Photoactive polyurethanes based on 2,2 `-dihydroxy... - BV FAPESP
Advanced search
Start date
Betweenand
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Photoactive polyurethanes based on 2,2 `-dihydroxyazobenzene fluorescent segments

Full text
Author(s):
Paiva, Germana M. S. [1] ; Duarte, Luis G. T. A. [1] ; Faleiros, Marcelo M. [1] ; Atvars, Teresa D. Z. [1] ; Felisberti, Maria Isabel [1]
Total Authors: 5
Affiliation:
[1] Univ Estadual Campinas, Inst Chem, POB 6154, BR-13084971 Campinas, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: JOURNAL OF MOLECULAR LIQUIDS; v. 337, SEP 1 2021.
Web of Science Citations: 0
Abstract

This article presents the synthesis and structural, thermal and dynamic mechanical characterization of segmented polyurethane - PCLDHAB - based on poly(caprolactone)-diol (PCL-diol) as a flexible segment, and polyurethane-diol (PU-diol) as a rigid segment based on 2,2'-dihydroxyazobenzene (2,2'-DHAB). While the precursors PU-diol and PCL-diol are rigid and waxy materials, respectively, PCLDHAB is a flexible, semi-crystalline polymer, which has a heterogeneous amorphous phase. To better understand the absorption spectra of the polyurethanes, theoretical predictions by DFT and TD-DFT of a model molecule in DMF (implicitly added) were carried out. The model molecule was a fragment of the hard segment of the polyurethane's chain, containing one 2,2'-DHAB and two 4'-isocyanate-4'-methylbenzene fragments, bonded to each other by carbamate bonds, the 4-isocyanate-4'-metylbenzene-alt-2,2'-dihydroxyazoben zene. Similar to 2,2'-DHAB, PU-diol and PCLDHAB do not show photoisomerization, however they emit fluorescence. 2,2'-DHAB segments in the polyurethane chains present different conformations with distinct spectroscopic characteristics. However, the conformer's proportion in the polymer chains differs from the 2,2'-DHAB monomers in DMF solution. 2,2'-DHAB emits in two ranges in the UV-vis spectrum while its polyurethanes emit in three ranges, covering a broader wavelength range from ultraviolet to visible. (C) 2021 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 15/25406-5 - Organizing matter: colloids formed by association of surfactants, polymers and nanoparticles
Grantee:Watson Loh
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 13/16245-2 - Photophysical properties of thin films of conjugated polymers
Grantee:Teresa Dib Zambon Atvars
Support Opportunities: Regular Research Grants
FAPESP's process: 15/08541-6 - Nuclear magnetic resonance spectroscopy: beyond molecular structure assignment
Grantee:Claudio Francisco Tormena
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 16/11197-8 - Polyurethanes tri- and tetra blocks functionalized with azo group: synthesis, characterization and evaluation of potential as photo-responsive materials
Grantee:Germana Maria Santos Paiva
Support Opportunities: Scholarships in Brazil - Doctorate