Laboratory scale

During the experimental part, a laboratory scale (Sartorius, Göttingen, Germany), a homogenizer, a zetameter (ZetaPlus, Brookhaven, Holtsville, NY, USA), and a contact angle measurement apparatus (GBX, Rhone, France) were used.

MVF, FVF, and VVF (eqn (2)) for the composites and recycled fibres are determined in two ways. (I) Samples of 20–50 mg are pyrolysed (N₂ atmosphere) in a TGA (TG 209 F1 Libra, Netzsch) in the temperature range from 35 °C to 800 °C, 10 K min⁻¹. (II) 10 g samples are burned in a furnace at 500 °C for six hours in normal lab atmosphere; weighted before and after the burnout. where m_e is lost epoxy matrix mass and m_f is remaining fibre mass. Epoxy matrix and fibre densities are ρ_e = 1.17 g mL⁻¹ and ρ_f = 1.81 g mL⁻¹, respectively. The composite density (ρ_c) is found via Archimedes' principle (eqn (3)). where the mass of the composite sample (m_c) and the mass of the displaced water (m_w), when the composite is submerged in demineralized water (ρ_w = 0.998 g cm⁻³ at 20 °C), is weighed on laboratory scale (Sartorius) at ambient temperature.

Diabetes was induced in twelve rats by streptozotocin (Sigma-Aldrich Chemical Co., St. Louis, MO, USA; administered intraperitoneally at 60 mg/kg body weight) and monitored with a One Touch Ultra 2 Glucometer^® (Life scan Inc., Milpitas, CA, USA). Rats with a blood glucose ≥250 mg/dL 5 days after streptozotocin injection were used for the study. The weights were taken at the beginning and end (after 5 days) of the experiment using a laboratory scale (Sartorius, Goettingen, Germany).