Effects of crosslinking density on structure and properties of interpenetrating polymer networks from polyurethane and nitroguar gum

In this study, dimer acid (DA) obtained from waste soybean oil was used together with propylene oxide (PO) to obtain novel polyether polyols [prepolymers for polyurethanes (PUs)] through ring‐opening polymerization reaction. The average molecular weight of polyols was estimated by gel permeation chromatography and titration method. The substantial reaction between DA and PO was evident from FTIR and nuclear magnetic resonance spectroscopy. Subsequently, the polyols were reacted with chain extender [ethylene glycol, (EG)] and 4, 4 ‐ Diphenylmethane diisocyanate (MDI) to prepare green PUs. The effect of molar ratio variation of EG and MDI with a fixed amount of polyols was estimated by measuring hydrophobicity and mechanical strength of PUs. The molar ratio such as 1 : 4 : 5.7 of polyol : EG : MDI was found to exhibit maximum hydrophobicity and improved mechanical strength that were comparable with typical PU sample prepared from commercially available polyol, such as polypropylene glycol. FTIR spectroscopic analysis confirmed the chemical changes and possible crosslinking in PUs. Thermalgravimetric analysis and differential scanning calorimetry analysis also showed substantial thermal stability of the green PUs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41410.

Section: Introductionmentioning

confidence: 99%

“…12,13 Vegetable oil has also been blended to prepared polyols as a starting material for Pus. 14,15 Petrovic et al have reported the preparation of rigid type PUs from soybean oil. 16 There are several reports available on the PUs based on soybean oil, castor oil, nahar seed oil, rape seed oil, and plam oil.…”

Section: Introductionmentioning

confidence: 99%

Green polyurethane from dimer acid based polyether polyols: Synthesis and characterization

Saha

Suh

2014

“…Recently, environment‐friendly materials from renewable raw materials such as cellulose, starch, polysaccharides, protein, plant oil, and so forth, have been used to obtain an easily degradable and low toxicity polymer matrix. This can be achieved by the synthesis of synthetic polymers from natural resources or by mixtures of synthetic polymers with natural polymers 2, 14, 15. One of the most frequently used renewable raw materials for polymer applications are plant oils.…”

Section: Introductionmentioning

confidence: 99%

Properties of crosslinked polyurethanes obtained by acrylic side‐group polymerization and of their blends with various plant oils

Oprea¹

2013

Novel polyurethane elastomers have been developed to incorporate plant oil into their matrix. Bisphenol A glycerolate diacrylate was used as a chain extender for the polyurethane prepolymer obtained from poly(tetramethylene oxide) glycol and 1,6hexane diisocyanate. The curing of the polyurethane acrylate matrix in the presence of the plant oil results in a network matrix which includes renewable resources in their structure. The effects of the inclusion of different vegetable oil (such as soybean oil, rapeseed oil, cotton oil, or sunflower oil) into the crosslinked polyurethane acrylates matrix were studied by evaluating various properties of the films such as the thermal behavior, the tensile properties, and the surface properties. The increases in chain extender content determine an increase of the thermal stability (the 10% weight loss decomposition temperatures increase from 325 to 375 C) and mechanical strength (from 3 to 9 MPa). Contact angle measurements have shown that the hydrophobic property of the films surface slightly increased with the incorporation of plant oil into the crosslinked polyurethane matrix. In addition, polyurethane/plant oil blends exhibit enhanced mechanical strength (from 3 to 9.8 MPa), as well as an increased roughness reaching a maximum average (113 nm) in the case of cotton oil. All polyurethane/plant oil blend present higher values for glass transition temperature and slightly enhanced values for thermal stability.

“…Fourier transform infrared spectroscopy can speculate the composition of PU samples according to the specific absorption frequency and thus give qualitative results . On contrast, nuclear magnetic resonance can help to give quantitative results because the molar ratio of hydric groups is available by referring to different hydrogen atom’ chemical shifts in 1 H‐nuclear magnetic resonance spectra . Besides, apart from TGA analysis carrying out in this study, differential scanning calorimetry, and dynamic thermomechanical analysis are two kinds of common thermal analysis.…”

Section: Resultsmentioning

confidence: 99%

Study on the tribological properties of modified polyurethane material for water‐lubricated stern bearing

Jiang

Guo

Yuan

et al. 2018

Polyurethane (PU) has been studied as alternative bearing material for marine water-lubricated stern tube due to its excellent wear resistance, remarkable mechanical properties and so on. In this study, nine types of PU samples which are composed of different additives were prepared and tested in order to investigate their tribological properties under various working conditions. A pin-on-disc tribo-tester was used to conduct tests. Then comparison analyses were conducted from three aspects, including the friction coefficient, wear mass loss, and the wear surface topography. The analysis results showed that: (1) the different additives as well as the mass fraction of these additives lead to significant difference in terms of tribological properties of PU; (2) the lubricating grease, as one of additives, improved the wear resistance and friction performance effectively; (3) modified PU is eligible to work as matrix because of satisfied mechanical properties and specific internal morphology. It is believed that understandings in this study are beneficial to the improvement of the tribological properties of PU and also provide the real practical basis for the studies of polymer materials which applied on waterlubricated marine stern tube bearing.