Tuning the structure of pendant groups in poly(α‐arylTMC)s: A pathway to high glass transition temperature

Aliphatic polycarbonates have been explored as environmentally benign alternatives to aromatic polycarbonates. Improvements to the glass transition temperature ( T g ) of aliphatic polycarbonates have been pursued by several groups. We recently showed that attaching a pendant aromatic group to poly(TMC) can enhance the T g . Also, we have shown that para substituents on the pendant group have an impact on the T g . Here, we have explored the role of bulky pendant groups and the effect of substituent position on the pendant aromatic ring. We prepared novel naphthalene‐derived poly(TMC)s as well as 2‐Br‐substituted poly(PhTMC). The 2‐bromophenyl derivative showed a T g of 69.5 °C which represents a nominal increase in comparison to the 4‐bromo derivative that we reported earlier. This suggests that the position of the substituent does not have a critical impact on T g . With naphthalene derivatives, the increase in steric bulk led to an increase in T g . Increase of chain length beyond fifty monomer units had a minimal impact on T g . Finally, when 4‐bromonaphthyl moiety was the pendant group, we observed a T g of 97 °C. This demonstrates that T g can be varied significantly by modifying the pendant groups. We have also shown that the 1,3‐diols used in our polymer are non‐cytotoxic.