Physical properties data of extruded composites from recycled wind turbine blade material.

Wind turbine blades (WTB) mechanically recycled and used as a feedstock for thermoplastic composites. Physical properties (water sorption (WA), Thickness swelling (TS)) dataset of composites made from recycled wind turbine blades presented. Dataset also presented the influence of resin level, mill screen size and coupling agents on the physical properties of composites (Mamanpush et al., 2019).

Experimental data on the mechanical and thermal properties of extruded composites from recycled wind turbine blade material.

The wind turbine blades (WTB) that face end-of-life was first mechanically milled and classified through a range of varying screen sizes. We then blended this with high density polyethylene (HDPE) thermoplastic resin and extruded it to a profiled composite. We determined the influence of refined particle size, resin content and coupling agents (maleic anhydride polyethylene (MAPE) and methacryloxypropyltriethoxysilane (Silane)) on the mechanical and CLTE properties of recycled composites (Mamanpush et al., 2019).

Dataset demonstrating physical properties of recycled wind turbine blade composites.

Wind turbine blades that face end-of-life recycled mechanically. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resinated and compressed to a final thickness to manufacture second generation composites fabricated using recycled wind turbine material and a polyurethane adhesive. Physical properties (water sorption (WA), Thickness swelling (TS)) dataset of composites made from recycled wind turbine blades presented. Dataset also presented the influence of resin level, moisture content, mill screen size and density on the physical properties of composites.

Data on the mechanical properties of recycled wind turbine blade composites.

Wind turbine blades that face end-of-life recycled mechanically. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resonated (polymeric Methylene diphenyl isocyanate (pMDI)) and then hand-formed and hot pressed. The hot press temperature and time were set as 138 °C and 5 min accordingly, typical for pMDI composite processing. Mechanical properties (Modulus of rupture (MOR), Module of elasticity (MOE) and Internal bond(IB)) dataset of composites made from recycled wind turbine blades(rWTBs) presented. Dataset also presented the influence of resin level, moisture content, mill screen size and density on the mechanical properties of composites [1], [2].

Recycled wind turbine blades as a feedstock for second generation composites.

With an increase in renewable wind energy via turbines, an underlying problem of the turbine blade disposal is looming in many areas of the world. These wind turbine blades are predominately a mixture of glass fiber composites (GFCs) and wood and currently have not found an economically viable recycling pathway. This work investigates a series of second generation composites fabricated using recycled wind turbine material and a polyurethane adhesive. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resinated and compressed to a final thickness. The refined particle size, moisture content and resin content were assessed for their influence on the properties of recycled composites. Static bending, internal bond and water sorption properties were obtained for all composites panels. Overall improvement of mechanical properties correlated with increase in resin content, moisture content, and particle size. The current investigation demonstrates that it is feasible and promising to recycle the wind turbine blade to fabricate value-added high-performance composite.

Analysis and evaluation of a fruit bin for apples.

A fruit bin is an essential part of apple harvesting, storage, and transport. The lateral pressure distribution on the bin walls by apples in the bin are not well understood, thus making it harder to predict the behavior of the vertical walls of the bin. In this study, a bin was loaded with apples and deflections of the base and a vertical wall were experimentally measured and then modeled using finite element methods to understand typical static load distribution. One of the factors determining the accuracy of an analytical model is accurate representation of load distribution on the structure. A mathematical model was used to validate the lateral pressure distribution applied by the apples on the vertical walls and the bottom plate of the bin. The effect of unit weight of an apple and the angle of repose of apples on load distribution in the bin has been analyzed. Angle of repose is found to be a significant parameter for the lateral pressure distribution on the bin walls. A nonlinear lateral pressure distribution was observed along the depth from top to bottom of the bin. The resulting finite element model allows for comparison of deformation behavior of fruit bins constructed with a variety of materials, such as plywood, wood plastic composites, or a thermoplastic polymer. Although this study dealt with bins for apples, the sensitivity analyses for a range of unit weights and angles of repose for apples makes the analysis results versatile for use with other kinds of fruits and vegetables that fall within the reported range of unit weight and angle of repose.

Rheological properties and tunable thermoplasticity of phenolic rich fraction of pyrolysis bio-oil.

