Studies on the structure and morphology of perylene containing polymers

Incorporating functional small molecules as part of a polymer, either in the main chain or side group, is a strategy to improve the mechanical properties, processing options etc. for device applications. The structure and morphology of such polymers play a vital role in the performance and life-time of the device. This thesis describes the structure and morphological studies on polymers containing perylene. We discuss the crystalline conformations of perylene polyimides (PPIs), with alkyl spacers varying in length from C 3 to C12 in Chapter 3. Several changes in the spectra are seen with an increase in annealing time, at a given temperature. With an increase in annealing time, X-ray diffraction patterns indicate a crystal to mesogenic transition.;We have also designed a new approach to novel perylene-based self-assembled structure. Self-assembly of the perylene segment leads to vesicle formation of perylene end-capped poly(dimethyl siloxane) (perylene end-cap-PDMS) in non-aqueous media. TEM images of the vesicles show either a bilayer or a trilayer structure depending on the solubility parameter of the solvent. This initial attempt to prepare such vesicles in non-aqueous media may be applicable to similar systems.;The polymers described above are notoriously insoluble in most organic solvents. Co-polymerization to disrupt the crystal packing is a common strategy to impart solubility. Chapter 4 describes the work on a series of perylene-containing block copolyimides with different ratios of perylenetetracarboxylic dianhydride and 4, 4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). The copolymers are semi-crystalline up to a concentration of 60% (mol) 6FDA and are " conformational isomorphism" with homopolymer of PPI-12.