Abstract
A linear thermoplastic polyimide, LARC-TPI was developed at NASA Langley Research Center which showed promise as a high temperature adhesive for applications in aircraft and spacecraft. Under the license agreement with NASA, Mitsui Toatsu Chemicals, Incorporated (MTC), Tokyo, Japan is now commercially producing LARC-TPI in the forms of varnish, film, powder and prepregs.
The use of meta-substituted aromatic diamine in the preparation of LARC-TPI has been a major advancement toward improving the processability by lowering the glass transition temperature while retaining mechanical, thermal and electrical properties inherent to polyimide.
Many application studies have been made on LARC-TPI film and powder including adhesive strength, thermooxidative stability and flow properties.
LARC-TPI is being evaluated and used primarily as structural adhesive for bonding metals, composites and ceramics. LARC-TPI is also being evaluated as an adhesive in the large-area bonding of polyimide film to produce flexible, 100% void-free laminates for flexible circuit application. LARC-TPI film laminates with copper for FPC application can withstand a dip-in 300°C soldering and retains sufficient peel strength.
LARC-TPI film also shows potential as a material for making high temperature films with good adhesive and electrical properties. The film shows excellent potential as organic insulators in many electrical applications at temperature to 300°C.
