Carbon nano materials in crosslinked polyurethane and polyurea applications with optimized properties
Disclosed herein are novel methods to handling carbon nano materials and forming composite materials from carbon nano materials and polymers such as polyurethane and polyurea materials. Such novel methods provide a number of benefits to a polymer processor and end user of any resulting materials or products. As disclosed herein, methods of incorporating carbon nano materials into polymers can achieve benefits regarding electrical properties, modulus, and thermal stability as well as other benefits. However, enhancing and creating such improvements in material properties must be done with care because creating or enhancing one property does not always result in the creation or improvement in other properties. For example, thermal stability, electrical conductivity, and mechanical properties can be optimized in different ways, and at different loadings of differing carbon nano materials. Thus, it is necessary to carefully consider a number of factors when designing methods for incorporating carbon nano materials into polymers.
1. A polymeric composite, coating, or molded part comprising:
providing a carbon nanotube polyol blend and polyisocyanate, the carbon nanotube polyol blend formed from a carbon nanotube (CNT) masterbatch dispersion of carbon nanotubes and a polyol resin,
wherein the carbon nanotube (CNT) masterbatch dispersion is formed by dispersing between 0.1% and 15% (weight/weight) of CNT and a plasticizer under high shear mixing techniques to form a CNT masterbatch dispersion, and the carbon nanotube polyol blend is formed by mixing the CNT masterbatch dispersion and a polyol resin,
mixing the carbon nanotube polyol blend and polyisocyanate,
curing the polymer mixture to form a composite, coating or molded part,
wherein the resulting polymeric material has electrical resistivity of 10 4 Ω*cm −1 or more.
2. The composite of claim 1 , wherein the measured coating or part thickness is at least 30 mils.
3. The composite of claim 1 , wherein the carbon nanotubes are comprised of single walled carbon nanotubes.
4. The composite of claim 1 , wherein the carbon nanotube polyol blend has a polyol resin viscosity (25° C.) of between 1.2 and 1.4 Pa·s at 20 s −1 .
5. The composite of claim 1 , wherein carbon nanotube are in the carbon nanotube polyol blend in an amount under 1600 ppm (w/w).
6. The composite of claim 1 , wherein carbon nanotube are in the carbon nanotube polyol blend in an amount between 100 and 300 ppm achieves the percolation threshold for electrostatic dissipative conductivity (ESD).
7. The composite of claim 1 , wherein the stoichiometry ratio of isocyanate:polyol blend is 0.9-1.1.
8. The composite of claim 1 , wherein the plasticizer is present in the carbon nanotube polyol blend at about 2.8% (w/w).
9. The composite of claim 1 , wherein the polyol resin is present in the carbon nanotube polyol blend at about 93% (w/w).