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Highlights • Biochar, a carbon rich material is porous and thermally stable. • Addition of biochar improves the physico-mechanical properties of composites. • Coupling agent is more effective in HDPE-wood fiber matrix than biochar. • Biochar improves the thermal stability and reduces water absorption of composites. Abstract Bio-composite samples were manufactured using poly (lactic acid) (PLA), high density polyethylene (HDPE), biochar, wood flour, and coupling agent. Biochar, a carbon rich and thermally stable material, derived from switchgrass under controlled pyrolysis was tested as a functional filler. The study aimed at investigating the impact of biochar and wood fiber in the presence of coupling agent (maleic anhydride) on the properties of bio-composites. The bio-composite physical, mechanical and thermal properties were characterized using microscopy, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), Fourier transform-infrared spectroscopy (FT-IR). The results showed that coupling agent is more compatible with wood flour than biochar. Addition of biochar reduced the moisture absorption and linear thermal expansion of filled bio-composites. It also improved the composites strength and moduli, showing a reinforcing nature of biochar. The TGA thermograms confirmed the improved stability of composites with biochar. Coupling agent was more effective in HDPE matrix reinforced by wood flour than biochar. Overall, this study demonstrated that biochar can be a good filler for improving dimensional stability, mechanical properties, and thermal stability of bio-composites. [ABSTRACT FROM AUTHOR]

To manage the plastic waste, recycling is recognized as the most environment-friendly and non-destructive method. The aim of this research is to investigate the recyclability of oak wood flour (WF) filled high density polyethylene (HDPE) composites. Two different composite formulations (30 and 50 wt% filler) were considered, each with 3 wt% coupling agent maleic anhydride (MA). Both composites were individually reprocessed six times by extrusion. Test samples were injection molded, to measure mechanical and thermo-mechanical properties. Fiber length measurement and gel permeation chromatography (GPC) were performed respectively to examine the change on fiber length and molecular weight of polymer. Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), and Fourier Transform Infra-Red Spectroscopy (FTIR) were also carried out to better understand the impact of recycling on composite properties. After reprocessing six times, WF-HDPE composites showed relative decrease in strength and stiffness properties and slight increase in strain properties as compared to corresponding virgin composite. The strain properties saw an increase in their value with recycling. The crystallinity of HDPE decreased but thermal stability of the composite increased with reprocessing. [ABSTRACT FROM AUTHOR]

• A new soy-based coating is investigated for corrosion mitigation in rebars. • Physical and chemical characteristics of soy protein coatings are evaluated. • Soy-based coatings exhibited promising corrosion protection and abrasion resistance. • Coating with 15% wt. SPI and 30% wt. sorbitol exhibited the highest corrosion protection. • Proposed soy-based coatings can be used for in-situ repairs of damaged rebar coatings. Different corrosion mitigation strategies (e.g. corrosion inhibitors, coatings) are employed in the construction industry to mitigate chloride-induced corrosion in bridge decks and reinforced concrete pavements. While epoxy coatings are effective in mitigating rebar corrosion, their local damage during transportation may lead to aggressive pitting corrosion. Besides, epoxy coatings cannot be repaired in-situ due to their toxic nature and requirement for special equipment. In this study, a new soy-based coating material is investigated which can be applied in-situ for protecting rebar from corrosion and repairing damaged epoxy coated rebars. Soy-based coatings are synthesized using denatured soy protein isolate (SPI) (5–15% wt. in deionized water) and corn-derived sorbitol plasticizer (10–30% wt. of SPI). The physical and chemical characteristics of the soy-based coatings and their corrosion protection performance are evaluated for cement mortar embedded SPI coated rebars. The results obtained from FTIR, viscosity, and abrasion tests demonstrated that soy-based coatings have an adequate abrasion resistance and include necessary functional groups for usage as a corrosion protection coating material. The potentiodynamic polarization tests results showed that soy protein coatings significantly reduce the corrosion current density (up to 96% when compared to bare rebar) in a simulated concrete pore solution that contained 3.5% wt. sodium chloride. The long-term corrosion data obtained from rapid macrocell corrosion tests showed that soy protein-coated rebars incur lower corrosion rates and exhibited a stable corrosion potential as compared to bare rebar specimens. Overall, the soy protein coating formulation with 15% wt. SPI and 30% wt. sorbitol exhibited the highest corrosion protection and abrasion resistance. The proposed soy protein coating materials can be used for in-situ repairs of damaged rebar coatings in aggressive chloride environments and as a standalone coating in moderately corrosive environments. [ABSTRACT FROM AUTHOR]

