A One-pot Multicomponent Reaction for the Synthesis of Oligoetherols with Azacyclic Rings

Lubczak, Jacek; Lubczak, Renata; Zarzyka, Iwona

doi:10.17344/acsi.2017.3495

Cited by 3 publications

(5 citation statements)

References 6 publications

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“…General conclusion from our previous and current results are as follows: PUFs obtained from polyols derived from chitosan have apparent density within 50.5–70 kg m −3 . PUFs obtained from polyols based on chitosans from high molecular weight chitosan have low water uptake (usually 1.9%–3.9% after 24 h exposure). Low heat conductance coefficient is characteristic for PUF obtained from chitosans of low, medium, and high molecular weight. 4. PUFs obtained from polyols (vide supra) derived from chitosans have higher thermal resistance then traditional PUFs 46 and slightly higher than foams obtained from oligomeric or water soluble chitosans. Compressive strength of obtained foams is typical for rigid foams. The foams obtained from chitosans of high molecular weight have the highest compression strength due to rigid structural chain elements in the PUF. Annealing of PUFs based on chitosans at 150°C results in increase of compressive strength.…”

Section: Resultsmentioning

confidence: 99%

Polyols and polyurethane foams based on chitosans of various molecular weights

Strzałka,

Dębska,

Lubczak

2024

J of Applied Polymer Sci

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Shrinking resources of fossil oil prompt search for other biosphere‐present substrates to obtain polyols, which in turn are basic components to synthesize polyurethane foams (PUF). Widely available examples are biopolymers like starch, cellulose, and chitosan. It has been shown that oligomeric chitosan as well as water soluble chitosan can be applied to obtain polyols and rigid PUF of good performance properties. In this paper, the higher molecular mass chitosans, insoluble in organic solvents and water, were converted to polyols and ultimately into foamed polyurethane plastics. The polyols were characterized by the infrared spectra (IR), 1H‐NMR, and MALDI‐ToF methods. Their properties, such as density, viscosity, surface tension and hydroxyl numbers, were determined. The PUF were obtained from these polyols of various molecular mass. The biodegradable, rigid PUF of enhanced thermal resistance were obtained. Their physical parameters like apparent density, water volume absorption, dimension stability, heat conductance, compressive strength, and heat resistance at 150 and 175°C were studied and compared with those synthesized previously from oligomeric chitosan and water soluble chitosan.

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Section: Resultsmentioning

confidence: 99%

Polyols and polyurethane foams based on chitosans of various molecular weights

Strzałka,

Dębska,

Lubczak

2024

J of Applied Polymer Sci

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“…Pianki o zwiększonej odporności termicznej można uzyskać stosując do reakcji z wielofunkcyjnymi izocyjanianami oligoeterol otrzymywany w prosty sposób w reakcjach węglanów alkilenowych, a szczególnie węglanu propylenu (WP), z tanim i łatwo dostępnym surowcem, jakim jest melamina (Mel). Reakcje melaminy z węglanem propylenu zostały opisane w pracy [6]. Prowadzi się je w temperaturze 175-180 o C w ciągu 8 godzin, przy wyjściowym stosunku molowym Mel : WP = 1 : 20:…”

Section: Wprowadzenieunclassified

“…Oligoeterol z pierścieniem 1,3,5-triazynowym otrzymano przy wyjściowym stosunku molowym Mel : WP = 1 : 20 wg przepisu podanego w pracy [6]. Syntezę oligoeterolu z kwasu metakrzemowego (H 2 SiO 3 ), glicydolu i węglanu etylenu wykonano wg [12].…”

Section: Część Doświadczalna 21 Syntezyunclassified

“…Po dokładnym wymieszaniu składników wprowadzano obliczoną wstępnie ilość polimerycznego diizocyjanianu difenylometanu (zawierającego ok. 30% mas izocyjanianów trójfuncyjnych, cz. MERCK, Niemcy) w oparciu o ilości stosowane do uzyskania pianek z oligoeteroli otrzymanych odpowiednio z kwasu krzemowego i melaminy [6,12]. Składniki mieszano energicznie do momentu rozpoczęcia kremowania.…”

Section: Otrzymywanie Pianek Poliuretanowychunclassified

“…Oznaczona liczba hydroksylowa uzyskanej mieszaniny wynosi 545,3 mg KOH/g, podczas gdy obliczona na podstawie składu jest równa 392,3 mg KOH/g. Te różnice wynikają z obecności glikoli i poliglikoli tworzących się jako produkty uboczne zarówno w oligoeterolu otrzymywanym z melaminy [6] jak i z kwasu metakrzemowego [12]. Przeprowadzono próby zastosowania uzyskanego oligoeterolu do otrzymywania pianek poliuretanowych.…”

Section: Analiza I Omówienie Wynikówunclassified

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Pianki Poliuretanowe Z Pierścieniem 1,3,5-Triazynowym I Atomami Krzemu

Chmiel

Barcikowska²,

Lubczak

2017

CT&B

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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

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Prins-Friedel-Crafts Cyclization: Synthesis of Diversely Functionalized Six- Membered Oxacycles

Roy¹

2021

COC

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: Prins cyclization is a well-established synthetic protocol to generate a wide range of important oxygen heterocycles. It is a cyclization reaction performed by an oxocarbenium ion that undergoes an intramolecular pi-bond attack to construct a new carbon-carbon bond. When this cyclization process is conjugated with Friedel-Crafts reaction, it further expands the synthetic potential by fabricating two different carbon-carbon bonds in one single reaction. Different acid catalysts mediated, the coupled Prins-Friedel-Crafts reaction is conducted both in stepwise as well as in tandem fashion. In the stepwise route, three different reacting components were utilized whereas, the tandem methodology required proper modification of the initial substrate molecule. An array of allylic, propargylic, other related alkenols, and carbonyl reactants were employed to carry out the cyclization process. Several oxygenated heterocycles equipped with diverse functionalities were constructed in a stereoselective manner which again reinforced the significance of this cyclization protocol undoubtedly. The present mini-review highlights (on) the utilization of different one-pot stepwise Prins-Friedel-Crafts reactions and the subsequent development of cascade Prins-Friedel-Crafts cyclization process to furnish intricate molecular architectures of vital six-membered oxacycles.

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A One-pot Multicomponent Reaction for the Synthesis of Oligoetherols with Azacyclic Rings

Cited by 3 publications

References 6 publications

Polyols and polyurethane foams based on chitosans of various molecular weights

Polyols and polyurethane foams based on chitosans of various molecular weights

Pianki Poliuretanowe Z Pierścieniem 1,3,5-Triazynowym I Atomami Krzemu

Prins-Friedel-Crafts Cyclization: Synthesis of Diversely Functionalized Six- Membered Oxacycles

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