Neat resin, adhesive and composite properties of reactive additive/PETI-5 blends

FETI-5 (5000 g mol(-1)) is a relatively new adhesive and composite matrix t hat exhibits good processability and excellent properties. However in the f abrication of complex composite parts (i.e, skin stringer and support frame s), better processability would offer distinct advantages, In an effort to improve the processability of PETI-5, a novel reactive additive was prepare d and used to formulate blends. The reactive additive is a mixture of relat ively simple phenylethynyl containing imides, As such, it exhibited solubil ity in a variety of solvents such as N-methyl-2-pyrrolidinone, a relatively low softening temperature (similar to 185 degrees C) and a low melt viscos ity (similar to 0.1-0.3 Pa s at 250 degrees C). Neat resin blends prepared by physically mixing imide powders of the reactive additive and PETI-5 were thermally and rheologically characterized. Blends were also prepared by mi xing NMP solutions of PETI-5 amide acid and the reactive additive (imide fo rm). These solutions were subsequently used to prepare adhesive film and un idirectional carbon fibre tape using unsized IM7 fibre, The reactive additi ve/PETI-5 blends were used to fabricate titanium adhesive panels and compos ites under 0.54 MPa or less for 1 h at 350-371 degrees C. The effect of rea ctive additive content on the physical, rheological, adhesive and carbon fi bre laminate properties was determined. One formulation exhibited a decreas e in melt viscosity (i.e, improved processability) without effecting open h ole compression, compression properties after impact or microcrack behaviou r. The neat resin, adhesive and composite properties of these reactive addi tive/PETI-5 blends and their cured polymers will he discussed.