In this study, the liquid phase and vapor phase procedures for silylating cellulose microfibers by hexamethyldisilazane (HMDS) were compared in terms of efficiency. The influence of functionalization degree on the morphology of microfibers and their interaction with polydimethylsiloxane (PDMS) matrix has been investigated. The antibacterial properties of silylated cellulose microfibers hybridized with Ag nanoparticles, obtained by in situ chemical reduction, were also studied. Sample morphology investigations were carried out using spectroscopy and microscopy techniques (FTIR, XPS, TEM, SEM, EDS, XPS). Trimethylsilyl moieties appear on the surface of the cellulose microfibers after modification and improve the dispersibility of the microfibers, allowing strong interaction with the PDMS matrix and favoring its crosslinking density. Microfibers functionalized by the vapor phase of HMDS show smoother surfaces with higher concentrations of Si-containing groups, resulting in a more hydrophobic wetting behavior and a greater influence on the mechanical properties of the polymer. The silylated cellulose microfiber–Ag nanohybrid shows stronger antimicrobial activity towards Gram-positive and Gram-negative bacteria strains compared to that of the untreated hybrid. A PDMS composite loaded with this hybrid exhibits the ability to inhibit bacterial growth.

The adhesion properties of polychloroprene can be improved by addition of such materials as piperylene–styrene co-polymer (PSC), VeoVa-10 polymer, VeoVa-11/methyl methacrylate/2ethylhexyl acrylate co-polymer (VeoVa-11/MMA/2EHA) and poly(vinyl acetate) waste (wPVAc). Here, the relationship between adhesion properties and surface tension of polychloroprene was investigated. Contact angle measurements have been used to study the effects of nature and content of polymeric additives on the adhesion and surface properties of polychloroprene. Low-surface-tension VeoVa-10 polymer has the tendency to migrate to the surface of polychloroprene; thus, adhesion is determined mainly by this additive property. Enrichment of polychloroprene film bottom layer by the additive was observed using high-surface-tension PSC and wPVAc. In this case, the adhesion properties of polychloroprene depend on the interactions at the interface. Adhesion properties of polychloroprene were found to depend not only on compatibility between adhesive components, but also on compatibility between the adherend and the adhesive.

The most effective means to protect against bacterial invasion and to reduce the risk of healthcare-associated infections are antibacterial components synthesis. In this study, a novel process for the synthesis of organic–inorganic hybrid coatings containing silver nanoparticles is presented. Silver nanoparticles and polymer formation proceeds simultaneously through the in situ photoreduction of silver salt to silver nanoparticles and UV-crosslinking of bifunctional aliphatic silicone acrylate. The nanocomposite films with 0.5–1.43 wt % of silver nanoparticles concentration were obtained and investigated. The formation of silver nanoparticles in polymer matrix was confirmed via UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, scanning electron spectroscopy, and energy dispersive spectroscopy. Our investigations clearly show the formation of silver nanoparticles in silicone acrylate network. Direct photoreduction of silver salt by UV-radiation in the organic media produced silver nanoparticles exhibiting cubic crystal structure. The size of nanoparticles was determined to be near 20 ± 5 nm. The antibacterial activities of coatings were determined using the disc diffusion and direct contact methods. UV-curable silicone acrylate hybrid coatings exhibited antibacterial activity against harmful bacteria strains.

The effect of piperylene-styrene copolymer (PSC) content on the bulk and surface properties of polychloroprene (CR) adhesive was investigated by different methods. Addition of PSC improves adhesion and strength properties of CR. PSC slightly deteriorates thermal stability of CR. X-ray diffraction, UV, and IR spectroscopies studies showed that no chemical interaction between CR and PSC phases occurs. Distinct bulk and surface structure of modified adhesive is caused by the high surface energy difference between CR and PSC phases. By AFM force-distance curve measurements it was deduced that the differences between pull-off force values of modified CR film surfaces in contact with air and backing was related to the enrichment of the higher surface energy component at the backing/film interface. The properties and structure of boundary layers of adhesive modified by high surface energy polymeric additive are essential for the adhesion behavior.

In this study the miscibility of polyvinyl chloride (PVC) and poly-e-caprolactone based thermoplastic polyurethanes (TPU) waste blends were investigated by dilute solution viscometry. The miscibility criteria a, Db, DB, and D[h] were used to assess the degree of miscibility of polymers in tetrahydrofuran solution. Also, to assess the miscibility and microstructure of PVC/TPU blends obtained by solution casting have been characterized by X-ray diffraction. The tensile strength and deformability properties varying on the blend composition were determined. It was found that PVC and TPU are partially miscible, their blend is amorphous and show two-phase structure. TPU changes the mechanical behaviour of PVC the blends. Increase of TPU content causes PVC elongation at break increase and tensile strength decreases. DOI: http://dx.doi.org/10.5755/j01.ms.19.4.3145