Novel Biocomposite of Starch and Flax Fiber Modified with Tannic Acid with Biocidal Properties.

The purpose of this paper was to develop novel biocomposites with biocidal properties in microorganisms, with enhanced mechanical strength and hydrophobicity as well as with increased biodegradation rates. The main idea and the novelty of this work was to use cross-linking compounds and, at the same time, biocidal compounds-natural compounds of plant origin with biocidal properties. The authors assumed that the modification of flax fiber by natural plant compound will reduce the hydrophilicity of novel biocompositie. Biopolymer based on thermoplastic starch reinforced with flax fibres modified with tannic acid (TA) was prepared by extrusion and injection molding processes. The effects of TA modification on the mechanical and structural properties of biocomposites were analyzed through DMA, tensile tests, DSC, and TG. The biocidal and wettability properties of the biocomposites were investigated. The article also discusses the outcomes of research conducted on the structural characteristics and rates of the biodegradation of biocomposites.

Modification of Polycaprolactone with Plant Extracts to Improve the Aging Resistance.

Natural extracts of plant origin are used as anti-aging compounds of biodegradable polymers. Coffee, cocoa, or cinnamon extracts in amounts from 0.5 to 10 wt.% were added to the polycaprolactone matrix. The manufactured materials were aged at elevated temperatures with increased relative humidity and continuous exposure to UV radiation for 720, 1440, or 2160 h. The performance of the proposed extracts was compared with the retail anti-aging compound, butylated hydroxytoluene. Visual assessment, FTIR analysis, melt flow rate, tensile strength, impact tensile strength, thermogravimetry, and differential scanning calorimetry tests were conducted. Results showed that the use of lower contents of the tested extracts is particularly advantageous. When the content of the extract did not exceed 1 wt.%, no unfavorable influence on the properties of the materials was observed. The stabilizing performance during accelerated aging was mostly similar to or greater than that of the reference compound used.

Versatile Polypropylene Composite Containing Post-Printing Waste.

The paper presents the results of the research on the possibility of using waste after the printing process as a filler for polymeric materials. Remains of the label backing were used, consisting mainly of cellulose with glue and polymer label residue. The properly prepared filler (washed, dried, pressed and cut) was added to the polypropylene in a volume ratio of 2:1; 1:1; 1:2; and 1:3 which corresponded to approximately 10, 5, 2.5 and 2 wt % filler. The selected processing properties (mass flow rate), mechanical properties (tensile strength, impact strength, dynamic mechanical analysis) and thermal properties (thermogravimetric analysis, differential scanning calorimetry) were determined. The use of even the largest amount of filler did not cause disqualifying changes in the determined properties. The characteristics of the obtained materials allow them to be used in various applications while reducing costs due to the high content of cheap filler.

The Effect of Antimony (III) Oxide on the Necessary Amount of Precursors Used in Laser-Activated Coatings Intended for Electroless Metallization.

The article presents research on the potential use of organometallic compounds with the addition of antimony (III) oxide Sb2O3 as a coating additive that will make coatings susceptible to electroless metallization after prior surface irradiation with 193 nm wavelength laser radiation and a different number of laser pulses. The surface modification and activation effects were assessed by optical-imagining as well as by scanning electron microscopy (SEM) with energy dispersive analysis (EDX). It was found that the presence of Sb2O3 in the coating made it possible to reduce the content of the copper complex, causing an intensive surface ablation, resulting in the formation of a conical structure with a higher content of metallic copper nuclei.

Copper Filled Poly(Acrylonitrile-co-Butadiene-co-Styrene) Composites for Laser-Assisted Selective Metallization.

Selective metallization of polymeric materials using the technique known as laser direct structuring (LDS) is intensively developed. In this technique, metallized products can be manufactured by injection molding or by 3D printing process if rapid prototyping is need. Special additives present in the polymer matrix enable direct electroless metallization only on the surface which was laser activated. This paper presents the results of using copper microparticles introduced into the poly(acrylonitrile-butadiene-styrene) (ABS) matrix at various amounts (up to about 5 vol %). ABS was selected due to its good processing and mechanical properties and as one of the most common thermoplastics used in 3D printing. The influence of copper on structural, mechanical, and processing properties as well as on the effects of laser surface activation were determined. Two types of infrared lasers were tested for surface activation: Nd:YAG fiber laser (λ = 1064 nm) and CO2 laser (λ = 10.6 µm). Various irradiation parameters (power, scanning speed, and frequency) were applied to find suitable conditions for laser surface activation and electroless metallization. It was found that the composites tested can be effectively metallized using the Nd:YAG laser, but only in a narrow range of radiation parameters. Activation with CO2 laser failed, regardless of applied irradiation conditions. It resulted from the fact that ablation rate and thickness of modified surface layer for CO2 were lower than for Nd:YAG laser using the same irradiation parameters (power, speed, and frequency of laser beams), thus the laser wavelength was crucial for successful surface activation.

Composting of Polylactide Containing Natural Anti-Aging Compounds of Plant Origin.

The paper presents the effects of biodegradation of polylactide containing natural anti-aging compounds. Polymer containing 0.5; 5 and 10 wt % of coffee, cocoa or cinnamon extracts were subjected to industrial composting for 7, 14, 21 or 28 days. The effect of the composting process on polylactide properties was examined based on visual assessment, scanning electron microscopy, average molecular weight, differential scanning calorimetry, thermogravimetry, and tensile strength. The impact of the tested extracts on the effects of the composting process was compared with the impact of a commercially available anti-aging compound. It was found that the tested extracts in most cases did not adversely affect the effects of the composting process compared to pure polylactide, often resulting in intensification of biodegradation processes. As a result of the composting process, changes in the macro- and microscopic appearance of the samples and a decrease in molecular weight, phase transition temperatures, thermal resistance, and thermal strength were observed on a scale close to or greater than the reference anti-aging compound.

The Effect of Accelerated Aging on Polylactide Containing Plant Extracts.

In this study, natural extracts of plant origin were used as anti-aging compounds of biodegradable polymers. Coffee (0.5⁻10 wt%), cocoa, or cinnamon extracts were added to the polylactide matrix. The obtained materials were subjected to an accelerated aging process (720, 1440, or 2160 h) at 45 °C and 70% relative humidity under continuous UV radiation. The effectiveness of the tested extracts was compared to a commercially available anti-aging compound, 2 wt% of butylated hydroxytoluene. Visual evaluation, scanning electron microscopy, melt flow rate, thermogravimetry, differential scanning calorimetry, tensile strength, and impact tensile tests were performed. We show that the use of smaller amounts of tested extracts is particularly advantageous, which do not adversely affect the properties of polylactide-based materials at low contents. At the same time, their effectiveness in stabilizing tested properties during the accelerated aging process is mostly comparable to or greater than the reference compound.