Embedded single carbon fibre to sense the thermomechanical behavior of an epoxy during the cure process

A new approach that uses a single carbon fibre for sensing the thermomechanical behavior of an epoxy during the cure cycle is presented. By recording and analyzing the electrical resistance and temperature history of a carbon fibre embedded inside an epoxy specimen during the cure cycle, the interaction between the carbon fibre and the surrounding polymer can be revealed. Compared with reported TMA and DMA results, this embedded carbon fibre sensor approach successfully detects the glass transition zone covering the final transition temperature, the main transition temperature, and the starting transition temperature that respectively have similar values as: (i) Tg corresponding to the abrupt change in CTE, (ii) Tg by storage modulus (E′) onset, and (iii) the upper temperature limit for the linear relationship between E′ and the temperature. The future applications for this sensor method are also discussed.