Synthesis of Water-Dispersible Poly(dimethylsiloxane) and Its Potential Application in the Paper Coating Industry as an Alternative for PFAS-Coated Paper and Single-Use Plastics.

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.

Evaluation of antibacterial and anticancer properties of poly(3-hydroxybutyrate) functionalized with different amino compounds.

The chemical modification of biodegradable poly(3-hydroxybutyrate) (PHB) is useful for biomedical applications. In this study, the transesterification reaction of PHB was carried out under reflux conditions in the presence of 1,4-butanediol to form telechelic PHB-diol. Further modification of PHB-diol into PHB-diacrylate was carried out by the reaction of PHB-diol with acryloyl chloride. PHB-diacrylate was grafted with amino compounds such as 1,4-butanediamine, 1,3-propanediamine, 1,2-ethylenediamine, piperazine, cyclohexylamine, 2,2'-(ethane-1,2-diylbis(oxy)) diethanamine (jeffamine EDR 148) and morpholine via Michael-type addition reaction. The functionalized amino-PHB polymers were characterized by using FTIR and 1H NMR techniques. XRD showed that amino-PHB polymers have different crystallinity compared with neat PHB. Some biological activities of amino-PHB polymers were determined such as antibacterial, antioxidant and anticancer activities. In this regard, the results showed that PHB-ethylenediamine revealed a potent antibacterial activity against Staphlococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. All amino-PHB polymers under the study showed reasonable antioxidant activity. Among these polymers, PHB-piperazine showed a potent anticancer effect against in vivo Ehrlich ascetic carcinoma bearing mice.