Crystallization-Controlled Structure and Thermal Properties of Biobased Poly(Ethylene2,5-Furandicarboxylate).

Crystallization-controlled structure and thermal properties of biobased poly(ethylene 2,5-furandicarboxylate) (PEF) were studied. The cold-crystallization temperature controlled the structure and thermal properties of the biobased PEF. The melting was complex and evidenced the presence of a significant fraction of less-stable crystals with a low melting temperature that linearly increased with , which formed already during the early stages of crystallization, together with those melting at a higher temperature.

Structure and Mechanical Properties of iPP-Based Nanocomposites Crystallized under High Pressure.

The unique nonparallel chain arrangement in the orthorhombic γ-form lamellae of isotactic polypropylene (iPP) results in the enhancement of the mechanical properties of γ-iPP. Our study aimed at the investigation of the mechanical properties of γ-iPP nanocomposites with 1-5 wt.% multiwall carbon nanotubes (MWCNT) and 5 wt.

Electrical Conductivity and Antibacterial Activity of Woven Fabrics through Quercetin-Assisted Thermal Reduction of a Graphene Oxide Coating.

Cotton and poly(ethylene terephthalate) (PET) woven fabrics were coated with graphene oxide (GO) using a padding method and the GO deposited on the fiber surfaces was thermally reduced to impart electrical conductivity to the fabrics. To assist the thermal reduction of GO, quercetin (Q)-a natural flavonoid-was used. To this end, before the reduction, the GO-padded fabrics were immersed in Q solutions in ethanol with different Q concentrations.

Cytotoxicity studies and antibacterial modification of poly(ethylene 2,5-furandicarboxylate) nonwoven.

Novel poly(ethylene 2,5-furandicarboxylate) PEF nonwovens were produced by solution electrospinning and further modification. To improve the wettability of the hydrophobic nonwovens with water, they were treated with sodium hydroxide. Cytotoxicity tests carried out with human keratinocytes confirmed that the nonwovens did not have a toxic effect on healthy cells.

Electrically conductive crystalline polylactide nonwovens obtained by electrospinning and modification with multiwall carbon nanotubes.

Polylactide nonwovens were electrospun from solutions and then crystallized, one in α-form, and another, S-PLA, made of poly(l-lactide) and poly(d-lactide) 1:1 blend, in scPLA crystals with high melting temperature, close to 220 °C. To make the nonwovens electrically conductive, they were coated with multiwall carbon nanotubes (MWCNT) by padding and dip-coating with an aqueous dispersion of MWCNT. The electrical conductivity evidenced the formation of the electrically conductive MWCNT network on the fiber surfaces.

Formation of UHMWPE Nanofibers during Solid-State Deformation.

A network of nanofibers is formed in situ through solid-state deformation of disentangled ultra-high molecular weight polyethylene (dis-UHMWPE) during compounding with a polyolefin elastomer below the melting temperature of dis-UHMWPE crystals. Dis-UHMWPE was prepared in the form of powder particles larger than 50 μm by polymerization at low temperatures, which favored the crystallization and prevention of macromolecules from entangling. Shearing the blend for different durations and at different temperatures affects the extent to which the grains of dis-UHMWPE powder deform into nanofibers.

Microbiologically Pure Cotton Fabrics Treated with Tetrabutylammonium OXONE as Mild Disinfection Agent.

The microbiological purity of textiles plays a pivotal role in the use of textiles, especially in hospitals and other medical facilities. Microbiological purity of cotton fabric was achieved by a new disinfection method using tetrabutyloammonium OXONE (TBA-OXONE) before washing. As a result of the disinfection, the cotton fabric became microbiologically pure, despite the markedly decreased washing time with respect to the widely used standard procedure.

Antibacterial Electroconductive Composite Coating of Cotton Fabric.

Graphene oxide (GO) was deposited on a cotton fabric and then thermally reduced to reduced graphene oxide (rGO) with the assistance of L-ascorbic acid. The GO reduction imparted electrical conductivity to the fabric and allowed for electrochemical deposition of Ag° particles using cyclic voltammetry. Only the Ag°/rGO composite coating imparted antibacterial properties to the fabric against and .

Crystallization of Isotactic Polypropylene Nanocomposites with Fibrillated Poly(tetrafluoroethylene) under Elevated Pressure.

