Preparation and characterization of polyurethane materials containing natural polyols

Polyurethanes are widely used in applications such as coating, insulation, automotive, textile, decoration with properties such as impact resistance, chemical resistance and flexibility. They are classified as rigid, flexible, integral (semi-flexible) systems according to their usage in the sector. The use of polyols and diisocyanates with various chemical and physical properties in their production allows the production of polyurethane products with different properties. Most of the raw materials used in polyurethane synthesis are from petrochemical sources. Recently, it has been seen studies in the field of polymer chemistry are focused on renewable raw materials. It is preferred that chemical raw materials be biodegradable and economical. In this study, as an alternative to petrochemical products, it is aimed to use polyols based on vegetable (natural) and vegetable oil based polyols for economic and petrochemical dependency reduction. Long and flexible aliphatic chains which have strength by forming cross-linkages in the polyurethane structure with triglycerides in natural and oil-based polyols (sorbitol-glycerol based polyethers, castor oil, glycerol etc.) provide superior properties to polyurethane structure by increasing impact resistance. The polyurethanes containing natural polyols are reinforced with inorganic fillers to obtain products with more economical and various mechanical properties and the effects of fillers and natural polyols on the product properties have been investigated. Polyurethane films were obtained by one-shot technique. Toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI) as diisocyanates, polypropylene glycol (PPG) of petrochemical-derived as polyol, sucrose as natural polyol, sorbitol, glycerol based polyether polyols and castor oil were used. Dibutyl-tin-dilaurate (DBTDL) was used as the catalyst. Calcite, barite and talc are preferred as inorganic fillers. The characterization of the polyurethane films after curing was carried out by Fourier Transform Infrared Spectroscopy (FTIR). The mechanical analyzes were carried out with a tensile testing machine. Films obtained from the combination of PPG / TDI, PPG / MDI in the study a comparison of the mechanical properties of the PPG-natural-origin polyol mixture with the TDI and MDI in combination with the film obtained. In the same combinations inorganic filler was added and the mechanical properties were compared with the films without addition. In the characterization analyzes, it was observed that natural polyols increased cross-linking of polyurethane structure compared to petrochemical-derived polyols to increase material strength. In addition, it has been found that the strength of the castor oil increases as well as the elasticity property. It has been found that the conditioning test applied to films obtained with inorganic fillers results in less shrinkage compared to unfilled films.