coatings, packaging, molded parts, and the manufacture of bottles and containers. Polypropylene is also crystalline and thermoplastic but is harder than polyethylene. Its molecules may consist of from 50,000 to 200,000 monomers. This compound is used in the textile industry and to make molded objects.
Other addition polymers include polybutadiene, polyisoprene, and polychloroprene, which are all important in the manufacture of synthetic rubbers. Some polymers, such as polystyrene, are glassy and transparent at room temperature, as well as being thermoplastic. Polystyrene can be coloured any shade and is used in the manufacture of toys and other plastic objects.
Polymer Modified Bitumen
Pavements designed and constructed for heavy duty traffic and extreme weather conditions require specially designed and engineered bitumen grades. By enhancing the characteristics of normal bitumen with the addition of a polymer we succeed to obtain modified bitumen that allows the mixture to be more cohesive, with much more strength and significant higher resistance to parameters like fatigue and permanent deformations for road pavements.
PMBs have been successfully used for several decades in the road industry.
PMB’s Qualities
Greater rigidity
Better resistance to permanent deformation
Higher resistance to crack propagation
Better water resistance
Much higher durability
Styrene-Butadiene-Styrene (SBS) describes a family of synthetic rubber derived from styrene and butadiene. SBS is a thermo plastic elastomer that has an excellent abrasion resistance and aging stability when blended with bitumen, making it the perfect bitumen modifier to achieve cold flexibility and elastic properties. This material has the ability to retain its shape after being stretched and therefore, is widely used in modified bitumen roofing, coatings, sealants and paving amongst other applications.