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ABSTRACT: The aim of this study was to demonstrate mechanical recycling of low density polyethylene (LDPE) films coated with a thin layer of cellulose nanofibrils (CNFs). CNF acts as an effective barrier against oxygen and mineral oil residues. Two different CNF grades were tested, and both were applied onto plasma activated LDPE film using a pilot coating line. The coated films were shredded with the help of liquid nitrogen, compacted and compounded with virgin LDPE and compatibilizer, and processed into cast films and injection molded test specimens. The CNF coatings were completely blent as microscale agglomerates in the LDPE matrix. The effect of these agglomerates on the barrier and heat sealing properties was statistically insignificant compared to recycled uncoated LDPE. The mechanical properties were only moderately changed. CNF‐coated LDPE films can therefore be recycled back into films without sacrificing the characteristic properties of the base polymer. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46237. [ABSTRACT FROM AUTHOR]

Here, the authors report on the preparation of core-shell carbon-ceramic fibrous as well as ceramic tubular catalyst supports utilizing electrospinning and atomic layer deposition (ALD). In this paper, ALD of Ti-Nb-O thin films using TiCl4, Nb(OEt)5, and H2O as precursors is demonstrated. According to the time-of-flight-elastic recoil detection analysis and Rutherford backscattering spectrometry, carbon and hydrogen impurities were relatively low, but depend on the pulsing ratio of the precursors. Optimized ALD process was used for coating of sacrificial electrospun polyvinyl alcohol (PVA) template fibers to yield tubular Ti-Nb-O structures after thermal or solution based PVA removal. Another approach utilized 200-400 nm thick carbon fibers prepared by electrospinning from polyacrylonitrile and subsequent thermal treatment. [ABSTRACT FROM AUTHOR]

ABSTRACT The aim of this study was to evaluate a thin, TEMPO-oxidized (2,2,6,6-tetramethylpiperidine-1-oxyl-mediated oxidation) cellulose nanofibril (CNF) coating as a barrier layer in multilayer packaging films together with biobased polyethylenes. The purpose was also to explore the possible interactions between food products and the biobased films, and to evaluate the feasibility of these films for packaging of dry foods. CNF provided the biobased multilayer films with an oxygen barrier suitable for both demanding food products and modified atmosphere packaging (MAP). The MAP pouches made of these multilayer films retained their atmosphere and shape and protected ground hazelnuts from further oxidation for the storage time used in this study. However, irradiation used to sterilize packed foods and aroma compounds from clove in particular impaired the oxygen barrier property of the CNF layer, while the water vapor barrier property of the multilayer films remained unaffected. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44830. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the feasibility of using highly filled powders as electrostatically applied paper coatings. Powders prepared by two different methods were suitable for electrostatic deposition and they attached to the paper surface with a grounded backing. Pressing at elevated temperatures turned out to be a crucial process step for improving the adhesive and cohesive strengths of the powder coating layer on paper. Limited mechanical interlocking with the base paper and an uneven pressure profile were factors impairing the surface strength of the coated paper. On the other hand, factors such as higher polymer content, higher pressing temperature, pre-heating the paper prior to coating, and increasing the number of hot roll nips increased adhesion between the coating and the base paper. Powder coatings as such had uneven thickness, and they displayed a relatively broad pore size distribution. [ABSTRACT FROM AUTHOR]

ABSTRACT A single biopolymer film rarely has a competitive edge against synthetic films. One solution is to combine several layers with different properties into multilayer structures. In this way, for example, the barrier properties of bio-based materials can be improved. In this study, the multilayer films are produced by combining three different techniques/materials: 1) dispersion coating (cellulose nanofibrils, CNF), 2) atomic layer deposition (Al2O3; aluminum oxide), and 3) extrusion coating (polyglycolic acid, PGA). Especially the CNF and PGA-containing multilayer films show promising oxygen barrier improvements at different humidities. Thin inorganic coatings are brittle and sensitive toward stresses during converting, which may limit their use in such specific multilayer structures. The developed bio-based films largely fulfill the barrier requirements of fresh food packaging. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42260. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the feasibility of using highly filled powders with 100 parts per weight of calcium carbonate and 10 parts per weight of polymer, acting as binder, as electrostatically applied paper coatings. Such powders prepared by different methods were evaluated as being suitable for electrostatic coating. Powders compacted at elevated temperatures demonstrated cohesion superior to that of calcium carbonate, and at best similar to that of aqueous coatings. Cohesion, porosity and thus absorption properties of compacted powders were affected by the powder preparation method, compaction process, and powder composition. Powders containing semicrystalline polymer turned out to be the most interesting for further testing. [ABSTRACT FROM AUTHOR]

