RESULTS | pipatt

Scientific reports

Stage 2017

Stage 2015

Stage 2016

Obtained results in Stage 2

- The properties of studied polyimides in solution are affected by their chemical structure and implicitly by their conformation

- The refractive index and dielectric constant are changed by variation of free volume and polyimide chain polarizability. This also allows to achieve good transparency in visible domain, recommending the samples for alignment layer purposes.

- Biocompatibility with blood of prepared polymer films was proved by their surface physico-chemical properties, confirming cohesion interactions at polymer/blood interface.

- Surface structuring of the new polymer films was successful by all employed methods, leading to films with surface pattern of dimensions controllable through experimental parameters.

Obtained results in Stage 1

- It was performed scientific documentation concerning polyimides and their structural modification in order to obtain partially aliphatic polymers with enhanced solubility, as stated in the proposed objective.

- Two types of structures were synthesized: polyimides and copolyimdes with partially aliphatic structure given by the used dianydride along with other monomers that are alicyclic or aromatic.

- The obtained polymers are soluble in polar solvents (NMP, DMAc, DMF): the increase in solubility is due to enhanced flexibility of macromolecular chain sequences induced by the presence of alicyclic units and linking groups with greater freedom of movement (-O-, -SO2-, -C(CF3)2) that decrease internal rotation entropy. Most synthesized polymers form dimensionally stable films that are flexible and transparent.

Obtained results in Stage 3

- liquid crystal interactions with different polyimide structures were determined

- structuring conditions impact on LC alignment was evaluated

- biomedical aspects of polyimide films before and after surface modification were investigated