5- The following equation describes the temperature dependence of x for the PMMA/butanol polymer/solvent system: x = -0.015 + 43.23/ T (with T in C). For what range of temperatures will a very high molecular weight PMMA completely dissolve in butanol? 6- The Young's modulus of a rubber sample is E = 4.0 MPa and its density 1000 kg/m at a temperature of T = 300 K. Estimate the molar crosslink density and the average molecular weight between crosslinks