• The effect of polyol corrosion inhibitors on cement mortar properties is evaluated. • Physical and chemical characterization performed after mortar deicer wet-dry cycles. • Polyol corrosion inhibitors showed no negative impact on cement mortar properties. • Polyol-based NaCl deicer mitigate corrosion without affecting mortar performance. This study aims to investigate the influence of polyol corrosion inhibitors on the properties of cement mortar by exposing mortar samples to 90 wet-dry cycles of sodium chloride (NaCl) solution that contained 1%w/w of three polyol corrosion inhibitors. Scaling rating, mass-change, and compression tests, and chemical characterization tests performed at regular intervals revealed that polyol-based NaCl deicers cause less than 10% decrease in mortar compression strength and incurred slight-to-moderate scaling whereas NaCl deicer caused up to 17% reduction in compression strength and incurred slight-to-moderate or moderate scaling. Polyol corrosion inhibitors did not result in any further deterioration in mortar properties when compared to NaCl and hence they can be used for mitigating rebar corrosion without compromising properties of hardened cementitious materials. [ABSTRACT FROM AUTHOR]

• Biobased MSP coatings are investigated for the corrosion mitigation of rebars. • Physical, chemical, mechanical, and electrochemical properties of MSP coatings are evaluated. • MSP coatings exhibit enhanced abrasion resistance, promising corrosion protectionperformance, and superior bond performance. • MSP-10-10-10 revealed 94% and 78% improvement in short-term and long-term corrosion rates. • MSP coatings can be employed as a stand-alone option for the in-situ repair of damaged coatings. While epoxy coatings effectively prevent rebar corrosion, they can sustain damage during transportation, making them susceptible to localized corrosion during service. Additionally, these coatings can reduce the bond strength with concrete by over 20%, necessitating an increase in development length. Although soy-protein coatings could potentially repair damaged epoxy coatings in the field, they may further reduce the bond strength. This study aims to enhance the corrosion resistance of soy-protein isolate (SPI) coatings without undermining their bond with concrete. To achieve this, five new coating formulations were prepared by blending chemically inert oxide abrasives into SPI coatings in varying proportions. These modified soy-protein coatings were then assessed through physical, chemical, mechanical, and electrochemical analyses to measure their improvements. Adding abrasives beyond a certain weight proportion increased the viscosity and thickness of the coatings, improving their mechanical properties, including abrasive resistance and lap shear strength. Potentiodynamic polarization tests and macrocell analyses revealed a 94% and 78% improvement in short-term and long-term corrosion performance respectively. Moreover, when compared to conventional SPI coatings, the bond strength of the modified soy-protein coatings improved by up to 90.41%. In conclusion, SPI coatings infused with abrasives outperform traditional SPI coatings and could serve as superior secondary coats. They could even be considered as stand-alone coatings for rebars. [ABSTRACT FROM AUTHOR]

• Tests are performed to demonstrate the corrosion inhibition efficiency of polyols. • Addition of polyols to salt brine deicer can reduce the corrosion rates up to 92%. • Polyols acted as mixed-type corrosion inhibitors in the salt brine deicer. • Physisorption of polyol molecules on the steel surface led to corrosion inhibition. The goal of this study is to reduce the corrosivity of traditional pavement deicers by employing environmentally safe and low-cost corn-derived polyols namely sorbitol, mannitol, and maltitol. The corrosion inhibition performance of polyols-mixed deicers is investigated for ASTM A572 Gr. 50 high strength low alloy steels. For this purpose, each polyol is added to the traditional deicer (23.0% wt. sodium chloride brine) in the following weight concentrations: 0.5%, 1.0%, 2.0% and 3.0%. The corrosion behavior of ASTM A572 Gr. 50 high strength low alloy steel is then quantified by conducting potentiodynamic polarization tests in the absence and presence of different polyols concentrations in the deicing solution. In addition to the polarization tests, accelerated corrosion tests are performed by continuously subjecting ASTM A572 Gr. 50 steel specimens to the periodic flow of polyols-based deicers in a hot and humid environment inside an environmental chamber to visually monitor the corrosion damage in steel specimens. The results obtained from both polarization tests and accelerated corrosion tests revealed that the addition of small concentrations of corn-derived polyols in the traditional salt brine deicer leads to substantial corrosion inhibition (up to 92%) in the ASTM A572 Gr. 50 steel used in this study. All three polyols are observed to obey the Langmuir's adsorption isotherm and inhibit the corrosion in ASTM A572 Gr. 50 steels through physical adsorption on the steel surface. The potentiodynamic polarization test results further indicated the mixed-type corrosion inhibiting nature of polyols-based deicing solutions. [ABSTRACT FROM AUTHOR]