Formation of Poly(propylene)‐Based Biocomposite Films and Their Use in the Attachment of Methylene Blue

Abstract

Biocomposite PP‐g‐PAAc‐CS films based on PP were generated and utilized as support of methylene blue, a thiazidic dye. Using a photograft polymerization of acrylic acid, the PP film was functionalized with carboxyl groups (PP‐g‐PAAc), which attached chitosan by electrostatic bond. A longer poly(acrylic acid) chain or a higher CS immobilization temperature led to a higher chain interpenetration and crosslinking reaction. Immobilized MB confirmed to possess redox activity from its reaction with ascorbic acid, where the dye decomposition rate ($R'_{\rm d} $) increases together with the chain interpenetration, then decreasing with the increase in the crosslinking degree.magnified image

Original antifouling strategy: Polypropylene films modified with chitosan‐coated silver nanoparticles

“…On the other hand, the surface morphology of AgNP/CS‐coated PP films was characterized by SEM. Figure (A) and Supporting Information Figure S.2‐left/up show that the surface of AgNP 30 /CS‐coated PP film has the formation of CS granules that are organized by forming cords, a typical arrangement pattern already described by Cavallo et al . The comparison of the surface topography for both AgNP/CS‐coated PP films determined from secondary electrons shows no significant differences between them [Figure (A) and Supporting Information Figure S.2‐left/up].…”

“…In the second step, BP* abstracts a hydrogen atom from the PP backbone, generating a new active radical (BPH). Finally, the substituent BPH was displaced and the addition of AA monomer onto PP backbones took place . During this reaction, a fraction of the monomers was involved in the AA‐photograft polymerization onto the PP chains, while the rest of monomers produced free PAA backbones by homopolymerization in the bulk or no reacted.…”

“…After 60 s, the G value slightly changes, since almost all the monomer has already been consumed in the RM. In addition, a prolonged exposure time leads to the degradation of the surface PP chains, which results in low‐molecular‐weight oxides . The initiation of AA homopolymerization is favored by these oxides, and competes with photograft polymerization.…”

“…Additionally, the AgNP content in the film was determined by a potentiometric assay, which was nearly 0.02 and 0.08 wt % for AgNP 5 /CS and AgNP 30 /CS, respectively. Subsequently, AgNP/CS complexes were adsorbed on PAA‐grafted PP films containing different G values, driven by the electrostatic interaction between the PAA carboxyl and CS amino groups . The immobilization degree value (I) was calculated with eq.…”

“…Successively, the AgNP/CS complex was adsorbed onto PAA‐grafted PP from electrostatic interactions (Scheme , step 2). The adsorption of the AgNP x /CS complex onto PAA‐grafted PP films with different G values took place under light protection for 15 h at 25 °C using a similar procedure described by Cavallo et al . In all the cases, the adsorption process took place once 1.20 mL of AgNP x /CS complex colloidal suspension was left in contact with the modified face of PAA‐grafted PP film (60 cm 2 ) to obtain a AgNP x /CS‐coated PP film.…”