ABSTRACT:The method of boroorganic compounds preparation by esterification of boric acid and glycols has been presented. The obtained compounds tri(2-hydroxybutyl)borate, tri(hydroxythiodiethylene)borate, tri[(3-chloro-2-hydroxy-1-propoxy)-1-methylpropyl]borate, and tri[3-chloro-2-hydroxy-1-propoxy)thiodiethyl]borate were used to produce the rigid polyurethane-polyisocyanurate (PUR-PIR) foams. The foams were prepared by one-stage method and the amount of borates added varied, within the range from 0.0 to 0.4 of chemical equivalent. The method of preparation, determination of foaming parameters, and methods of testing of the physicochemical properties of PUR-PIR foams as well as their results have been presented. A special emphasis was put on reduction of the foam flammability. It was found that application of the obtained compounds as polyolic components has a favorable effect on the properties of the produced rigid PUR-PIR foams. The obtained rigid PUR-PIR foams were characterized by a higher compressive strength, lower brittleness, considerably reduced flammability, and higher content of the closed cells.
Rigid polyurethane-polyisocyanurate foams (PUR-PIR) containing from 2.5% to 20% w/w of fillers (talc, aluminum hydroxide, chalk, starch and borax) were the subject of our studies; a reference sample was PUR-PIR foam with no filler added. Apparent density, compressive strength, brittleness, content of closed cells, retention (flammability) and softening point of foams were determined and the products were analyzed by thermogravimetric method. These parameters were the basis to determine effect of type and participation of the fillers studied on physicochemical, heat, and thermal properties of foams.
Four types of rigid polyurethane-polyisocyanurate foams (RPU/PIR) were obtained. Three of them were modified by powder fillers, such as cinnamon extract (C10 foam), green coffe extract (KZ10), and cocoa extract (EK10) in an amount of 10 wt %. The last foam was obtained without a filler (W foam). The basic properties and thermal properties of obtained foams were examined. All foams were subjected to degradation in the climatic chamber acting on samples of foams in a defined temperature, humidity, and UV radiation for 7, 14, and 21 days. The physico-mechanical properties of foams were tested. The compressive strength of degraded foams after 7, 14, and 21 days was compared with the compressive strength of nondegraded foams (0 days). The chosen properties of degraded foams, such as cellular structure by scanning electron microscopy (SEM) and changes of chemical structure by FTIR spectroscopy were compared. The obtained foams were also subjected to degradation in a circulating air dryer in an increased temperature (120 °C) for 48 h. Additionally, W, C10, ZK10, EK10 foams were placed in a soil environment and subjected to 28 days biodegradation process. The biochemical oxygen demand (BOD), the theoretical oxygen demand (TOD), and the degree of biodegradation (Dt) of foams were determined in this measurment. Test results showed that the compressive strength of foams decreased with the longer time of foam degradation in the conditioner. The foam subjected to degradation darkened and became more red and yellow in color. The addition of natural compounds of plant origin to foams increased their susceptibility to biodegradation.
Glycolysis of rigid polyurethane-polyisocyanurate foams Summary-A rigid polyurethane-polyisocyanurate foam (PUR-PIR) was synthesized. Then it was ground in a plastic shredder and a ball mill. The resulting milling product was then glycolysed in diethylene glycol with addition of ethanolamine and zinc stearate. The foam was added at consecutive stages in batches, so that the total amount of the foam at consecutive stages was 20, 40 and 60 g. The resulting product of each stage was a brown liquid (WI, WII and WIII). Properties of these products were then investigated in order to determine their usability to synthesize new foams. It was found that the best reusable was the WIII glycolysate and adding it in various quantities 3 new foams (GW0.1, GW0.2 and GW0.3) were obtained. Properties of these foams were investigated and as a result usability of the glycolysates to produce PUR-PIR foams was stated.
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