Additive manufacturing offers the ability to fabricate complex structures without the need for expensive tooling which is very attractive for manufacturing of structural composites. One limitation of additive manufacturing technologies hindering their adoption in high-performance structural composites is the lack of compatible high operating temperature thermosetting resins with robust thermo-oxidative stability. To address this limitation, a reactive melt extruded thermosetting polyimide filament was printed via fused filament fabrication (FFF). A crosslink chemistry has been designed with slow reaction kinetics at the printing temperature which allows printing in a similar manner to engineering thermoplastic filaments. A cure cycle for the as-printed uncrosslinked articles was developed to achieve full cure without loss of shape. The glass transition temperature of the fully cured resin is 250 °C. Comparing longitudinal and transverse tensile strengths of printed and cured coupons showed highly anisotropic behavior. Transverse and through-thickness properties for both uncured and cured printed coupons were nearly identical. The average measured tensile strength of printed and fully cured material was 86 MPa; 73% of fully cured compression molded strength. These results demonstrate the ability to 3D print high performance thermosets without changing commercially available FFF machines.

增材制造提供了制造复杂结构的能力，而无需昂贵的工具，这对于制造结构复合材料非常有吸引力。增材制造技术的一个局限是阻碍其在高性能结构复合材料中的采用，这是因为缺乏相容的，具有强大的热氧化稳定性的高工作温度热固性树脂。为了解决这个限制，通过熔融长丝制造（FFF）印刷了反应性熔融挤出的热固性聚酰亚胺长丝。已经设计了在印刷温度下具有缓慢反应动力学的交联化学物质，其允许以与工程热塑性长丝类似的方式进行印刷。已经开发出用于印刷的未交联制品的固化循环以实现完全固化而不会变形。完全固化的树脂的玻璃化转变温度为250°C。比较印刷和固化试样的纵向和横向拉伸强度显示出高度的各向异性行为。未固化和固化的印刷样板的横向和全厚度特性几乎相同。印刷和完全固化的材料的平均测得拉伸强度为86 MPa；完全固化的压缩成型强度的73％。这些结果证明了在不更改市售FFF机器的情况下3D打印高性能热固性塑料的能力。印刷和完全固化的材料的平均测得拉伸强度为86 MPa；完全固化的压缩成型强度的73％。这些结果证明了在不更改市售FFF机器的情况下3D打印高性能热固性塑料的能力。印刷和完全固化的材料的平均测得拉伸强度为86 MPa；完全固化的压缩成型强度的73％。这些结果证明了在不更改市售FFF机器的情况下3D打印高性能热固性塑料的能力。