As an engineering building material, polymers have become increasingly essential. The applications and properties of polymers are broad due to the ease of fabrication and the ability to produce finished polymers at a low cost. Common examples of polymers include rubbers, plastics, thermoplastic elastomers, adhesives, sealants, paints, and foams.
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Polymers can be defined as a long chain of molecules that are continuously repeated. Polymer materials have been widely used in the construction industry due to their superior chemical and physical properties, and have been utilized in wall insulation, wire and cable, drainage pipe, and insulation layers of water supply pipes.
Frequently utilized polymers include organic silicon resin (OSR), Phenolic resin (PF), polypropylene (PP), polystyrene (PS), polyester resin (PR), polymethylmethacrylate (PMMA), polyvinyl chloride (PVC), and polyethylene (PE).
Types of Polymers And How They Are Utilized In Construction
Epoxy resin is a very common and popular type of polymer with a broad range of construction applications. Epoxy resins are well known for their durability and high performance. They are fundamental blocks for reinforced plastics, coatings, adhesives, and composite materials such as carbon fiber and fiberglass, which when exposed to harsh conditions remain intact.
Epoxy resins offer numerous desirable chemical and physical properties when properly cured, such as heat resistance, corrosion resistance, high electrical insulation, high compression tensile and bending strengths, adhesion to a variety of substrates, and resistance to chemicals, particularly in alkaline environments.
Epoxy resins bond to stone, glass, metal, concrete, most plastics, and wood, resulting in an incredibly versatile and adaptable construction material. In construction, epoxy is generally utilized in roofs, flooring, walls, and laminated wood. In painting and coating, it is generally used in heavy-duty protective coatings, outdoor coatings, sealers, and primers.
Ethyl Vinyl Acetate
Ethyl Vinyl Acetate, which is commonly known as EVA, is a copolymer of vinyl acetate and ethylene. EVA is a thermoplastic that is both elastic and tough and has excellent clarity and gloss. EVA has numerous important properties such as excellent adhesion to many nonporous and polar substrates. Additionally, the product is low cost, has good flex-crack and puncture resistance, as well as good heat-sealing and hot-tack.
EVA has a wide range of uses in construction such as encapsulation of solar panels. Various plastic sheets, metal surfaces, and coated papers all use EVA emulsions as adhesives. Furthermore, hot-melt adhesives, hot glue sticks, and top-notch soccer cleats are all made with EVA, wax, and resin additives.
One of the most extensively used and produced plastics on the planet is polyethylene (PE) with 10 million tons produced worldwide yearly.
PE is an important family member of polyolefin resins. PE is a versatile synthetic resin made from the polymerization of ethylene. It is a durable and lightweight thermoplastic with a variable crystalline structure. PE is classified as a thermoplastic, meaning this material can be heated, cooled, and reheated again without it significantly degrading. This ability makes it able to be molded and recycled easily in contrast to thermoset plastics, which can only be heated once.
Ultra-high Molecular Weight Polypropylene (UHMW), Low-Density Polyethylene(LDPE), Linear Low-Density Polyethylene (LLDPE), High-Density Polyethylene (HDPE) are the most common polythene major compounds.
In construction, polymers have numerous uses such as vapor retarders, flooring, window films and countertop protection, and even roofing. Polyethylene sheets can be used to block off rooms, cover building components, in foam underlay, in damp-proof membranes, for coatings, and to protect people from lead poisoning.
Polycarbonate is one of the fastest-growing construction engineering plastics, with the global demand for polycarbonate exceeding 1.5 million tons. Polycarbonates are transparent, tough, hard, stiff, and strong thermoplastics. They can withstand and maintain rigidity at temperatures up to 140°C and toughness at -20°C, with special grades going even lower.
The material exudes high dimensional stability and excellent mechanical properties. Additionally, the material is thermally resistant up to 135°C and is classified as a slow burner material.
However, some disadvantages are that there is limited chemical and scratch resistance, as well as its tendency to turn yellow when exposed to UV light for a long period. These drawbacks and constraints can be overcome by the addition of various additives to the material during the manufacturing process through co-extrusion.
Polycarbonate is a high-performance thermoplastic commonly utilized in building and construction items, ranging from skylights and windows, to roof domes and wall panels, to LED lighting exterior elements. Polycarbonate is tough and compact, with great optical clarity, high impact, and heat resistance, as well as excellent flammability resistance, making it ideal for these applications.
The Future of Polymers
The second-largest sector to utilize the wide range of applications of polymers is the building and construction sector. These applications range from structural to non-structural uses.
Material selection for engineering applications is usually based on the material’s ability to withstand environmental conditions and mechanical stress, even though they inevitably are expected to fail. Therefore, there is interest in developing a polymer product that has self-healing properties further inspired by our natural environment. The product is likely to be utilized for coatings, electronics, and transport. However, the main issue for the development of this product is large-volume applications.
In addition to self-healing polymers, a smart or reactive polymer could be developed with the ability to change in response to surroundings. For example, in response to the change in outside temperature, chemical agent, or light.
Potentially, polymers could also be incorporated as functional additives for traditional building materials such as mortar and concrete. In construction engineering, these polymer-based building materials have enormous potential.
References and Further Reading
Cuddihy, E.F., Coulbert, C.D., Liang, R.H., Gupta, A., Willis, P. and Baum, B., 1983. Applications of ethylene-vinyl, acetate as an encapsulation material for terrestrial photovoltaic modules (No. NAS 1.26: 172862) https://ntrs.nasa.gov/citations/19830021538
Sandberg. n.d. Polymers in Construction. [online] Available at: <https://www.sandberg.co.uk/consultancy/polymers/polymers-in-construction/#:~:text=Polymer%20materials%2
Corporation, R., n.d. Epoxy Can System For Repair Works. [online] Good Use Hardware Co., Ltd. Available at: <https://www.gooduse.com.tw/en/category/CA_can_system_mortar.html
Hinsley, N., 2012. Polyethylene Film- Polyethylene Sheeting- What is it,?. [online] www.globalplasticsheeting.com. Available at: <https://www.globalplasticsheeting.com/our-blog-resource-library/bid/76215/polyethylene-sheeting-what-is-
Badiee, A., Ashcroft, I.A. and Wildman, R.D., 2016. The thermo-mechanical degradation of ethylene-vinyl acetate used as a solar panel adhesive and encapsulant. International Journal of Adhesion and Adhesives, 68, pp.212-218. https://www.sciencedirect.com/science/article/pii/S0143749616300549
Arrighi, V., 2015. 5 synthetic materials that will shape the future. [online] World Economic Forum. Available at: <https://www.weforum.org/agenda/2015/02/5-synthetic-materials-that-will-shape-the-future/>
Akovalı, G. ed., 2005. Polymers in construction. iSmithers Rapra Publishing
British Plastics Federation. n.d. Polycarbonate (PC). [online] Available at: <https://www.bpf.co.uk/plastipedia/polymers/Polycarbonate.aspx#:~:text
Rogers, T., n.d. Everything You Need To Know About Polyethylene (PE). [online] Creativemechanisms.com. Available at: <https://www.creativemechanisms.com/blog/polyethylene-pe-for-prototypes-3d-printing-and-cnc>
Polymerdatabase.com. n.d. EVA. [online] Available at: <http://polymerdatabase.com/Polymer%20Brands/EVA.html>
Dragon Plate. 2019. DragonPlate | Engineered Carbon Fiber Composite Sheets, Tubes, and Structural Components | Made in the USA. [online] Available at: <https://dragonplate.com/an-overview-of-epoxy-resins