Color formation in polyurethanes

Beachell, Harold C.; Son, Chu Pham Ngoc

doi:10.1002/app.1963.070070621

Cited by 44 publications

(11 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…200x) of the polyurethane before and after ( Figure 6 curve III(a )-(d )) gamma irradiation treatment indicate that the polyurethane acquires color changes under gamma where it turns to yellow after irradiated in absence of oxygen under vacuum. While if the color of PU turned dark brown it is a probable oxidation of the amine and this indicates the degradation of PU in presence of oxygen [34,35]. The difference in color combined with change in the degree of crosslinking and crystallinity was observed.…”

Section: Effect Of Irradiation Doses On the Morphologicalmentioning

confidence: 99%

Radiation Crosslinking of Polyurethanes: Characterization by FTIR, TGA, SEM, XRD, and Raman Spectroscopy

Ghobashy

Abdeen

2016

Journal of Polymers

View full text Add to dashboard Cite

Gamma radiation can be used for enhancing the physical properties of polyurethane (PU). Radiation was used to crosslink a polyurethane at room temperature; four samples of the PU solid film are irradiated at variable four radiation doses 0, 50, 100, and 150 kGy under vacuum conditions. Crosslinking radiation is more common than oxidative degradation and crosslinking is believed to be more efficient in the soft segment of PU. The structure of the PUs is performed by Fourier transform infrared (FTIR-ATR), Thermogravimetric Analysis (TGA-DTG), and X-ray Diffraction (XRD) which have been used to investigate the effect of gamma radiation on the polyurethane (PU). The results showed that the radiation crosslinking of polyurethanes improved the thermal stability and the crystallinity. The microstructure modifications of polyurethane samples have also been studied as a function of the dose using the scanning electron microscope (SEM). The effects of gamma irradiation on the color changes of polyurethane were observed. The irradiated PUs have conjugated structure and are capable of emitting purple fluorescence.

show abstract

Section: Effect Of Irradiation Doses On the Morphologicalmentioning

confidence: 99%

Radiation Crosslinking of Polyurethanes: Characterization by FTIR, TGA, SEM, XRD, and Raman Spectroscopy

Ghobashy

Abdeen

2016

Journal of Polymers

View full text Add to dashboard Cite

show abstract

“…The decrease of C=0 groups at the earlier stage of irradiation could be attributed to decrease of PUR sequences. However, the increase of the mentioned band at prolonged irradiation after 50 hours is caused by the formation of new oxidized structures (5,8,15,18).…”

Section: Resultsmentioning

confidence: 97%

“…Figure 1 presents the changes in IR spectra of irradiated solutions of polyurethane, PUR. Unexposed PUR shows the absorption bands characterstic of the urethane functional group (8,13,14) these experiments were performed on the isocyanate terminated prepolymer. During the irradiation, the decrease of intensity of absorption bands mentioned above was considerable.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Ultraviolet Degradation of Polyester-Based Polyurethane

Rek

Bravar

1983

Journal of Elastomers & Plastics

View full text Add to dashboard Cite

The structural changes after ageing of polyurethane by UV irradiation has been studied by comparative spectroscopic measurements. The polyurethane was prepared from diphenylmethane-4,4'-diisocyanate, (MDI) and polyester from adipic acid and ethylene glycol. The experimental results show that various oxidized structures are formed in UV degraded samples with simultaneous decomposition of polyurethane. This leads to the formation of new structures such as carbonyl, azo, carbodiimide, quinoid as well as polyene sequences. According to the experimental results and the data taken from the literature, the mechanism of the process was discussed.

show abstract

“…al [4] and Beachell et. al [13] have already reported the changes in IR spectrum of polyurethane caused by photo-degradation.…”

Section: Changes In Flexural Properties After Wom Exposurementioning

confidence: 98%

Thermal and Photo-Degradation Behaviors of Glass-Fiber Reinforced Rigid Polyurethane Foam

Morimoto

Suzuki

Yosomiya

1983

Journal of Composite Materials

View full text Add to dashboard Cite

Thermal and photo-degradation of rigid polyurethane foams (PUF) and glass fiber reinforced rigid polyurethane foams (FRU) have been studied.It was found that FRU and PUF showed the nearly the same degradation behavior for flexural properties. In general, slightly higher degradation was observed with samples of lower expansion ratio, higher apparent density and containing glass fiber of shorter length.Measurement of interlaminar shear strength of heat-treated samples suggested that reduction in this property would be ascribable to the reduction in both the shear modulus of matrix and the bonding strength between matrix and fiber. No significant difference was observed among the types of samples in the degradation behaviors for flexural properties after WOM exposure, but samples of higher apparent density tended to show a slightly higher degradation. IR analysis revealed that some of the urethane linkages contained have been lost after WOM exposure.

show abstract

Color formation in polyurethanes

Cited by 44 publications

References 18 publications

Radiation Crosslinking of Polyurethanes: Characterization by FTIR, TGA, SEM, XRD, and Raman Spectroscopy

Radiation Crosslinking of Polyurethanes: Characterization by FTIR, TGA, SEM, XRD, and Raman Spectroscopy

Ultraviolet Degradation of Polyester-Based Polyurethane

Thermal and Photo-Degradation Behaviors of Glass-Fiber Reinforced Rigid Polyurethane Foam

Contact Info

Product

Resources

About