In this work we report on the preparation, characterization, and properties of a thermally treated lignin-derived, phenolic-rich fraction (PRF) of wood pyrolysis bio-oil obtained by ethyl acetate extraction. The PRF was characterized for viscoelastic and rheological behavior using dynamic mechanical analysis (DMA) and cone and plate rheology. A unique thermoplastic behavior was evidenced. Heat-treated PRFs acquire high modulus but show low temperatures of thermal flow which can be systematically manipulated through the thermal pretreatment. Loss of volatiles, changes in molecular weight, and glass transition temperature (Tg) were investigated using thermogravimetric analysis (TGA), mass spectrometry (MS), and differential scanning calorimetry (DSC), respectively. Underlying mechanisms for the thermal and rheological behavior are discussed with regard to interactions between pyrolytic lignin nanoparticles present in the system and the role of volatile materials on determining the properties of the material resembling in several aspects to colloidal suspension systems. Low thermal flow temperatures and reversible thermal effects can be attributed to association of pyrolytic lignin particles due to intermolecular interactions that are easily ruptured at higher temperatures. The thermoplastic behavior of PRF and its low Tg is of particular interest, as it gives opportunities for application of this fraction in several melt processing and adhesive technologies.

Production of natural fiber reinforced thermoplastic composites through the use of polyhydroxybutyrate-rich biomass.

Previous research has demonstrated that production of natural fiber reinforced thermoplastic composites (NFRTCs) utilizing bacterially-derived pure polyhydroxybutyrate (PHB) does not yield a product that is cost competitive with synthetic plastic-based NFRTCs. Moreover, the commercial production of pure PHB is not without environmental impacts. To address these issues, we integrated unpurified PHB in NFRTC construction, thereby eliminating a significant energy and cost sink (ca. 30-40%) while concurrently yielding a fully biologically based commodity. PHB-rich biomass synthesized with the microorganism Azotobacter vinelandii UWD was utilized to manufacture NFRTCs with wood flour. Resulting composites exhibited statistically similar bending strength properties despite relatively different PHB contents. Moreover, the presence of microbial cell debris allowed for NFRTC processing at significantly reduced polymer content, relative to pure PHB-based NFRTCs. Results further indicate that current commercial PHB production yields are sufficiently high to produce composites comparable to those manufactured with purified PHB.

Synthesis of polyhydroxyalkanoates in municipal wastewater treatment.

Biologically derived polyesters known as polyhydroxyalkanoates (PHAs) represent a potentially "sustainable" replacement to fossil-fuel-based thermoplastics. However, current commercial practices that produce PHA with pure microbial cultures grown on renewable, but refined, feedstocks (i.e., glucose) under sterile conditions do not represent a sustainable commodity. Here, we report on PHA production with a mixed microbial consortium indigenous to an activated sludge process on carbon present in municipal wastewaters. Reactors operated under anaerobic/aerobic and aerobic-only mode and fed primary solids fermenter liquor maintained a mixed microbial consortium capable of synthesizing PHA at 10 to 25% (w/w), while reducing soluble COD by approximately 62 to 71%. More critically, an aerobic batch reactor seeded from the anaerobic/aerobic reactor and fed fermenter liquor achieved approximately 53% PHA (w/w). Results presented suggest that environmentally benign production of biodegradable polymers is feasible. We further used PHA-rich biomass to produce a natural fiber-reinforced thermoplastic composite that can be used to offset advanced wastewater treatment costs.

Fungal upgrading of wheat straw for straw-thermoplastics production.

Combining biologic pretreatment with storage is an innovative approach for improving feedstock characteristics and cost, but the magnitude of responses of such systems to upsets is unknown. Unsterile wheat straw stems were upgraded for 12 wk with Pleurotus ostreatus at constant temperature to estimate the variation in final compositions with variations in initial moisture and inoculum. Degradation rates and conversions increased with both moisture and inoculum. A regression analysis indicated that system performance was quite stable with respect to inoculum and moisture content after 6 wk of treatment. Scale-up by 150x indicated that system stability and final straw composition are sensitive to inoculum source, history, and inoculation method. Comparative testing of straw-thermoplastic composites produced from upgraded stems is under way.