Polyurethane dispersions (PUD) are composed of distributed(dispersed) polyurethane particles in water with the aid of a dispersing agent added between the polymer chain. It is preferred in many sectors such as automotive, construction, textile, packaging, registration etc. because it is a high performance and green product.
Its usage is increasing day by day in national and international area. This increase is a choice arising from legal requirements due to performance and humanenvironmental health.
We will briefly explain the performance and cost issues related to PUD products and examine the resin and membrane products we offer for the construction industry.
Performance Approach
Polyurethane dispersion products primarily provide information about the raw materials used in, the polymer chain and their performance. The choice of polyol and isocyanate type used is of great importance.
The raw materials to be used are adding different properties such as mechanical and chemical resistance to PUD products. Some properties of PUD products according to the polyol types used are simplified shown in the following table.
In addition to the polymer structure, additional performance enhancing additives are added to the PUD systems. Various cross-linkers, adhesion promoters, surface modifiers, fireproof materials, touch additives are some of them.
Cost Approach
As mentioned above, PUD systems are very important for manufacturers due to their high performance and environmental factors, but their cost is higher than traditional acrylic emulsions, which limits its uses. For better costs and performance, using it with acrylics is preferred.
This is done in two ways;
1) Physical mixing of PUD resins and acrylics by formulators or PUD resin manufacturers,
2) PUD Resin manufacturers have added acrylics to the polymer chain during synthesis.
With these and similar processes, PUD-based formulas can be reduced the costs up to optimum price-performance level with additional additives. Of course, they will not have the same performance as pure PUD resins. PUD use is increasing with these operations in many sectors.
In areas where acrylic, etc. polymers are not sufficient alone, PUD makes role for itself with its superior quality.
As The PURIN, we produce the water-based polyurethane materials with PUD Technology and provide our clients with competitive prices with the investments we made in Turkey. They can produce high performance products without having to add other polymers.
Water Insulation Membranes
Waterproofing is the most critical issue that determines the life of a building. The skeleton that holds the structures is steel. On the other hand, steel will rust in the water and its performance will decrease. This weakening of steel causes our buildings to collapse over time.
For this reason, waterproofing is the usual process to extend the life of buildings. Waterproofing processes are carried out in the form of some water-repellent additives thrown into the concrete, polyurethane injections used in the cracks in concrete and sliding- based liquid membranes.
Bitumen derivatives, acrylics and polyurethanes are mostly used in waterproofing membranes. In terms of performance, polyurethane materials are far superior to other products. When we examine polyurethane products, mostly we use single component air-reactive polyurethane prepolymer based filled materials.
As reactive products these materials have advantages and disadvantages. Its most important advantage is its high bonding with ionic bonding with the surfaces.
The disadvantages of polyurethane prepolymer based insulation membranes are;
• Short shelf life,
• No application on damp surfaces,
• Limited UV resistance,
• Production challenge for manufacturers,
• The system contains solvent.
PURIN has been producing and delivering high performance polyurethane prepolymer resins for waterproofing membranes since its establishment in 2015.
However, we have been producing Water Based Polyurethane Dispersion (PUD) products with PUD Technology since the beginning of 2018 with our innovative view and strong R&D experience. We produce two different resins for flexible insulation systems for waterproofing and for hard-transparent ceramic surfaces.
1) Flexible Waterproofing Membrane Resin:
This product is a polyether-based polyurethane dispersion resin. It is a non-yellowing, flexible product with aliphatic structure which can be converted into membrane product with additives such as filling into the resin. Here are some test results that describe the resin.
2) Hard Water Insulation Membrane:
Another product is a transparent material for ceramic surfaces that we define as hard elastic. Structurally, it is an aliphatic polyurethane dispersion based on polycarbonate polyol.
This product is ready for use directly as before, not to add any filling to system. It protects the visuality of the surfaces applied on it such as ceramic surfaces with its transparent feature. Here are some test results that identify the product.
The advantages of water- based polyurethane dispersion insulation products over the others can be summarized as follows;
High Mechanical Performance: Very high mechanical performance compared to non-polyurethane products. Has similar performances with polyurethane prepolymers,
• High Chemical Performance: Hydrolysis resistance is very high, does not decompose in aqueous environments,
• Can Be Applied to Damp Surfaces: Polyurethane prepolymer based systems are very sensitive to moisture in the surfaces. Application to damp surfaces is not possible, but PUD membranes already contain water. Therefore, it can be applied to any kind of damp or even wet surfaces easily,
• No UV Yellowing: Most polyurethane prepolymer based products are aromatic and use UV reinforcing additives to delay yellowing, but they will become yellowing after a certain period of time. PUD membrane systems are aliphatic products due to their structure. Therefore, they have no yellowing problem,
• Environment Friendly Product: Polyurethane prepolymer based products contain flammable and combustible solvents. Exposes risks for environment and human health. PUD membranes are waterbased systems and do not pose a risk to human and environmental health.
• Ease of Production: Production of polyurethane prepolymer based products involves risks. Interaction of the product with moisture, increase the heat and increase of reactivity at the same time, packaging, being solvent system, shelf life and stock costs and the need to use special additives in production and high costs of these additives are parameters that make production difficult and non-economical. In PUD membranes, the resin is water-based and non-reactive.
Therefore, none of the above risks are involved. It is as easy to produce as paint formulas.
• Long Shelf Life: Polyurethane prepolymer materials continue to react with moisture. When you enter the filler into the prepolymer, the moisture from the filler must be removed. For this, you need to use special chemicals.
However, the viscosity of the reactive products in the package increases over time, and in the absence of the necessary additives, the product may solidify in the package.
Therefore, since the resin is not reactive in these products in PUD membrane systems, the shelf life of the product can be obtained as long as 12-24 months without the need of special additives.
• Cost Advantage: Polyurethane prepolymer based membrane products are generally aromatic and UV boosters are used. Considering the cost of this system and the stock costs of the special additives used, the cost of PUD membranes to the manufacturers is similar. Of course, the PUD membranes are aliphatic, which offers great advantages.
If you use an aliphatic based resin on polyurethane prepolymer, PUD membrane costs will definitely be lower. As a result, PURIN Polyurethane continues to produce new and special products with PUD Technology.
Sometimes the products designed by our technical team and sometimes developed according to the demands of our customers add differences to the market.
We design sustainable processes with our environmentally and human health sensitive positions and providing cost advantages to our customers. We offer our PUD products with national and international certificates to all our customers both in Turkey and in the region.
İbrahim Kecin – Yüksek Kimyager – Chemist, M. Sc. Genel Müdür – General Manager PURİN Poliüretan – PURIN Polyurethane
Ayşenur Dede – Ar-Ge Müdürü – R&D Manager PURİN Poliüretan – PURIN Polyurethane
