The photocleavage of o-nitrobenzyl moieties drives shape transitions from globular to wormlike in stimuli-responsive homografted and binary heterografted molecular bottlebrushes.

Carbohydrate-derived monomers were synthesized, and thiol–ene photopolymerization was employed to produce thermoset films and fibers from the biobased dienes isosorbide 10-undecenoate (IU) and glucarodilactone 10-undecenoate (GDLU) and multifunctional thiols. The resulting materials, comprising up to 94% biorenewable content, were flexible and cross-linked and had mechanical and thermal properties that varied with IU and GDLU content (e.g., rubbery plateau storage moduli = 6.1 to 10.5 MPa at 40 °C above the glass transition temperature; glass transition temperatures = −9.9 to 27 °C by differential scanning calorimetry; degradation temperatures = 238 to 347 °C by thermogravimetric analysis). By combining electrospinning with in-situ UV irradiation and carefully controlling the monomer mixture viscoelasticity and orifice-to-collector flight time, we produced uniformly cured fibers directly from the monomer feed when the ene monomers contained either 100% GDLU or 50% GDLU/50% IU. The resulting GDLU-containing thermoset films and fibers were readily decomposed into soluble small molecule fragments in basic aqueous media due to the intrinsic degradability of the GDLU unit. This study highlights the potential advantages of using carbohydrate-derived monomers for producing thermoset fibers and nonwovens that are both renewable and degradable.

Tunable and degradable crosslinked-polyanhydride networks from renewably derived itaconic anhydrides and multifunctional thiols have been developed.