A method for converting biomass having a water content of at least 50% into gaseous products includes providing a reactor containing supercritical water and a salt melt. The vehicle also includes a controller programmed to control a rate of change of a regenerative braking torque limit during a transmission downshift that occurs during a regenerative braking event based on a change in speed of an output shaft of the powertrain caused by the transmission downshift. The at least one \u03b1-functional unsaturated monomer of the invention comprises two leaving groups L1 and L2, wherein at least one of the leaving groups L1 and L2 of the at least one \u03b1-functional unsaturated monomer is part of the nonaromatic unsaturated structure C\u2550C\u2014C\u03b1-L.