Building and construction sector: An industry relies on plastics

Polymers are as diverse as their chemical composition. Plastics come in hard, soft, flexible, brittle, opaque, transparent - just as required. They impress with their durability, cost-effectiveness, impermeability to water, high formability, corrosion resistance and low weight. They defy heat, light and weather. This makes them the ideal building material - and an environmentally friendly alternative to other materials.

The construction industry has realized this for a long time. The building and construction sector uses one fifth of the ten million metric tons of plastics used in Europe every year. Half of this fifth is in plastic pipes. The other half is used, for example, to make insulating materials, window frames, cable insulation, joint compounds and electrical outlets. A total of around 50 different plastics are used in the manufacture of these products typical of the construction industry, the three main groups being polyvinyl chloride (PVC), polyethylene (PE) and polystyrene (PS).

Plastic found its first application in the construction industry around 90 years ago: in pipes made of hard PVC. Window frames made of PVC followed in the 1950s. Pipes and things like construction films were already being produced from PE by then. And at the latest with BASF's invention of Styropor in 1952, synthetic polymers became indispensable in the construction industry. Before that time, the only chemical plastic available was the dark brown to black bakelite - created by the reaction of phenol and formaldehyde, discovered in 1905 by the Belgian chemist Leo Hendrik Baekeland.

For years, compounding has been used to make the plastics used suitable for even more applications in the construction industry by mixing them with additives. Glass fibers (GF) and carbon fibers (CF) are an important keyword here. They give the plastic greater strength and rigidity. Fiber-reinforced plastics such as GRP and CFRP are used, for example, in manhole covers, light wells, gratings and window frames. The latter, for example, become narrower and offer more light incidence due to the correspondingly larger glass area of the window.

In concrete construction, CFRP was already being used in place of steel reinforcement in the 1990s. Because CFRP does not rust, slimmer concrete components with equivalent structural properties can be produced in this way. This in turn means more economical material consumption. To the benefit of costs and the environment.

Speaking of the environment, it has long been a question not only of benefiting from the advantages of plastics in construction, but also of producing them sustainably. On the one hand, existing plastics are being recycled; on the other, new plant-based (from corn, sugar cane, algae, etc.) bioplastics are being designed. Kurtz Holding researchers, for example, have developed radio frequency (RF) technology that enables processing of particle foams using electromagnetic waves in the radio frequency range. Compared to conventional steam processing, this can save up to 70 percent CO2, 90 percent energy and 100 percent water, depending on the material used. The new technology is also suitable for bio-based plastics such as corn-based particles, which the company's developers are currently working on. BASF has already developed a biodegradable particle foam in 2018, while the company Armacell has developed a particle foam made from 100 percent recycled PET bottles.

It's worth taking a look at other impressive ideas for making materials needed in construction sustainable. The Dutch company Pyrasied, for example, offers acrylic glass made from recycled material. In 2017, Kenyan materials engineer Nzambi Matee succeeded in developing a process to produce bricks from recycled plastic. They are five times as hard as concrete. And the Thuringian company PolyCare is dedicated to producing blocks from polymer concrete.