Preparation of fluorinated methacrylate/clay nanocomposite via in‐situ polymerization: Characterization, structure, and properties

Abstract

Novel fluorinated coating containing well-dispersed silicate nanolayers is successfully produced via in-situ free radical polymerization of 2,2,2-trifluoroethyl methacrylate in the presence of vinylbenzyl-functionalized montmorillonite with different loading. The organic modification of sodium montmorillonite is achieved through an ion exchange reaction with triphenylvinylbenzylphosphonium chloride as surfactant prepared before use by reaction with vinylbenyl chloride and phosphine. The following in-situ polymerization in the presence of organomodified clay leads to fluorinated nanocomposites with of partially exfoliated and intercalated morphologies, as determined via XRD and TEM analysis. The nanoscale dispersion of clay layers is also evidenced by thermal analysis; a moderate decrease of the glass transition temperature about 2-8 8C compared to their virgin PMATRIF and an improvement of their thermal stability as evidenced by TGA. The wettability of the nanocomposite films is also studied by contact angle measurements with water. The incorporation of organomodified clays not only increases the hydrophobicity of the fluorinated polymers but also improves the surface properties of obtained nanocomposites. Compared the virgin homopolymer, the mechanical properties of the nanocomposites are reduced by addition of organomodifed clay at temperature from 30 to 60 8C, whereas this trend is gradually decreased at higher temperature.

Effect of clay on the dielectric properties of novel fluorinated methacrylate nanocomposites

“…With this assumption and the calculated VFT parameters for PMATRIF, T g is determined to be about 80°C. This value is in excellent agreement with the previously measured T g values .…”

“…This is can be attributed to the creation of a dense polymer package which is the result of the filler loading increase that affect the free volume and hence rise the chain mobility of polymer. A decrease in T g with increasing MMT content has also been reported in previous works of Karamane et al basing on thermal study and was found that the temperature of the vitreous transition of nanocomposites decreased with the incorporation of MMT. This can be explained by the fact that the addition of MMT layers reduces the molecular weight of obtained PMATRIF.…”

“…Indeed, unlike aromatic polyesters and polycarbonates in which dipolar groups are rigidly attached to the main‐chain, the PMATRIF have an added dipole‐component in the ester side‐groups flexibly attached to the main chain. In the range of 82°C, an additional relaxation process is observed and attributed to α relaxation, associated to the motions of the main polymer chains occurring at and above glass transition temperature ( T g ) . As seen, when the temperature increases, the maximum of the two loss relaxation peaks are shifted to higher frequencies, due to an improvement of dipolar mobility leading to a decrease in the relaxation times .…”

“…The preparation of PMATRIF/VBz‐MMT nanocomposites with different loading of organomodified clay, and detailed structural characterizations were described according to a previously published report . The organophilic clay VBz‐MMT (1, 3, and 5% of the monomer by weight) and the monomer (7 g, MATRIF) was combined in reactor and sonicated for 45 min in an Ultrasonic bath.…”

“…In order to achieve a good dispersion of MMT in polymer matrix, MMT can be for example organomodified through an ion exchange reaction with triphenylvinylbenzylphosphonium chloride. Previously, we have reported the synthesis and characterization of a novel series of fluoropolymer/clay nanocomposites based on MATRIF using different wt% of MMT by in situ polymerization . As part of our continuous interest to develop new methodologies for clay/polymer/clay nanocomposites and investigate their structure–properties relationship, we herein report the effects of MMT content on the molecular dynamics and polarization of the MMT/PMATRIF nanocomposites investigated by dielectric relaxation spectroscopy (DRS) analysis.…”