Poly(1,3,5-hexahydro-1,3,5-triazine)s (PHTs) are a recently-discovered class of thermosets, whose network formation proceeds by condensation polymerization of aromatic diamines with formaldehyde, through hemiaminal and imine intermediates. Most interestingly, 4,4’-oxydianiline (ODA)-based PHT represents a high modulus and recyclable resin. However, like most other highly-crosslinked resins, PHTs synthesized using monomeric diamines like ODA, are brittle materials, limiting their application space. One approach to forming recyclable high-performance thermoset polymers while tailoring the materials characteristics, is to covalently incorporate functional groups that are known to have the desired properties into the recyclable hexahydrotriazine network in a single step. To this end, PHTs were modified during the process of vitrification using a reactive blending technique. Two strategies were employed: (i) the incorporation of a monomer or oligomer that contains network forming end-groups (i.e. amines) that is integrated into the network via hemiaminal chemistry and (ii) the incorporation of functional monomers bearing reactive end-groups (i.e. no amines) capable of self-polymerization as well as insertion by copolymerization with the PHT-forming reagents to form mixed networks. Judicious choice of co-monomer or co-polymer based on reactivity allowed concurrent or subsequent orthogonal condensations, forming polymer and hexahydrotriazine linkages in “one-pot”. Each strategy produced homogeneous materials and allowed mitigating the thermal and mechanical properties of the PHT material in an easy and cost-effective manner.

Structure-property relationship of poly(1,3,5-hexahydro-1,3,5-triazine) materials modified by reactive blending

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.