Polymers with a triggered decomposition are attractive for an array of applications ranging from patterning to transient packaging materials, as well as for environmental protection. This work showed for the first time UV and thermally triggered transience in fiber mats using poly(propylene carbonate) (PPC) composites. The electrospun PPC-composite fiber mats combine excellent decomposition performance (because of the high surface to volume ratio) with high stiffness and thus represent a new class of materials enabling innovative applications, such as transient filter materials and short-time plant protection materials, as well as temporary lightweight materials for aerospace engineering. Thermally and UV-triggerable additives (protected acids or base) have been used in different concentrations to tune the transience performance of the fiber mats over a wide range (75-212 °C). The addition of organo-modified clay (OMMT) enhanced mechanical stability and prevented shrinkage at room temperature. Different annealing methods have been used to improve the mechanical properties even further (tensile strength = 2-12 MPa, Young's modulus = 55-747 MPa) making these fiber mats attractive for a broad field of applications. An Ashby plot of Young's modulus versus degradation temperature for electrospun fiber mats is shown, revealing much lower degradation temperatures with higher moduli for PPC composites compared to other electrospun polymers.

This work reports the first transient electrospun nanofiber mat triggered by UV-irradiation using poly(propylene carbonate) (PPC)/poly(phthalaldehyde) (cPPA) polymer blends. The ability to trigger room temperature transience of nanofiber mats without the need for additional heat or solvent expands its utility in nonbiological fields, especially for transient electronic devices. The addition of a photo-acid-generator to the system, working in combination with UV light, provides an acid source to enhance degradation because both polymer backbones are acid-sensitive. Electrospinning enables the production of PPC/cPPA composite nanofiber mats capable of significant degradation upon exposure to UV radiation while maintaining relatively high mechanical properties. An acid amplifier, an autocatalytically decomposing compound triggered by acid, was used to generate more acid and accelerate nanofiber degradation. The electrospun fiber mats can be post-annealed to achieve an improved mat with a mechanical strength of ∼170 MPa.