Thermally degradable polymeric fibers

A method of making a microvascular system, comprising:

• forming a composite comprising:
• a solid polymeric matrix, and
• a woven structure in the polymeric matrix, the woven structure comprising a plurality of reinforcing fibers, and a plurality of sacrificial fibers having a degradation temperature of from 180 to 250° C.;
• where the sacrificial fibers comprise a poly(hydroxyalkanoate) and at least 0.1 wt % of a metal compound selected from the group consisting of a tin salt of a mono- or di-carboxylic acid, and scandium triflate (Sc(OTf)3);
• heating the composite to a temperature of from 100 to 250° C.;
• maintaining the composite at a temperature of from 180 to 250° C. for a time sufficient to form degradants from the sacrificial fibers;
• and
• removing the degradants from the composite to provide the microvascular system.

A method of making a degradable polymeric fiber, comprising:

• combining:
• a fiber comprising a poly(hydroxyalkanoate), and
• a composition comprising a fluorinated fluid and a metal compound selected from the group consisting of a tin salt of a mono- or di-carboxylic acid, and scandium triflate (Sc(OTf)3);
• maintaining the fiber and the composition together at a suitable temperature and for a time sufficient to provide a concentration of the metal compound in the fiber of at least 0.1 wt %;
• and
• separating the fiber from the fluorinated fluid to form the degradable polymeric fiber having a degradation temperature of from 180 to 250° C.