Photophysical behavior and anisotropy of pyrene-labeled polyphenylene sulfide film with preferred orientation

Fluorescence recognition of polyphenylene sulfide (PPS) films is crucial for its role as a key structure and material. However, the luminescent performance and anisotropy of PPS fluorescent films remain unknown. In this study, we incorporated 1,6-dibromopyrene (Dbp) into the PPS to generate a series of Dbp-PPS fluorescent films with different drawing ratios. The Dbp-PPS film had a lower average lifetime (τ a = 0.56 ns) and quantum yield (Φ f = 0.014) compared to the Dbp-PPS resin powder, attributed to partially overlapped excimers. For uniaxially drawn films, tensile strength along the rolling (RD) and transverse (TD) direction was 57-67 MPa and 30-32 MPa, respectively. Meanwhile, the thermal expansion coefficient of the Dbp-PPS film in the RD was less than that in the TD as the uniaxial drawing ratio increased. The anisotropy of Dbp-PPS films is caused by the preferential orientation of molecular chains in the RD. Besides, the dielectric constant of these films ranged from 1.3 to 1.9 across a frequency band of 100 Hz to 10 MHz, with a DC breakdown strength ranging from 245 to 332 kV/mm and an AC breakdown strength between 162 and 268 kV/mm. This work provides fundamental guidance for developing PPS films with fluorescence recognition. The Dbp-PPS film is expected to be used in electronic and electrical applications such as film capacitors and flexible printed circuit boards. • The relations for drawing ratio, temperature, tensile strength, and UV-vis/FL of PPS films are made, respectively. • The Dbp-PPS films had an additional lifetime component versus the Dbp-PPS powder. • The tensile strength and thermal expansion coefficient of Dbp-PPS films exhibited anisotropy.