Effect of molecular weight on properties of polyarylene ether nitrile‐based flexible copper clad laminate

Abstract A series of Polyarylene ether nitriles (PENs) with different molecular weights were synthesized and studied the effect of molecular weight size on the performance of PEN and PEN‐based flexible copper clad laminate (FCCL). It shows that these PENs have excellent thermal properties with T g > 200°C, T 5% > 500°C, and a long service life at 200°C (2.64 × 10 3 min, 95 wt% of the residual weight). The tensile mechanical properties of PENs increase gradually as the molecular weight of PENs increases, and the water absorption decreases with the increasing molecular weight of PENs. However, the peer strength of FCCL showed an opposite trend compared to the tensile properties of pure PEN, and the PEN‐2 shows the largest peer strength of 12.79 N/cm. Combining the thermal properties, mechanical properties, water absorption rate of PENs, and the peel strength and flexibility of FCCL, PEN‐2 is considered to be the most suitable for FCCL.