IR-change and yellowing of polyurethane as a result of UV irradiation

Roşu, Dan; Roşu, Liliana; Caşcaval, Constantin N.

doi:10.1016/j.polymdegradstab.2009.01.013

Cited by 242 publications

(189 citation statements)

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“…For example, the polyurethanes obtained from aromatic isocyanates will turn yellow when exposed to UV radiation. This is due to the oxidation reaction in the polymer backbone [28]. In addition to radiation, the presence of oxygen is an important parameter as it speeds up the aging process of polyurethane materials, eg the initial thermal decomposition temperature in the air is about 50 °C lower than in N 2 [29].…”

Section: Introductionmentioning

confidence: 99%

The Study on Application of Biopolyols Obtained by Cellulose Biomass Liquefaction Performed with Crude Glycerol for the Synthesis of Rigid Polyurethane Foams

et al. 2017

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In this work rigid polyurethane foams (PUR) were obtained by replacement of 0-70 wt% of petrochemical polyol with biopolyol obtained via cellulose liquefaction in presence of crude glycerol. The foams with different content of a bio-polyol were prepared by single step method for NCO/OH ratio equals 1.5. The prepared materials were analyzed in terms of their morphology, chemical structure, thermal stability and basic physical and mechanical properties. The effects of photo-oxidative and thermo-oxidative aging on chemical structure, apparent density and mechanical properties of the biomass based rigid polyurethane foams were investigated and discussed.

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Section: Introductionmentioning

confidence: 99%

The Study on Application of Biopolyols Obtained by Cellulose Biomass Liquefaction Performed with Crude Glycerol for the Synthesis of Rigid Polyurethane Foams

et al. 2017

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“…The hard segments bear a strong influence on the modulus, hardness, and tear strength, while the soft segments impart softness, elasticity, long elongation at break and low-temperature resistance. TPUs with hard segments produced from 1,1 0 -methanediylbis(4-isocyanatobenzene) and butane-1,4-diol (BD) generally possess superior mechanical properties [3], but as aromatic diisocyanate are used, they tend to yellow upon exposure to ultraviolet and visible light as well as heat; that may lead even to their total destruction [2][3][4][5][6][7]. These drawbacks are restrictions to the expansion of their applications in high-quality materials and outdoor functions.…”

Section: Introductionmentioning

confidence: 99%

Transparent sulfur-containing thermoplastic polyurethanes with polyether and polycarbonate soft segments

Rogulska

2017

Polym. Bull.

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New thermoplastic polyether-and polycarbonate-based segmented polyurethanes were synthesized by a catalyzed one-step melt polyaddition from diphenyl sulfide-derivative diol, i.e., 2,2 0 -[sulfanediylbis(benzene-1,4-diyloxy)]diethanol as a nonconventional chain extender, 1,1 0 -methanediylbis(4-isocyanatocyclohexane), and 40, 50, and 60 mol% poly(hexane-1,6-diyl carbonate) diol (PHCD) of M n ¼ 860 g=mol or poly(oxytetramethylene) diol (PTMO) of M n ¼ 1000g=mol as soft segments. The structures and thermal properties of the polymers were examined by FTIR, elemental analysis, differential scanning calorimetry, thermogravimetry (TG), and TG-FTIR. Moreover, their Shore A/D hardness, tensile, physicochemical, adhesive, and optical properties were determined. The obtained colorless, transparent, amorphous materials exhibited elastomeric or plastic properties. The PTMO-based polymers showed lower glass-transition temperatures than those based on PHCD (from -29 to 5°C vs. from 11 to 43°C) as well as a higher degree of microphase separation. On the other hand, the polymers with the polycarbonate soft segments revealed better transparency (transmittance at 800 nm: 84-89% vs. 75-82%), higher tensile strength (up to 48.6 MPa vs. up to 28.3 MPa), and hardness in comparison with those with the polyether soft segments. The polymers decomposed in two (in helium) or three (in air) stages and possessed a relatively good thermal stability. Their temperatures of 1% mass loss were contained within the range of 255-274°C. In inert atmosphere, the values shown by polymers from PTMO were higher than those from PHCD, whereas in oxidative atmosphere, the situation was reversed. The newly synthesized sulfur-containing polymers showed a higher refractive index and adhesive strength to copper than analogous polymers based on butane-1,4-diol as a chain extender.

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“…The peaks at 1605, 1416, 1250, and 1022 cm −1 represent COOasymmetric stretching [28], COO-symmetric stretching [29,30], CH 3 symmetric bending [31], and C-O-C anti-symmetric stretching [32,33], respectively. For C. crispus biomass, the main bands relate to -OH overlapping (3283 cm −1 ) [26], C-H stretching (2924 cm −1 ) [27], C=C stretching (1644 cm −1 ) [34], N-H bending and C-N stretching (1531 cm −1 ) [35], COO− symmetric stretching (1416 cm −1 ) [29,30], S-O stretching (1152 and 1221 cm −1 ) [36,37], C−O−C antisym. stretching (1152 and 1034 cm −1 ) [32,33], and CH bending (696 cm −1 ) [38].…”

Section: Characterizationmentioning

confidence: 99%

A Comparison of Palladium Sorption Using Polyethylenimine Impregnated Alginate-Based and Carrageenan-Based Algal Beads

2018

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Two kinds of algal beads were prepared using a carrageenan-based alga (Chrondrus crispus) and an alginate-based alga (Laminara digitata) ionotropically gelled with K(I) and Ca(II), respectively: the process consists of biopolymer partial extraction followed by hydrogel formation. The beads were modified with branched polyethylenimine (bPEI) and glutaraldehyde (GA) using the impregnation method to improve their sorption capacity for Pd(II) in acid solution. SEM-EDX and FTIR techniques were used for characterizing the beads. The impacts of pH and presence of anions, cations, and Pt(IV) were studied in batch experiments. The beads were also applied for Pd(II) recovery from synthesized leaching liquors of a spent catalyst and a car catalytic converter via the sorption-desorption process. Results show that Pd is concentrated in the outer layer of L. digitata-bPEI-GA composite (LD/PEI) beads, while in the case of the C. crispus-bPEI-GA composite (CC/PEI), it is homogenously distributed in the whole mass of the sorbents. The difference is attributed to the repulsive force of the outer Ca(II)-alginate barrier of LD/PEI beads that makes it difficult for the branched polymer PEI to penetrate through the layer and be immobilized in the inner compartment. As a result, LD/PEI beads possess a lower maximum sorption capacity, but a slightly faster uptake at pH 1 than CC/PEI beads. In addition, CC/PEI beads present a better recovery performance compared to LD/PEI beads when applied for the treatment of synthesized leaching liquors.

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IR-change and yellowing of polyurethane as a result of UV irradiation

Cited by 242 publications

References 10 publications

The Study on Application of Biopolyols Obtained by Cellulose Biomass Liquefaction Performed with Crude Glycerol for the Synthesis of Rigid Polyurethane Foams

The Study on Application of Biopolyols Obtained by Cellulose Biomass Liquefaction Performed with Crude Glycerol for the Synthesis of Rigid Polyurethane Foams

Transparent sulfur-containing thermoplastic polyurethanes with polyether and polycarbonate soft segments

A Comparison of Palladium Sorption Using Polyethylenimine Impregnated Alginate-Based and Carrageenan-Based Algal Beads

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