Abstract: The effects of thin film nucleation and initial growth on roughness, chemistry and thermomechanical properties of polymer film surfaces were studied. Al2O3 was deposited onto commercial biaxially oriented polypropylene and polylactic acid films at 80°C by using atomic layer deposition technique. Both substrates, especially the more hydrophobic polypropylene, showed initial growth through Al2O3 clusters. There was a faster deposition of Al2O3 on polylactic acid film than on polypropylene at the early stages of the Al2O3 deposition. There were also indications of chemical interactions between polylactic acid and trimethyl aluminum used as a precursor for Al2O3. Changes in the thermo-mechanical properties of the polymer surfaces with Al2O3 also evidenced the differences between the substrate polymer films. The near surface interphase formed in polylactic acid probably contributed to the strong increase and scattering in the softening temperature during the early thin film growth. [Copyright &y& Elsevier]

The influence of surface treatments including pigment coating, surface sizing and calendering on the me-chanical strength of hotmelt adhesive joints in pilot made cartonboards was studied. The mechanical strength of the joints was investigated using the Y-peel test device at 23°C and 50% relative humidity. Some of the samples were investigated with respect to the failure mode by scanning electron microscopy. The surfaces were characterized in terms of surface roughness, surface chemical composition, and adhesion behaviour. A strong adhesive bond displayed fibre tear. In addition to fibre tear, interfacial failure, i.e., failure between the cartonboard and the adhesive, was the main reason for fracture in the bonded assembly. The most im-portant factor controlling the integrity of adhesive joints seemed to be the real contact area. The adhesive joints showed significantly higher strength when the hotmelt adhesive was first applied onto the rougher car-tonboard of the assembly and then the smoother cartonboard was pressed on the adhesive than vice versa. The surface roughness of cartonboards mainly depended on whether the surface was pigment coated or not. Calendering displayed only a minor effect. No clear influence of surface chemical composition of the cartonboards on the adhesive joint strength was found due to the fact that changes in surface chemistry in this study also led to changes in surface roughness. The strongest adhesive joint was created between two medium-rough and surface-sized cartonboards. [ABSTRACT FROM AUTHOR]

Abstract: Thin atomic layer deposited (ALD) Al2O3 coatings are efficient barriers against gases and vapors. Al2O3 coatings are, however, brittle and straining them generates defects that impair barrier properties. Flexibility of ALD-grown Al2O3 coatings on biopolymer substrates can be improved by separating thinner Al2O3 layers with inorganic–organic alucone layers. The number and size of defects were smaller for these nanolaminates compared to the thick Al2O3 films after straining, and hence straining deteriorated the oxygen barrier properties less when applied to the laminates than when applied to the Al2O3 coatings. [Copyright &y& Elsevier]

The effect of heat treatment on the gas barrier of the polymer-coated board further coated with an Al2O3 layer by atomic layer deposition (ALD) was studied. Heat treatment below the melting point of the polymer followed by quenching at room temperature was used for the polylactide-coated board [B(PLA)], while over-the-melting-point treatment was utilized for the low-density polyethylene-coated board [B(PE)] followed by quenching at room temperature or in liquid nitrogen. Heat treatment of B(PLA) and B(PE) followed by quenching at room temperature improved the water vapor barrier. However, because of the changes in the polymer morphology, quenching of B(PE) with liquid nitrogen impaired the same barrier. No improvement in oxygen barrier was observed explained by, e.g., the spherulitic structure of PLA and the discontinuities and possible short-chain amorphous material around the spherulites forming passages for oxygen molecules. This work emphasizes the importance of a homogeneous surface prior to the ALD growth Al2O3 barrier layer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Abstract: Commercial polylactide (PLA) films are coated with a thin (20nm) non-toxic polyelectrolyte multilayer (PEM) film made from sodium alginate and chitosan and additionally with a 25-nm thick atomic layer deposited (ALD) Al2O3 layer. The double-coating of PEM+Al2O3 is found to significantly enhance the water vapor barrier properties of the PLA film. The improvement is essentially larger compared with the case the PLA film being just coated with an ALD-grown Al2O3 layer. The enhanced water vapor barrier characteristics of the PEM+Al2O3 double-coated PLA films are attributed to the increased hydrophobicity of the surface of these films. [Copyright &y& Elsevier]

