Method for treating polyimide

A direct formed crystalline polyimide product wherein the polyimide comprises a first repeat unit derived from pyromellitic dianhydride (PMDA) and a second repeat unit derived from 4,4′-oxodianiline (4,4′-ODA), and wherein the direct formed crystalline polyimide product:

• does not comprise an encapsulated filler, comprises 0 wt % to 0.5 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 80.0 MPa or greater;
• or
• comprises 10 wt % to 20 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 0 wt % to 0.5 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 63.0 MPa or greater;
• or
• comprises 20 wt % to 60 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 0 wt % to 2.0 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 50.0 MPa or greater;
• or
• comprises 10 wt % to 20 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 5 wt % to 15 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 52.5 MPa or greater;
• or
• comprises 20 wt % to 60 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 10 wt % to 20 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 39.5 MPa or greater.

A hot isostatically pressed crystalline polyimide product, ram extruded crystalline polyimide product, or hot compression moulded crystalline polyimide product, wherein the polyimide comprises a first repeat unit derived from pyromellitic dianhydride (PMDA) and a second repeat unit derived from 4,4′-oxodianiline (4,4′-ODA), and wherein the hot isostatically pressed crystalline polyimide product, ram extruded crystalline polyimide product, or hot compression moulded crystalline polyimide product:

• does not comprise an encapsulated filler, comprises 0 wt % to 0.5 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 87.0 MPa or greater;
• or
• comprises 10 wt % to 20 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 0 wt % to 0.5 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 66.0 MPa or greater;
• or
• comprises 20 wt % to 60 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 0 wt % to 2.0 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 52.5 MPa or greater;
• or
• comprises 10 wt % to 20 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 5 wt % to 15 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 49.5 MPa or greater;
• or
• does not comprise an encapsulated filler, comprises 10 wt % to 20 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 59.0 MPa or greater;
• or
• comprises 20 wt % to 60 wt % of an encapsulated filler relative to the weight of the polyimide, comprises 10 wt % to 20 wt % of an additive relative to the weight of the polyimide, and has a tensile strength of 39.5 MPa or greater.