The Preparation And Properties Of Poly(3-hexylthiophene) / Poly(oxyethylene) Blend Films

Poly(3-hexylthiophene)(P3HT) is a type of polymers with great application potential in flexible electronics field due to its good optical and electrical properties, chemical stability and processing performance. In this dissertation, P3 HT was synthesized using the Grignard metathesis(GRIM) method. The P3 HT was then mixed with high molecular weight poly(oxyethylene)(PEO) and the obtained blends were prepared into films by solution casting and electrospinning, respectively. The multi-walled carbon nanotubes(MWCNTs) were also added into the P3HT/PEO blends using non-covalent method before the P3HT/PEO/MWCNTs blend films were prepared. The crystallization behaviors, conductivity and mechanical properties of these films were studied. The obtained main results are as follows:1. The data of 1H-NMR, FTIR, UV-vis and fluorescence spectra confirmed the chemical structure and high regioregularity degree of the synthesized P3 HT. The GPC result indicated that the P3 HT had high molecular weight and narrow molecular weight distribution.2. PEO could improve the spinnability of P3 HT solution. And the morphologies of P3HT/PEO electrospun fibers could be adjusted with the processing parameters such as solution concentration and operation voltage. In addition, oriented electrospun fibers could be collected with the roller.3. Blending didn't change P3 HT or PEO crystal structure while P3 HT inhibited the crystallization of PEO which resulted in the decrease of melting point and crystallinity degree of PEO. Moreover, the melting temperatures of polymers in P3HT/PEO electrospun films were lower than those in their casting films. On the other hand, the conductivity, elastic modulus and tensile strength of the P3HT/PEO casting films increased with P3 HT content increasing. And the casting films had higher properties as mentioned above than the electrospun films.4. The TEM results photos indicated that the surface of MWCNTs was coated with a uniform P3 HT layer and the morphology of MWCNTs was not obviously damaged when MWCNTs were added into P3HT/PEO blends. However, the MWCNTs brought the liquid jet with flow instability during electrospinning so that spinnability of the blends got worse after the MWCNTs content was more than 10%. MWCNTs could increase the melting point and crystallinity degree of PEO because of their heterogenous nucleation in P3HT/PEO blends. The conductivity, elastic modulus and tensile strength of P3HT/PEO/MWCNTs casting films were improved by increasing MWCNTs content. Similarly, these properties of the P3HT/PEO/MWCNTs casting films were higher than those of the electrospun films.