Pyrolysis kinetics of ZrP-containing aliphatic waterborne polyurethane-based intumescent coating for flame-retarding plywood

Photo‐aging deterioration of hybrid intumescent flame retarding coatings simultaneously modified by silicon aerogel, β‐cyclodextrin, and nano‐ZnO

“…Firstly, 8 g APP was dispersed into 10 g deionized water under magnetic stirring of 500 rpm at 25 C. The 0.56 g Nano-ZnO was preferentially modified by 0.18 g chemical coupling reagent in 5 g water during stirring. Then 20 g AWP, 5 g starch, 0.55 g β-CD, 0.22 g silicon aerogel, 0.1 g PAM, 0.2 g PDMS, 0.7 g urea, and modified ZnO were sequentially added into the APP solution to achieve the preparation of the pristine coating, the dosage was referred to our previous research, 11,12 followed by another vigorous stirring at 1000 rpm (25 C) about 10 min, which was served as the control named S. Finally, the IFRC was manually brushed 3 times (in 1 h) on the plywood surface with a drying coating thickness of 0.35 ± 0.01 mm. It was tested by a vernier caliper with an error of 0.01 mm, which was obtained from the average value of five results collected in the four sides and the center of the sample, according to the ASTM D 7091-05, using the average value of three determinations as to the final thickness of coatings.…”

“…According to BS ISO 5660-1:2015, the cone calorimeter (CC, ZY6243, Zhongnuo instrument company, China) was exploited to evaluate the fireproof performance of the IFRC under an external radiation flux of 35 kWÁm À2 , 11,12 which was brushed on the plywood (100 Â 100 Â 3 mm 3 , enwrapped in aluminum foil) with an exposed burning area of 0.0088 m 2 . The following parameters were obtained to quantitatively evaluate the fireproof property, heat release rate (HRR) (the whole curve by plotting the released heat against the time, HRR, kWÁm À2 ), time to ignite (TTI, s), the peak of HRR (the highest point on the HRR curve, p-HRR, kWÁm À2 ), time to p-HRR (T p , s), total heat release (THR, MJÁm À2 ), total smoke production (TSP, m 2 ) for evaluating the smoke-suppression performance, weight loss during burning (WL b , g), and average effective heat of combustion (AEHC, MJÁkg À1 ) calculated by the formula (1).…”

“…Additively, the flame retardancy index (FRI) was calculated by the formula (4), which was divided into three levels including "FRI < 1"; "1 < FRI < 10", and "10 < FRI < 100" corresponding to "Poor", "Good", and "Excellent" fire retardancy, respectively. 11,12 Furthermore, the swelling rate (SR) was defined as the ratio of the swelling height of residue to the pristine thickness of the IFRC, which was used to evaluate its fire-swelling property.…”

“…The thermal gravimetric and differential scanning calorimetry (TG/DSC) was tested by the Mettler analyzer (Germany) under pure N 2 atmosphere, the sample temperature, weight loss, and heat flow were real-timely recorded from 50 to 1000 C with a heating rate of 10 CÁmin À1 . 11,12 3 | RESULTS…”

“…10 Furthermore, our previous research has facilely prepared an organic-inorganic hybrid IFRC using the aliphatic waterborne polyurethane (AWP) as the binder, which could transform into a continuous and uniform film under room temperature. 11,12 Consequently, a novel IFRC is preliminarily fabricated using the AWP as the binder, the flame-retarding system consists of APP (acid source), urea (gas source), starch and β-CD (carbon source), as well as the silicon aerogel, and nano-ZnO as the modifiers, the polyacrylamide (PAM) and polydimethylsiloxane (PDMS) as the assistants, the formulation is determined by a large number of trials and measurements.…”