About Polymer Concrete And Mortar

Polymer Concrete and Mortar Polymer concrete and mortar are binders, compounds, and aggregate mixtures that use epoxy, polyester, vinyl ester or other polymer resin bonds. They cure or set through chemical reactions, thermoset bonds, and multiple component binder systems. Polymer concrete and mortar provides much greater corrosion resistance than conventional construction materials such as Portland cement. Polymer concrete consists of polymer cement mixed with water, a coarse aggregate such as gravel or crushed stone, and a fine aggregate or sand. Polymer mortar is a mixture of a polymer binder or clinker and a fine aggregate. Both polymer concrete and polymer mortar are used to join components and form structures. Products such as grout are used to fill gaps between tiles and bricks. Thin set materials such as dry set mortar and dry bond mortar include polymer cement and are used in coating products. There are several chemical systems for polymer concrete and mortar. Acrylic binders provide excellent environmental resistance and fast setting times. Epoxy resins or binders exhibit high strength and low shrinkage during curing. They also provide toughness and resistance to chemical and environmental damage. Furan resins are formed from the polymerization or poly condensation of furfural, furfural alcohol, or other compounds containing a furan ring. They are commonly used in foundry binders, grinding wheels, refractories and other high-temperature applications. Polyurea resins or binders are used in place of phenolics or other formaldehyde resins in particle or fiberboard binder applications. Polyurethane provides excellent flexibility, impact resistance and durability. Other chemical systems for polymer concrete and mortar include silicone, polyester, and vinyl ester. Polymer concrete and mortar varies in terms of basic specifications and mechanical, electrical and thermal properties. Basic specifications include set/cure time, set/cure temperature, density, and shrinkage. Density is measured as the mass per unit area. Shrinkage is expressed as a maximum percentage. Mechanical properties for polymer concrete and mortar include compressive strength, bond strength, tensile strength, and modulus of rupture (MOR). Electrical properties include electrical resistivity, dielectric strength and relative permittivity. The dielectric constant is the relative permittivity of a material compared to a vacuum or free space. Thermal properties for polymer concrete and mortar include service temperature, thermal conductivity, and the coefficient of thermal expansion (CTE), the amount of linear expansion or shrinkage that occurs in a material with a change in temperature. There are a variety of features and applications for polymer concrete and mortar. Some products are abrasion resistant, castable, chemical resistant, conductive, fiber-reinforced, sprayable, or waterproof. Other products provide protection against wear, corrosion, or electrostatic discharge (ESD). Polymer concrete and mortar is often used in electrical power, high voltage (HV), construction, and structural applications. Some products are used as fillers and sealants.

Polyurethane: Polyurethane polymer is a combustible solid and will ignite if exposed to an open flame for a sufficient period of time. Decomposition products include carbon monoxide, oxides of nitrogen, and hydrogen cyanide. Firefighters should wear self-contained breathing apparatus in enclosed areas. Polyurethane polymer dust can cause irritation to the eyes and lungs. Proper hygiene controls and personal protective equipment (PPE), such as gloves, dust masks, respirators, mechanical ventilation, and protective clothing and eye wear should be used.

Amount of polyurethane used Application

Percentage of total (millions of pounds)

Building & Construction

1,459

26.8%

Transportation

1,298

23.8%

Furniture & Bedding

1,127

20.7%

Appliances

278

5.1%

Packaging

251

4.6%

Textiles, Fibers & Apparel 181

3.3%

Machinery & Foundry

178

3.3%

Electronics

75

1.4%

Footwear

39

0.7%

Other uses

558

10.2%

Total

5,444

100.0%

Polyurethane (PU), is any polymer consisting of a chain of organic units joined by urethane (carbamate) links. Polyurethane polymers are formed through step-growth polymerization by reacting a monomer containing at least two isocyanate functional groups with another monomer containing at least two hydroxyl (alcohol) groups in the presence of a catalyst. Polyurethane formulations cover an extremely wide range of stiffness, hardness, and densities. These materials include: 

Low-density flexible foam used in upholstery and bedding

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Low-density rigid foam used for thermal insulation.

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Soft solid elastomers used for gel pads and print rollers

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Hard solid plastics used as electronic instrument bezels and structural parts

Polyurethanes are widely used in high resiliency flexible foam seating, rigid foam insulation panels, microcellular foam seals and gaskets, durable elastomeric wheels and tires, automotive suspension bushings, electrical potting

compounds, high performance adhesives and sealants, Spandex fibers, seals, gaskets, carpet underlay, and hard plastic parts. Polyurethane products are often called "urethanes". They should not be confused with the specific substance urethane, also known as ethyl carbamate. Polyurethanes are not produced from ethyl carbamate, nor do they contain it.

Urethane: Urethane is not acutely toxic to humans, as shown by its use as a medicine. Acute toxicity studies show that the lowest fatal dose in rats, mice, and rabbits equals 1.2 grams/kg. or more. When urethane was used medicinally, about 50 percent of the patients exhibited nausea and vomiting, and long time use led to gastro enteric hemorrhages. The compound has almost no odor and a cooling, saline, bitter taste. Studies with rats, mice, and hamsters has shown that urethane will cause cancer when it is administered orally, injected, or applied to the skin, but no adequate studies of urethane-caused cancer in humans has been reported.