In situ microwave‐assisted polymerization of polyethylene terephtalate in layered double hydroxides

Abstract

The synthesis of poly(ethylene terephthalate) (PET)/layered double hydroxide (LDH) nanocomposites through microwave methods has been investigated. To enhance the compatibility between the PET polymer and the LDH, dodecyl sulfate was intercalated in the lamellar structure. The organo-LDH structure was confirmed by powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). PET nanocomposites were prepared with 0-10 wt % of LDH content by in situ microwave-assisted polymerization. PXRD was used to detect the formation of the exfoliated PET/LDH nanocomposites. Transmission electron microscopy was used to observe the dispersed layers and to confirm the exfoliation process. FTIR spectroscopy confirmed that the polymerization process had occurred. TG and DTA are used to study changes in thermal stability of the nanocomposites, which resulted enhanced by well dispersed LDHs layers.

Manufacture and characterization of nanocomposite materials obtained from incorporation ofd-glucose functionalized MWCNTs into the recycled poly(ethylene terephthalate)

“…The endothermic peak at ~220 °C is ascribed to the melting-transition temperature (T m ). [27,28] The endothermic peak of T m for R-PET is recorded at 270 °C and its value is directly related to the nanofiller loading. [27,28] T m values for NCs of 1, 2, and 4 wt.% were 253, 250, and 243 °C, respectively.…”

One Decade of Microwave‐Assisted Polymerizations: Quo vadis?

“…Rives and coworkers described the preparation of PET/ layered double hydroxide (PET/LDH) nanocomposites by in situ microwave-assisted polymerization in a multi-mode Milestone Ethos Plus microwave reactor. [184] LDH was dispersed in a mixture of PET, ethylene glycol, dimethyl terephthalate, and zinc acetate by sonication for 1 h. This mixture was heated stepwise to 270 8C, and the final temperature was maintained for 35 min. The preparation time could be reduced significantly by the use of microwave-assisted heating.…”

Preparation of poly(ethylene terephthalate)/layered double hydroxide nanocomposites by in-situ polymerization and their thermal property

“…Lee and coworkers [18] prepared PET/LDH nanocomposites using anionic surfactants intercalated LDHs by a direct melt compounding method. Rives and coworkers prepared PET/LDH nanocomposites through a microwave [19] and mechanical grinding method [20]. Dodecylsulfate intercalated LDHs were used to enhance the compatibility between the PET polymer and the LDHs.…”

“…However, in situ polymerization has become the main procedure for the preparation of nanocomposites due to its versatility and compatibility with reactive monomers [22], as well as permitting the control of the polymer and the composite structures. This method relies on the swelling of the organically modified LDHs by the monomer, followed by in situ polymerization initiated thermally or by addition of a suitable compound (catalyst) [19]. The chain growth in the LDH galleries accelerates exfoliation and nanocomposite formation [6].…”

“…Decomposition of PET takes place in three steps [19]. The first weight loss starts at about 300°C, corresponds to removal of water.…”