Abstract: Thin (25nm) and highly uniform Al2O3 coatings have been deposited at relatively low temperature of 80 and 100°C onto various bio-based polymeric materials employing the atomic layer deposition (ALD) technique. The work demonstrates that the ALD-grown Al2O3 coating significantly enhances the oxygen and water vapor barrier performance of these materials. Promising barrier properties were revealed for polylactide-coated board, hemicellulose-coated board as well as various biopolymer (polylactide, pectin and nano-fibrillated cellulose) films. [Copyright &y& Elsevier]

The growth mechanism of Atomic Layer Deposition (ALD) on polymeric surfaces differs from growth on inorganic solid substrates, such as silicon wafer or glass. In this paper, we report the growth experiments of Al2O3 and ZnO on nonwoven poly-L-lactic acid (PLLA), polyethersulphone (PES) and cellulose acetate (CA) fibres. Material growth in both ALD and infiltration mode was studied. The structures were examined with a scanning electron microscope (SEM), scanning transmission electron microscope (STEM), attenuated total reflectance-fourier-transform infrared spectroscopy (ATR-FTIR) and 27Al nuclear magnetic resonance (NMR). Furthermore, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis were used to explore the effect of ALD deposition on the thermal properties of the CA polymer. According to the SEM, STEM and ATR-FTIR analysis, the growth of Al2O3 was more uniform than ZnO on each of the polymers studied. In addition, according to ATR-FTIR spectroscopy, the infiltration resulted in interactions between the polymers and the ALD precursors. Thermal analysis (TGA/DSC) revealed a slower depolymerization process and better thermal resistance upon heating both in ALD-coated and infiltrated fibres, more pronounced on the latter type of structures, as seen from smaller endothermic peaks on TA. [ABSTRACT FROM AUTHOR]

Abstract: Thin (30–40nm) and highly uniform Al2O3 coatings have been deposited at relatively low temperature of 100°C onto various polymeric materials employing the atomic layer deposition (ALD) technique, both batch and roll-to-roll (R2R) mode. The applications for ALD have long been limited those feasible for batch processing. The work demonstrates that R2R ALD can deposit thin films with properties that are comparable to the film properties fabricated by in batch. This accelerates considerably the commercialization of many products, such as flexible, printed electronics, organic light-emitting diode lighting, third generation thin film photovoltaic devices, high energy density thin film batteries, smart textiles, organic sensors, organic/recyclable packaging materials, and flexible displays, to name a few. [Copyright &y& Elsevier]

This study explores the suitability of innovative packaging for local and organic food. Attitudes and opinions in local and organic food chains in Southern Finland were collected via eighteen semistructural interviews. The respondents were small-scale producers and processors of fish, meat, berries, and mushrooms, wholesalers, retailers, and institutional kitchens. The aim of this study was to understand factors promoting and preventing the penetration of innovative packaging solutions into the organic and local food market. A clear majority (86%) of respondents considered active and intelligent solutions to be equally suitable for local and organic food as for conventional food. However, less than half would actually use the technologies in their own products. [ABSTRACT FROM AUTHOR]

In this paper, we report ALD deposition of silicon dioxide using either thermal or plasma enhanced atomic layer deposition (PEALD). Several aminosilanes with differing structures and reactivity were used as silicon precursors in R&D single wafer ALD tools. One of the precursors was also tested on pilot scale batch ALD using O3 as oxidant and with substrates measuring 150×400mm. The SiO2 film deposition rate was greatly dependent on the precursors used, highest values being 1.5–2.0Å/cycle at 30–200°C for one precursor with an O2 plasma. According to time-of-flight-elastic recoil detection analysis measurements carbon and nitrogen impurities were relatively low, but hydrogen content increased at low deposition temperatures. [ABSTRACT FROM AUTHOR]

Abstract: This paper demonstrates opportunities for wood-based xylan derivatives to be used in coating applications. A route for extraction and purification of white and pure xylan from bleached birch kraft pulp is described as a part of the production of high adsorption and high crystalline pulp. Derivatization of the xylan during the extraction step was also demonstrated. Efficient derivatization of xylan to water soluble derivatives was achieved and promising results were obtained in primary application tests as a coating component in barrier coatings on board and as a binder component in pigment coating of offset paper. With the best xylan derivate coating, the barrier properties were better than with a commercial biopolymer coating, while oxygen permeability was roughly one third of that for a polyethylene terephthalate coating. Likewise, surface strength close to the reference latex as a binder in pigment coatings was achieved by a xylan derivative. This work is part of a platform of hemicellulose derivatives enabling novel application for this medium to high molar mass hemicellulose of high purity. [Copyright &y& Elsevier]