The use of photoinitiated free-radical cyclopolymerization in the preparation of novel side-chain liquid-crystalline polydienes

The technique of photoinitiated free-radical cyclopolymerization has been used to produce a variety of novel side-chain liquid-crystalline (SCLC) polymers in which an alicyclic ring structure is incorporated into a polymer backbone. Most of the SCLC polymers gave glass transition temperatures (T-g) around room temperature and clearing points around 60-70 degrees C. However, the poly(1,5-hexadiene) was the exception to this, exhibiting a T-g value of 14.5 degrees C and a clearing point of 132.5 degrees C. Confirmation of the structure of the alicyclic ring along the polymer backbone is extremely difficult to obtain, but evidence is given in the paper to support the ring structure.