These studies show that laser ablation, a technique widely used to deposit thin films of inorganic materials is also a simple and highly versatile tool for studying polymer decomposition. The use of laser ablation and fast resistive heating to control the degradation kinetics of vinyl polymers is illustrated here. Although polypropylene and polyvinyl fluoride are commonly believed to pyrolyze via random scission producing little monomer, our results demonstrate that in ablative decomposition they unzip with large monomer yields. We propose heating rate and final temperature to be the controlling factors in determining the thermodynamics and kinetics of decomposition reactions.