Nanocomposites of isotactic polypropylene with 1-5 wt.% of fibrillated PTFE (PP/T) were prepared, and their crystallization during cooling under elevated pressure, in a wide pressure range, up to 300 MPa, as well as the resulting structure, were examined. The crystallization peak temperatures of PP/T, especially with 3 and 5 wt.

Phase Structure and Properties of Ternary Polylactide/Poly(methyl methacrylate)/Polysilsesquioxane Blends.

Ternary blends of polylactide (PLA, 90 wt.%) and poly(methyl methacrylate) (PMMA, 10 wt.%) with functionalized polysilsesquioxanes (LPSQ-R) were obtained by solution blending.

Modification of Polylactide Nonwovens with Carbon Nanotubes and Ladder Poly(silsesquioxane).

Electrospun nonwovens of poly(L-lactide) (PLLA) modified with multiwall carbon nanotubes (MWCNT) and linear ladder-like poly(silsesquioxane) with methoxycarbonyl side groups (LPSQ-COOMe) were obtained. MWCNT and LPSQ-COOMe were added to the polymer solution before the electrospinning. In addition, nonwovens of PLLA grafted to modified MWCNT were electrospun.

High-Pressure Crystallization of iPP Nucleated with 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol.

1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol (DMDBS) is highly effective in nucleation of the α- form of isotactic polypropylene (iPP). However, its role in high-pressure crystallization of iPP, facilitating the formation of the γ- polymorph, has not been explored. The present paper focuses on the influence of DMDBS on nucleation of high-pressure crystallization of iPP.

PLA/β-CD-based fibres loaded with quercetin as potential antibacterial dressing materials.

Microbial infections lead to elevated inflammatory responses, which usually result in prolonged and incomplete wound healing. Therefore, there is an increasing demand for biodegradable fibres that are effective against a different range of microorganisms, especially those with antibiotic resistance. Herein, quercetin-(Q)-loaded polylactide-based fibres were developed using the electrospinning technique.

Melatonin significantly influences seed germination and seedling growth of Bertoni.

Background: Melatonin (MEL) is a signaling molecule in plants that affects developmental processes during vegetative and reproductive growth. Investigations have proved that exogenously applied MEL also has the potential to improve seed germination and plant development.

Methods: In the present study, seeds of stevia, a species with a very low germination rate, were germinated on an agar gel (AG) containing MEL at various concentrations (5, 20, 100, and 500 µM) in light.

The role of nucleating agents in high-pressure-induced gamma crystallization in isotactic polypropylene.

Nucleation of the γ-form in isotactic polypropylene (PP) under high pressure was investigated. Three nucleating agents were used to nucleate crystallization of PP under atmospheric pressure: commercial Hyperform HPN-20E from Milliken Chemical, poly(tetrafluoroethylene) particles nucleating the α-form, and calcium pimelate nucleating the β-form. Crystallization of neat PP and PP with addition of 0.

Novel blends of polylactide with ethylene glycol derivatives of POSS.

Polylactide (PLA), a main biodegradable and biobased candidate for the replacement of petrochemical polymers, is stiff and brittle at room conditions. It is therefore of high interest to formulate new PLA-based materials suitable for applications demanding flexibility and toughness. In this work, novel blends of PLA with polyhedral oligomeric silsesquioxanes (POSS) grafted with longer (P1) and shorter (P2) arms of ethylene glycol derivatives were prepared and studied.

High-pressure crystallization of isotactic polypropylene droplets.

Dispersions of isotactic polypropylene (PP) particles in polystyrene (PS) were produced by interfacially driven breakup of nanolayers in multilayered systems that were fabricated by means of layer-multiplying coextrusion. The droplet size was controlled by the individual PP layer thickness ranging from 12 to 200 nm. In addition, PP was melt blended with PS to produce PP droplets larger than those formed by breakup of nanolayers.

Mechanical and thermal properties of green polylactide composites with natural fillers.

Green composites of PLA with micropowders derived from agricultural by-products such as oat husks, cocoa shells, and apple solids that remain after pressing have been prepared by melt mixing. The thermal and mechanical properties of the composites, including the effect of matrix crystallization and plasticization with poly(propylene glycol), have been studied. All fillers nucleated PLA crystallization and decreased the cold-crystallization temperature.