Correlation between thermal, optical and morphological properties of heterogeneous blends of poly(3-hexylthiophene) and thermoplastic polyurethane

Abstract

A correlation between thermal, optical and morphological properties of self-sustained films formed from blends of poly(3-hexylthiophene) (P3HT) and thermoplastic polyurethane (TPU), with 1, 10 and 20 wt% of P3HT in TPU, is established. Images of scanning electron microscopy (SEM) show the formation of domains of P3HT into the TPU matrix, characterizing the blend material as heterogeneous. The heat capacity (C(p)) dependence on P3HT contents was investigated in a large temperature interval. In the region of the TPU glass transition, the difference between the experimental and predicted ΔC(p) values is more pronounced for the 1 wt% case, which strongly suggests that in this case there is a higher influence of the P3HT chains on the TPU matrix. The SEM images for the 1 wt% blended film present the formation of the smallest P3HT domains in the TPU matrix. The relatively high reduction of the PL intensity of the pure electronic transition peak in the 1 wt% blended film, in comparison to the other blended films and also to a pure P3HT film, favours the assumption that the smallest P3HT domains are at the origin of a more structural disordered character. This fact is in agreement with the results obtained by Raman spectroscopy and also by photoluminescence resolved by polarization in stretched self-sustained films, showing an ample correlation between morphological, thermal and optical properties of these blended materials. In addition, the thermoplastic properties of the polyurethane configure very good conditions for tensile drawing of P3HT and other conjugated polymer molecules.

Synthesis and characterization of new 3-substituted thiophene copolymers

“…Some authors 23 have obtained PMOT after 24 h of reaction at room temperature, requiring the addition of methanol as a precipitating agent. Other researchers 17 have shown that keeping the reaction temperature between 0-2 °C yields PMOT after 2 h reaction. The procedure described in this paper yielded PMOT after 2 h reaction at room temperature.…”

“…PMOT has been obtained by other groups 17,24 employing the oxidative method with FeCl 3 . Some authors 23 have obtained PMOT after 24 h of reaction at room temperature, requiring the addition of methanol as a precipitating agent.…”

“…12,17,30 Polymers Each monomer (MOT, TE or TM) (0.05 mol L -1 ) was dissolved in chloroform. A suspension of anhydrous FeCl 3 (0.2 mol L -1 ), also in chloroform, was added to the flask with magnetic stirring at room temperature under an inert atmosphere (Scheme 1).…”

“…The search for new technological materials has significantly contributed to the development of new precursors and synthetic methods that generate materials with desirable properties. [7][8][9][10] These materials can be obtained by different polymerization methods, the most common of which employs ferric chloride as an oxidizing agent under an inert atmosphere, [11][12][13][14][15][16][17] with other methods including electrochemistry techniques, such as cyclic voltammetry, 18 chronoamperometry 19,20 and chronopotentiometry. 21 The electronic and optical properties of these polymers can be controlled using monomers that have functional groups incorporated into the structure that can contribute to the properties of the polymer chain; for example, poly(3-methoxythiophene) has been extensively studied due to the presence of oxygen in the alkoxy group, which decreases the oxidation potential of the monomer and polymer through its effects as an electron donor substituent.…”

Oligômeros e polímeros derivados do tiofeno: síntese e aplicações

“…16 A polimerização química mais utilizada emprega haletos metá-licos como agente iniciador, sendo o cloreto férrico o mais utilizado com razão molar 4:1 (FeCl 3 :monômero) sob atmosfera inerte. [98][99][100][101][102][103][104][105] Politiofenos e derivados também podem ser obtidos através do acoplamento de Grignard (tipo Kumada), realizado a partir de monômeros 2,5-di-halogeniotiofeno 47 e derivados como mostrado na Figura 18. 3 Pomerantz e colaboradores 106 obtiveram polímeros derivados de tiofenos (dibromo-ésteres) através da reação de acoplamento de Ullmann, utilizando três equivalentes de cobre metálico em DMF, porém esta reação teve um tempo relativamente alto (7 dias), o que leva à conclusão de que o método oxidativo com FeCl 3 apresenta bons resultados com relação ao tempo de reação (cerca de algumas horas, tendo um máximo reportado de 24 h por alguns autores 107 ).…”