Nonlinear optical polymers. 1. Novel network polyurethane with azobenzene dye in the main frame

Abstract

Novel nonlinear optical (NLO) network polyurethane of lysine triisocyanate (LTI) with 44N-(2-hydroxyethyl)-N-methylaminol-3'-(hydroxymethyl)azobenzene (AZODIOL) dye as a NLO-phore has been prepared for second harmonic generation (SHG). A soluble prepolymer of LTI with AZODIOL was prepared, and then a thin prepolymer film was spun-cast on an indium tin oxide coated glass substrate. Two types of poling were carried out. One-step poling process: while high voltage between 5.0 and 8.0 kV was applied to the corona wire, the sample film was heated up and held at a temperature range of 70-190 "C for 10 min and then cooled down to room temperature for 40 min. Two-step poling process: while high voltage was applied to the corona wire, the sample was heated up and held at 90 "C for 1 h and then heated up again and held at a temperature range of 90-190 "C for 30 min. Then the sample was cooled down to room temperature while applying the poling field. The effects of the above poling condition and storage time and thermal annealing on SHG activity are investigated in connection with polymer structure. Better long-term thermal stability of SHG at room temperature can be obtained for the sample prepared by a two-step poling process. This better thermal stability is interpreted to be due to the smaller free volume for that sample.

Injectable Biodegradable Polyurethane Scaffolds with Release of Platelet-derived Growth Factor for Tissue Repair and Regeneration

“…Furthermore, it was of interest to compare the biocompatibility and degradation of PUR scaffolds synthesized from aliphatic and lysinederived triisocyanates. While LTI and HDIt have been used to synthesize cast elastomers with improved properties, such as optical clarity and thermal stability (42), their use in biodegradable PUR scaffolds has not been previously reported. The effects of triisocyanate composition on biocompatibility, biodegradation, and mechanical properties were investigated, as well as the potential of the PUR scaffolds for release of growth factors.…”

Novel poly(aryl ether ketone) with electro-optic chromophore side chains for light modulators

“…In theory, the chromophore in polymer P2 has a larger inter-sertial volume, and polymer P2 should have worse long-term stability [43,55]. However, Fig.…”

Preparation and characterization of all organic NLO sol-gel materials based on amino azobenzene dyes

“…Tab. 6 shows the s and b values for the benzoguanamine-based NLO polymers at various temperatures (25,50,75, and 100 8C).…”