High-Performance Polyurethanes for Technical Textiles

With the Covid-19 pandemic affecting the entire world in recent times, the importance of all technical textiles, particularly those used in the healthcare sector, is steadily increasing.

Hospital bed sheets, protective pads, medical drapes, protective suits, field hospital tents, raincoats and patient protection wear, and other technical textiles are classified as leading coated textiles. Coated textiles are textiles coated with polymers that provide high mechanical and chemical values depending on the properties of the polymer in their structure. Solvent-based polyurethanes are preferred in technical textiles due to their high mechanical and chemical properties. [caption id="attachment_102903" align="aligncenter"] Figure 1. Polyurethane synthesis scheme and structure[/caption] Solvent-based polyurethanes have no branching in their polymer structure. However, these polymers do not exist as single chains in the structure. Structures present as single chains are held together by hydrogen bonds forming clusters, and these hydrogen bonds in the structure directly contribute to the physical properties of the product. Due to the effect of hydrogen bonds, very high adhesion values are achieved with textiles. [caption id="attachment_102904" align="aligncenter"] Figure 2. Hydrogen bonds between polyurethane and textile[/caption]

In Technical Textile Applications, the advantages of using polyurethane as a coating material can be listed as follows:

• Polyurethane coatings have very high tensile/tear/impact resistance and excellent abrasion resistance, • Good resistance to adverse weather conditions, • Maintains flexibility even at low temperatures, • Coating properties can be prepared as desired, • Polyurethane coatings can offer a wide range of enhanced properties including breathable, microporous characteristics, • Polyurethane coatings can be dry-cleaned (without the use of plasticizers), • Polyurethane coating generally provides very good adhesion to textile and high elongation and excellent flexibility properties. Depending on the needs at the site where the final product will be used, various processes exist for applying the coating to the textile material. The basis of these coating processes is the removal of the solvent from the polyurethane mixture (polyurethane, solvent, dye and additives, etc.), resulting in layer-by-layer film formation.

Some of these processes include:

• Transfer Coating: Transfer of polyurethane applied to patterned/plain carrier paper onto textile using adhesive polyurethane, • Direct Coating: Application of polyurethane directly to the textile surface with a doctor blade.   [caption id="attachment_102917" align="aligncenter"] Figure 5. Transfer coating process scheme[/caption]   İnterplast Kimya Research and Development Center offers solutions for solvent-based polyurethanes, dyes and additives with superior performance properties for the technical textile sector, particularly important during the Covid-19 pandemic; • Hospital bed sheets, • Medical drapes, • Military tent tarps, • Raincoats, • Coveralls, • Protective pads for products such as these. With PURANEX Series Products Synthesized; Following tests conducted at internationally accredited laboratories of industrial trials made with PURANEX series polyurethanes developed by İnterplast Kimya Research and Development Center and COLANEX T series pigment pastes; Regarding the performance values provided by İnterplast Kimya Research and Development Center for the technical textile sector; • With PURANEX series polyurethane group for transfer coating, direct coating and lamination applications, • With COLANEX series dye group containing no restricted chemicals, • With ECO series polyurethane group containing no dimethylformamide (DMF), it provides solutions to domestic and foreign customers' needs.     Lale Şen Çetin Research and Development Center Manager İnterplast Kimya San. ve Tic. A.Ş.