| abstract |
Disclosed herein are hard and flexible compositions, i.e., compositions which have a flexural modulus that is less than the value that is expected based on the composition's hardness. The compositions preferably have a hardness/modulus relationship represented by the formula n H ≧11.889 Ln ( M )+47,n n where H is the hardness of the composition, in JIS-C, and M is the flexural modulus of the composition, in ksi; or a softness/stiffness relationship represented by the formula n if M <110, then H ≧8.5218 Ln ( M )+32.5n n if M ≧110, then H ≧72.5,n n where H is the hardness of the composition, in Shore D, and M is the flexural modulus of the composition, in ksi. |