Hydroxyalkylation of Cyclic Imides with Oxiranes. Part II. The Mechanism of Reaction in Presence of Triethylamine

Kahane Ernest. J. Fourastié, Les conditions de l'esprit scientifique, Coll. Idées. In: Raison présente, n°1, Novembre – Décembre – Janvier 1966. Psychologie & philosophie. pp. 131-133

The biodegradable cellulose-derived polyol and polyurethane foam

The method of polyol synthesis from cellulose, glycidol, and ethylene carbonate in water was elaborated. The obtained polyol was characterized by IR, 1H NMR and MALDI ToF spectroscopy. The polyol was then used to obtain rigid polyurethane foam. That foam have apparent density, water uptake, and polymerization shrinkage similar to conventional rigid polyurethane foams. The foam showed advantageous thermal resistance in comparison with classic ones. After thermal exposure its compressive strength was improved. The polyol is totally biodegradable in soil. The polyurethane foam obtained from this polyol was 70–80% biodegraded in soil within 28 days

Hydroxyalkylation of Cyclic Imides with Oxiranes. Part II. The Mechanism of Reaction in Presence of Triethylamine

The mechanism of reaction of cyclic monoimides with oxiranes was established based upon kinetic studies and product analysis. It has been established that the reaction proceeds through initial formation of an adduct of imide and triethylamine. The crucial bond in adduct has ionic character; in non-aqueous solvents it is present as ion pair, while in water the adduct dissociate and free ions are present. The adduct enables the proton transfer from imide to oxirane. The rate determining step is reaction of imide and this adduct. Different values of entropy of transition states obtained from thermodynamic calculations suggest slightly different structure of transition state of rate determining step

Polyurethane Foams with Pyrimidine Rings

Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthetic composition. The thermal resistance was studied by dynamic and static methods with concomitant monitoring of compressive strength. The polyurethane foams have similar physical properties as the classic ones except their enhanced thermal resistance. They stand long-time heating even at 200°C. Moreover thermal exposition of foams results generally in increase of their compressive strength

Polyols and Polyurethane Foams Obtained from Mixture of Metasilicic Acid and Cellulose

Hydroxyalkylation of the mixture of metasilicic acid and cellulose with glycidol and ethylene carbonate leads to a polyol suitable to obtain rigid polyurethane foams. The composition, structure, and physical properties of the polyol were studied in detail. The obtained foams have apparent density, water absorption, and polymerization shrinkage, as well as heat conduction coefficients similar to conventional, rigid polyurethane foams. The polyols and foams obtained from environmentally unobtrusive substrates are easily biodegradable. Additionally, the obtained foams have high thermal resistance and are self-extinguishing. Thermal exposure of the foams leads to an increase of the compressive strength of the material and further reduces their flammability, which renders them suitable for use as heat insulating materials

Polyurethane foams with 1,3,5-triazine ring and silicon

W wyniku zmieszania oligoeteroli z pierścieniem 1,3,5-triazynowym i atomami krzemu uzyskano poliol nadający się do otrzymywania sztywnej pianki poliuretanowej. Zbadano właściwości fizyczne i użytkowe otrzymanej pianki: gęstość pozorną, chłonność wody, stabilność wymiarów, współczynnik przewodzenia ciepła, odporność termiczną i właściwości ogniowe. Stwierdzono, że charakteryzuje się ona zwiększoną wytrzymałością mechaniczną i odpornością termiczną w stosunku do klasycznych, sztywnych pianek poliuretanowych oraz zmniejszoną szybkością palenia. Podczas długotrwałego wygrzewania w temperaturze 150-200°C następuje wzrost jej wytrzymałości na ściskanie. Pianka poddana ekspozycji w temperaturze 150°C w ciągu miesiąca staje się samogasnąca, a wygrzewana w temperaturze 175°C - niepalna.By mixing oligoetherols with 1,3,5-triazine rings and silicon atoms, polyol suitable for the preparation of rigid foam polyurethanes were obtained. The physical and utility properties of the obtained foam as well as bulk density, water absorption, dimensional stability, thermal conductivity, heat resistance and fire properties were examined. It has been found that it is characterized by improved mechanical strength, heat resistance and a reduced rate of smoking compared with conventional rigid polyurethane foams. During the prolonged heating of the foam at a temperature of 150-200°C its compressive strength increases. The foam subjected to exposure at 150°C and at 175°C during the month becomes self-extinguishing and non-flammable respectively

Use of a Mixture of Polyols Based on Metasilicic Acid and Recycled PLA for Synthesis of Rigid Polyurethane Foams Susceptible to Biodegradation

Two polyol raw materials were obtained in the conducted research, one based on metasilicic acid (MSA), the other based on poly(lactic acid) (PLA) waste. The obtained polyols were characterized in terms of their applicability for the production of rigid polyurethane foams (RPUFs). Their basic analytical properties (hydroxyl number, acid number, elemental analysis) and physicochemical properties (density, viscosity) were determined. The assumed chemical structure of the obtained new compounds was confirmed by performing FTIR and 1H NMR spectroscopic tests. Formulations for the synthesis of RPUFs were developed on the basis of the obtained research results. A mixture of polyols based on MSA and PLA in a weight ratio of 1:1 was used as the polyol component in the polyurethane formulation. The reference foam in these tests was a foam that was synthesized only on the basis of MSA-polyol. The obtained RPUFs were tested for basic functional properties (apparent density, compressive strength, water absorption, thermal conductivity coefficient etc.). Susceptibility to biodegradation in soil environment was also tested. It was found that the use of mixture of polyols based on MSA and PLA positively affected the properties of the obtained foam. The polyurethane foam based on this polyol mixture showed good thermal resistance and significantly reduced flammability in comparison with the foam based MSA-polyol. Moreover, it showed higher compressive strength, lower thermal conductivity and biodegradability in soil. The results of the conducted tests confirmed that the new foam was characterized by very good performance properties. In addition, this research provides information on new waste management opportunities and fits into the doctrine of sustainable resource management offered by the circular economy