Characterization of the physical properties 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.

• Presented comparison between the recycled wind turbine blade composites and woodbase composites shows the potential utilization of this recycled material in different fields.
• Thickness swelling and water sorption of recycled wind turbine blade composites presented that give the researchers clear vision about their physical properties.• Researchers could be referred to this dataset to design and analyze different experiments on recycled win turbine blades.

Data
For obtaining physical properties of composites fabricated using recycled wind turbine blade materials, water sorption and thickness swelling were performed based on ASTM D1037-12.Presented dataset include influence of refined particle size, resin content and coupling agents (maleic anhydride polyethylene (MAPE) and methacryloxypropyltriethoxysilane (Silane)) on the physical properties of recycled composites.

Materials
Recycled wind turbine blade (rWTB) material was supplied by Global Fiberglass Solutions at an incoming moisture content of 1.25%.A high-density polyethylene (HDPE) (0.3 MFI) was obtained from a commercial vender and used as the matrix for the second-generation extruded composite.The rWTB material was hammer-milled through 3.18, and 1.59 mm screen size (MSS) and particle size distribution of the refined material was performed with Ro-Tap sieve analysis procedures [2].A commercially available 60-mesh pine (P.stobus) was used for baseline comparison to the rWTB filled extrudate.Methacryloxypropyltrimethoxysilane (Silane) (Gelest Inc.) and maleic anhydride polyethylene (MAPE) were used as the coupling agents [3].

Extruded rWTB composite preparation
The various milled size fractions of rWTB material were mixed with high density polyethylene, non-metallic stearate lubricant, MAPE and silane as coupling agents were also added to the formulation.Silane was received in a liquid form and sprayed to rWTB materials.They were then blended for 15 minutes and dried for 10 hours at 60 C in an oven [4].MAPE was added to the dry blend as a pellet.For comparison purposes, a commercial 60-mesh pine was used as a feedstock source.

Thickness swell and water sorption properties
To evaluate the thickness swell and water sorption of extruded rWTB composites, water immersion studies were performed in accordance with ASTM D1037-12 [5].The samples were immersed until samples achieved an equilibrium state, where a negligible change in sample mass was observed or reached 2000 hours of immersion.The reference for the test was the composite (WPC) made from 60-mesh pine wood flour.
Comparing the data of thickness swell and water sorption for rWTB composites with WPCs shows a significant influence of rWTB material to reduce water sorption and thickness swell of extruded composites.After 2000h of water immersion, the thickness swell of composites with 0% pine (55% rWTB) was dramatically lower than the wood filled composite Due to the hydrophilic nature of wood, the addition of pine flour to the composite an expected increased the thickness swelling and water sorption was observed.However, even at a low loading of wood flour (13%) there was a 3x increase in dimensional change and weight gain compared to the composites with only rWTB material Considering the influence of MSS on the thickness swelling of composites, reducing the MSS from 3.18 mm to 1.59 mm had no visible influence on thickness swelling of composites.However, with water sorption, there did appear to be a slight increase in water uptake with the larger MSS material as seen in Tables 2 and 3.
Modifying the composites with MAPE reduced the water sorption of composites significantly.
Increasing the rWTB content up to 70% increased water sorption as well on the contrary, modifying the extruded composites with silane increased the water sorption and thickness swell of composites as shown in Tables 2 and 3.

Table 2 .
Water sorption of rWTB composites