Poly(phthalidylidenearylene)s. Effect of pressure on the conductivity of poly(3,3-phthalidylidene-4,4′-biphenylylene)

Poly(3,3‐phthalidylidene‐4,4′‐biphenylylene) (PPB) was considered to be a polymer containing pressure‐sensitive moieties as repeating units in the main chain. The effect of pressure on the properties of PPB was studied. Thin films of the undoped polymer were found to become conductive under slight pressure. The conductivity increases from 10−14 up to 10−3 Ω−1 · cm−1 under a pressure of about 3 · 105 Pa (0,3 kg/cm2). An effective method is used to visualize the pattern of conducting sites. These may be represented by channels (or domains) in the polymer film.