Synthesis and characterization of telechelic PCL homo and PCL-PSt-PCL block type macrophotoinitiators

In this thesis, synthesis and characterization of telechelic poly(ɛ−caprolactone) (B-PCL-B) homo and poly(ɛ-caprolactone)-polystyrene-poly(ɛ−caprolactone) (B-PCL-PSt-PCL-B) block type macrophotoinitiators were performed. For this purpose first, well-defined PCL macrophotoinitiator with benzoin photoactive group (B) at one end of the chain (B-PCL) was synthesized via ring-opening polymerization (ROP) of ɛ−caprolactone monomer in the presence of benzoin initiator and Sn(Oct)2 catalyst. The synthesized B-PCL macrophotoinitiator was reacted with 4,4′-azobis(4-cyanovaleric acid) (ACVA) to form a polymer with an azo group (-N=N-) in the middle of the chain and benzoin photoactive groups (B) at both ends of the chain (telechelic macro-azo PCL photoinitiator, B-PCL-PSt-PCL-B). Then, telechelic B-PCL-PSt-PCL-B block type macrophotoinitiator was synthesized via thermal free radical polymerization using telechelic B-PCL-B macrophotoinitiator as the macroinitiator and styrene as the monomer. Characterization of the macrophotoinitiators was performed by FT-infrared, 1H-NMR, 13C-NMR, GPC, UV-Vis and fluorescence techniques. In addition, the synthesized B-PCL-PSt-PCL-B macrophotoinitiator was used as a prepolymer in the photoinduced free radical promoted cationik polimerization of cyclohexene oxide (CHO) monomer to prepare a five-block copolymer as PCHO-PCL-PSt-PCL-PCHO (ABCBA type copolymer). The characterization of the synthesized five-block copolymer was done by FT-infrared, 1H-NMR and GPC techniques.