Thermosetting compositions and forming three-dimensionalobjects therefrom

A composition for forming a three-dimensional object via an additive fabrication process comprising:

• a. from 30 to 100 wt %, based on the total weight of the composition, of a first network-forming component comprising:
• i. from 19.95 to 80 wt %, based on the total weight of the first network-forming component, of a TPA-based polyester comprising a backbone and having a number average of at least 2 polymerizable groups, wherein the backbone comprises the reaction product of one or more polyacids including a terephthalic acid and a polyol, wherein the polymerizable groups comprise acrylate, methacrylate, epoxy, oxetane, hydroxyl, itaconate, vinyl ether, allyl ether, maleate, or fumarate, and wherein the TPA-based polyester has a number average molecular weight of from 800 to 10000 g/mol and a Tg of at least 25° C.;
• ii. from 19.95 to 80 wt %, based on the total weight of the network-forming component, of one or more first network monomers having a number average of 0.95 to 1.1 polymerizable groups that are able to (co)polymerize with the polymerizable groups of the TPA-based polyester, wherein a linear polymer formed from the one or more first network monomers has a Tg of at least 25° C.;
• and
• iii. from 0.05 to 5 wt %, based on the total weight of the first network-forming component, of one or more first network initiators capable of initiating the polymerization of the TPA-based polyester and the first network monomer;
• and
• b. a second network-forming component comprising one or more second network compounds comprising polymerizable groups that do not (co)polymerize with the polymerizable groups of the TPA-based polyester, and a second network initiator for initiating the polymerization of the one or more second network compounds.