Polyester

Polyester Polyesters are among the basic polyols used in polyurethane applications. They are advantageous due to their good adhesion properties, solvent resistance and superior mechanical values. The viscosity values depending on shear rate in polyester polyols using various CAB-O-SIL types are shown in figure 2a. Accordingly, the highest viscosity increase was observed with CAB-O-SIL TS 720 and followed by CAB-O-SIL TS-530. As with polyethers, CAB-O-SIL TS 610 and CAB-OSIL M5 provided only slight thickening in polyesters as well. As shown in figure 2b, product selection should favor CAB-O-SIL TS 530 when thixotropy and average dispersion time balance are considered. Polybutadiene Polybutadienes are one of the main polyol types used in polyurethane applications. Polybutadiene polyols are advantageous due to their flexibility, good adhesion and low moisture absorption. The viscosity values depending on shear rate in polybutadiene polyols using various CAB-O-SIL types are shown in figure 3a. Accordingly, CAB-O-SIL TS-720 is seen as the most effective thixotropic agent. CAB-OSIL TS-530, TS-610 and M-5 types provide virtually no thickening in this type of polyol. If dispersion time and clarity are important criteria, the use of CAB-O-SIL TS-610 or CAB-OSIL TS-530 is suitable, as shown in figure 3b. Summary To achieve the desired viscosity in all components of PUR, good thickeners are required because this allows good mixing and consistent adhesive system application. Dispersion ease provides formulators with shorter processing time and lower cost opportunity. On the other hand, clarity is important for those producing unfilled systems and can also benefit all formulators as it serves as an indicator of air release or bubble formation.