"Cyanate esters are a relatively new generation of thermosetting resins that exhibit considerable tolerance in high service temperatures where the effects of moisture and micro-cracking due to thermal cycling loading are important. They exhibit low moisture absorbency, whilst retaining useful processing characteristics, e.g. cure temperatures, handling and composite processing by pre-preging or by resin transfer molding. In particular, the improvements over epoxies are good toughness, lower moisture absorption, higher glass transition temperatures at lower cure temperatures and increased resistance to micro-cracking. Consequently, cyanate ester based composites are exceptional candidate materials for parts used in aircraft or rotorcraft components that are subjected to a complex history of temperature, moisture and other environmental conditions. Nevertheless, the long-term exposure of cyanate ester based composite materials to those harsh environmental conditions and the respective degradation of their properties defined as material ageing process is not yet fully studied and understood. This aspect limits the further utilization of such materials in aeronautical applications. SPECIMEN project aims to fill this missing knowledge gap and create specific technical guidelines. Taking into account the technical requirements provided by the topic manager, SPECIMEN project will provide CSJU a complete study that will include a Material Screening Procedure, a Manufacturing Process Plan, the methodologies for studying ageing process using accelerated testing protocols, the durability performance characteristics of selected materials and a Compliance and Optimization Study for selected materials. The deeper understanding of the degradation in harsh environments using advanced material screening/testing procedures, accompanied with optimized manufacturing protocols will clarify issues concerning the inputs, outputs and nuisances during all three phases of aircraft life. Both participants that form the SPECIMEN consortium have strong background on processing-characterization of cyanate ester based materials and have extensive experience and infrastructure on ageing studies, which originates from their participation in various EC, ESA and national projects."