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Polyethylene-, polyvinylidene chloride-, and per- and polyfluoroalkyl substance-coated paper generate microplastics or fluorochemicals in the environment. Here, we report an approach for the development of oil-resistant papers using an environmentally friendly, fluorine-free, water-dispersible poly(dimethylsiloxane) (PDMS) coating on kraft paper. Carboxylic-functionalized PDMS (PDMS-COOH) was synthesized and subsequently neutralized with ammonium bicarbonate to obtain a waterborne emulsion, which was then coated onto kraft paper. The water resistance of the coated paper was determined via Cobb60 measurements. The Cobb60 value was reduced to 2.70 ± 0.14 g/m2 as compared to 87.6 ± 5.1 g/m2 for uncoated paper, suggesting a remarkable improvement in water resistance. Similarly, oil resistance was found to be 12/12 on the kit test scale versus 0/12 for uncoated paper. In addition, the coated paper retained 70–90% of its inherent mechanical properties, and more importantly, the coated paper was recycled via pulp recovery using a standard protocol with a 91.1% yield. [ABSTRACT FROM AUTHOR]

Reported herein is the fabrication of antimicrobial polypropylene (PP) surfaces with nonleachable magnesium hydroxide biocides and compares its performance with leachable copper (II) chloride dihydrate. Two methods were used for creating PP‐bearing biocides. One way involves melt‐blending of biocides and PP and subsequent injection molding to create the desired antimicrobial PP surface. Another technique consists of thermal embossing of antimicrobial agents on the PP surface. The biocide‐bearing PP surfaces were evaluated against Escherichia coli (E. coli) K‐12 MG1655) for up to 24 h. In the case of injection‐molded PP system, leachable CuCl2·2H2O showed a 5.87 ± 0.01 log reduction after 24 h, but only 0.47 ± 0.03 log reduction for PP bearing nonleachable Mg(OH)2. On the contrary, thermally embossed PP with CuCl2·2H2O and Mg(OH)2 showed 2.28 ± 0.03 and 3.78 ± 0.03 log reductions, respectively, after 24 h. The nonleachable Mg(OH)2 imparted antimicrobial properties only to the PP surface prepared via thermal embossing. In contrast, owning to the leachable copper ions, leachable CuCl2·2H2O biocides imparted PP surfaces antimicrobial irrespective of the molding or surface embossing approach. This approach provides an advantage for nonleachable PP‐based antimicrobial surfaces in overcoming the toxicity concern associated with plastics bearing leachable biocides. [ABSTRACT FROM AUTHOR]

Chemical recycling enables plastics to be a part of the circular economy as it can cope with contaminated as well as mixed plastics waste. Herein, two important discoveries are reported. One innovation is the use of table salt (NaCl) to facilitate the low temperature pyrolysis of polyolefins comprised of high‐density polyethylene (HDPE), low‐density polyethylene (LDPE), linear low‐density polyethylene (LLDPE), and polypropylene (PP) at the ratio of (4:2:2:3), respectively, thus enabling the efficient recycling of these mixed plastics. For comparative analysis, two different Pt catalysts as well as a control are investigated. Compared to the control, the use of table salt at 10 wt.% increased both the oil and gas contents by 80% and enabled 100% conversion to gas and oil without producing any undesirable wax. The second innovation is that metallized plastics are successfully pyrolyzed with table salt with excellent conversion efficiencies. The obtained oil fraction is further characterized using gas chromatography‐mass spectrometry (GC‐MS). In addition, the re‐use of salt, the effect of salt particle size and effect of the wt.% are explored. The thermal properties of the wax (solid) are characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Economic estimation revealed a 3.5‐fold increase in revenue can be generated by the novel method as compared to pyrolysis without any salt. In contrast, pyrolysis with a conventional Pt/alumina system incurs huge losses. These findings suggest that table salt can offer a transformative approach toward an inexpensive (4 cents per kg) and efficient pyrolysis methodology for the conversion of mixed plastics waste to useful hydrocarbon products. [ABSTRACT FROM AUTHOR]