Synthesis and Thermo‐Mechanical Properties of Poly(urethaneurea) Elastomers Based on Heterocyclic Cross‐linkers and Purine Diamine as a Chain Extender

Oprea, Stefan; Potolinca, Violeta Otilia

doi:10.1002/adv.21532

Cited by 7 publications

(2 citation statements)

References 19 publications

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“…24 TGA data show that SPDA-based PUs exhibit better thermal stability than conventional PU chain extended with butanediol. 25 This improved thermal stability is due to the presence of SPDA moieties in the main chains.…”

Section: Resultsmentioning

confidence: 99%

Structure–properties relationship of the polyurethanes that contain Schiff base in the main chain

Oprea¹,

Potolinca²,

Oprea

et al. 2020

High Performance Polymers

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This article studies the diversification of useful properties of polyurethane (PU) structures by the inclusion of new components. PUs containing a Schiff base in the main chain were synthesized by using N, N′-bis(salicylidene)-1,3-propanediamine as a chain extender. Novel Schiff base PUs were synthesized via a two-step polymerization starting from a Schiff base derivative diol chain extender with different molar ratios or by cross-linking with various natural raw materials. The sought after structures was confirmed by Fourier transform infrared spectra that showed the disappearance of the signals of both the hydroxyl and isocyanate groups. The thermal properties of these PUs were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The initial degradation temperatures of the obtained PUs were found to be in the range of 300–350°C. Based on the results from DMA, the rigid structure of the Schiff base from the backbone of the PUs presented a higher storage modulus, results which may be connected to the physical cross-linking process of the macromolecules. Their optical properties were determined by fluorescence spectroscopy. The incorporation of Schiff base structures into the main PU chain generates new PU structures with improved thermomechanical properties, which includes possible bioactive Schiff base moieties, widening the range of practical applications for such polymers.

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Section: Resultsmentioning

confidence: 99%

Structure–properties relationship of the polyurethanes that contain Schiff base in the main chain

Oprea¹,

Potolinca²,

Oprea

et al. 2020

High Performance Polymers

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show abstract

“…Additionally, diamine as chain-extender produces urea groups which have higher capacity to form hydrogen bonds, which increase the stability of the polyurethane urea materials. 17-19 The fact that polyurethanes exhibit poor thermal stability justifies the need to find new polyurethane compositions which include thermally stable groups such as pyrimidine, 20 isosorbide, 21 purine, 22 or pyridazine. 23…”

Section: Introductionmentioning

confidence: 99%

The effects of the inclusion of 1,2,4-triazole derivatives into the main chains of the polyurethane urea exposed to UV radiation

Oprea¹,

Potolinca²

2021

High Performance Polymers

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Linear polyurethane urea containing 1,2,4-triazole segments was obtained by polyaddition of the 3,5-diamino-1,2,4-triazole (DATA) to urethane prepolymer. Also, three crosslinked polymers with different crosslinkers (2,4,6-triaminopyrimidine (TAP), glycerin (Gly), castor oil (CO)) were synthesized. Thermogravimetric analysis, of the obtained polymers, indicated good thermal stability up to 310°C. The polyurethane urea chemical structure was confirmed by FTIR analysis. The glass transition temperatures (Tg) of these polymers, measured by differential scanning calorimetry (DSC), were found in the range of −52°C to −56°C. These values were not significantly influenced by the structure of the hard domain and the intermolecular interactions. The tensile testing showed that the inclusion of 1,2,4-triazole in polyurethane structure substantially improves the tensile strength up to 58 MPa. The obtained polyurethane urea presents surface slight hydrophobic and low interfacial tension. The positive effect of the 1,2,4-triazole segment from the polymer main chain in the UV aging process of these polymer materials has been studied. After exposure to UV radiation, few changes were observed in the molecular structure, in the surface morphology and the mechanical properties.

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Preparation of Polyurethane‐Urea Elastomers Using Low Molecular Weight Aliphatic Diamines Enabled by Reversible CO₂ Chemistry

Zhang

Tian

et al. 2020

Macro Chemistry & Physics

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The use of low molecular weight (LMw) aliphatic diamines for the synthesis of polyurethane‐urea elastomers (PUUEs) is an effective method for introducing abundant, strong hydrogen bonds with the aim of improving the thermal and mechanical properties of PUUEs. However, the reaction between isocyanates and LMw aliphatic diamines is too rapid to produce PUUEs. In this study, PUUEs incorporating LMw aliphatic diamines as chain extenders are prepared via the reversible reaction of CO2 with diamines. The phase separation, thermal properties, and thermomechanical and mechanical properties of polyurethane materials are investigated as the chain extender changed from diol to diamine. Replacing the diol chain extenders with diamine results in the formation of more abundant and stronger hydrogen bonds in PUUEs, which enables the assembly of long range ordered structures and improved microphase separation. The tensile strengths of PUUEs, from 8.4 to 13 MPa, are much higher than their corresponding polyurethanes, owing to the physical crosslinks formed by the more and stronger hydrogen bonds in the PUUEs.

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Synthesis and Thermo‐Mechanical Properties of Poly(urethaneurea) Elastomers Based on Heterocyclic Cross‐linkers and Purine Diamine as a Chain Extender

Cited by 7 publications

References 19 publications

Structure–properties relationship of the polyurethanes that contain Schiff base in the main chain

Structure–properties relationship of the polyurethanes that contain Schiff base in the main chain

The effects of the inclusion of 1,2,4-triazole derivatives into the main chains of the polyurethane urea exposed to UV radiation

Preparation of Polyurethane‐Urea Elastomers Using Low Molecular Weight Aliphatic Diamines Enabled by Reversible CO₂ Chemistry

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Synthesis and Thermo‐Mechanical Properties of Poly(urethaneurea) Elastomers Based on Heterocyclic Cross‐linkers and Purine Diamine as a Chain Extender

Cited by 7 publications

References 19 publications

Structure–properties relationship of the polyurethanes that contain Schiff base in the main chain

Structure–properties relationship of the polyurethanes that contain Schiff base in the main chain

The effects of the inclusion of 1,2,4-triazole derivatives into the main chains of the polyurethane urea exposed to UV radiation

Preparation of Polyurethane‐Urea Elastomers Using Low Molecular Weight Aliphatic Diamines Enabled by Reversible CO2 Chemistry

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Product

Resources

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Preparation of Polyurethane‐Urea Elastomers Using Low Molecular Weight Aliphatic Diamines Enabled by Reversible CO₂ Chemistry