What is K and a constants in Mark Houwink equation?

In the Mark-Houwink equation, which describes the relationship between the intrinsic viscosity of a polymer and its molecular weight, ( K ) and ( a ) are constants specific to each polymer-solvent system. The equation is typically expressed as ([\eta] = K M^a), where ([\eta]) is the intrinsic viscosity and (M) is the molecular weight of the polymer. The constant ( K ) is related to the shape and interactions of the polymer in the solvent, while the exponent ( a ) reflects how the intrinsic viscosity scales with molecular weight, indicating the polymer’s branching or flexibility. These constants are determined experimentally for each specific polymer-solvent combination.