Photo-curable polyimide-like materials, and method of making
A method of making a polyimide (PI)-based material. In one embodiment, the method begins by dispersing a polyamic acid (PAA) oligomer and photo-initiator into a photo-reactive monomer to form a liquid resin. In contrast to the above-described prior art, the liquid resin is substantially devoid of any non-reactive solvents. Electromagnetic radiation is then applied (e.g., in a 3D printing operation) to solidify the liquid resin and to substantially form a interpenetrating polymer network (IPN) in which the PAA oligomer is entangled within the network formed by the photo-reactive monomer but remains substantially independent and un-crosslinked from the PAA oligomer. Thereafter, the PAA-based IPN is thermally cycled to form a polyimide-based IPN.
1 . A method of making a polyimide (PI) based material, comprising:
dispersing a polyamic acid (PAA) oligomer and a photo-initiator into a photo-reactive monomer to form a liquid resin, wherein the liquid resin is substantially devoid of any non-photoreactive solvents;
applying electromagnetic radiation to solidify the liquid resin and to substantially form a PAA-based interpenetrating polymer network (IPN) in which the polyamic acid oligomer is entangled within the network formed by the photo-reactive monomer; and
thermally cycling the PAA-based IPN to form a PI-based IPN.
2 . The method as described in claim 1 , wherein the polyamic acid and the photo-reactive monomer in the PAA-based IPN are substantially independent and un-crosslinked.
3 . The method as described in claim 1 , wherein the photo-reactive monomer comprises one or more photo-reactive components.
4 . The method as described in claim 3 , wherein the photo-reactive monomer is one of: N,N-dimethyacrylamide (DMAA), and a photo-reactive amine.
5 . The method as described in claim 1 , wherein a loading of the PAA oligomer in the liquid resin is about 70%.
6 . The method as described in claim 1 , wherein a wavelength of the electromagnetic radiation is between about 350 nm and 7000 nm and is applied in association with an additive manufacturing operation.
7 . The method as described in claim 6 , wherein the additive manufacturing operation is a vat photopolymerization.
8 . The method as described in claim 1 , wherein thermal cycling is at or below one of: 200° C., 250° C. and 300° C.
9 . The method as described in claim 8 , wherein pyrolysis of a polymer formed from the photo-reactive monomer is avoided.
10 . The method as described in claim 1 , wherein the IPN is a semi-IPN.
11 . The method as described in claim 1 , wherein the electromagnetic radiation is one of: deep UV, light UV, visible and near IR.
12 . A polyimide (PI) based material manufactured according to the following process steps:
dispersing a polyamic acid (PAA) oligomer and a photo-initiator into a photo-reactive monomer to form a liquid resin, wherein the liquid resin is substantially devoid of any non-photoreactive solvents;
applying electromagnetic radiation to solidify the liquid resin and to substantially form a PAA-based interpenetrating polymer network (IPN) in which the polyamic acid oligomer is entangled within the network formed by the photo-reactive monomer; and
thermally cycling the PAA-based IPN to form a PI-based IPN.