Polymer processing systems and methods employing pulsed heating

A system for processing a reactant, the reactant comprising one or more polymers, the system comprising:

• a reactor comprising a plurality of pores, a plurality of microchannels, or both;
• a heating system configured to heat at least the reactor;
• and
• a controller operatively coupled to the heating system, the controller comprising one or more processors and computer-readable storage media storing instructions that, when executed by the one or more processors, cause the controller to control the heating system to subject the reactant to multiple consecutive processing cycles, each processing cycle comprising a first period with heating applied and a second period immediately following the first period with no heating applied,
• wherein a duration of each processing cycle is less than or equal to 10 seconds,
• a duration of each first period is less than 1 second,
• the reactor is constructed to transport melted reactant at a first end of the reactor into the reactor via capillary action, and
• one or more of the processing cycles are effective to convert at least some of the reactant into one or more first products at a second end of the reactor opposite the first end.