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Polyols for Polyurethane Production
Published in Eric J. Goethals, Telechelic Polymers: Synthesis and Applications, 2018
David J. Sparrow, David Thorpe
The hydroxyl-value or hydroxyl-number determination is an end-group analysis, which is a quantification of the concentration of hydroxyl groups per unit weight of polyol. It is needed to calculate the quantity of isocyanate required for polyurethane production and is in many cases the only guide that is available to the equivalent weight of the polyol. Hydroxyl value is expressed in the units of mg KOH/g, and is related to molecular weight by the following formula (Equation 12): () molecularweight=56.1×functionalityhydroxylvalue(mgKOH/g)×1000
Study on the dispersion, adsorption and early hydration behavior of cement pastes containing multi-armed polycarboxylate superplasticizers
Published in Journal of Dispersion Science and Technology, 2020
Kun Wang, Hao Pang, Hao Huang, Linxia Song, Jianheng Huang, Yangyang Zhao
Where X1 denotes the hydroxyl value (mg KOH/g), X2 represents the acid value (mg KOH/g), c corresponds to the KOH concentration (mol/L), and m denotes the weight of the sample (g). Meanwhile, V1 denotes the volume of the KOH solution in the titration (mL), V2 represents the volume of KOH solution consumed during a blank test. V3 denotes the KOH-ethanol solution dosage (mL) in blank test, and V4 is the volume of KOH-ethanol consumed in the titration of samples (mL). Additionally, the value 56.10 corresponds to the molecular weight of KOH; X1/56.1 equals to the molar amount of hydroxyl per kilogram of samples after reaction; n refers to the molar amount of hydroxyl of samples before reaction. Through these tests and calculations, the polyol esterification rates were determined and are shown in Table 3.
Development of wood protective polyurethane coatings from mahua oil-based polyetheramide polyol: a renewable approach
Published in Soft Materials, 2018
Ashish J. Raychura, Smita Jauhari, Bharatkumar Z. Dholakiya
Polyetheramide polyol was synthesized by reaction of MFA with DGEBA in the presence of triethylamine (TEA) as a catalyst (Fig. 2). In a typical synthesis process, the reaction between MFA (0.2 mol) and DGEBA (0.1 mol) was carried out under refluxing condition for 6 h using 1,4-dioxane as a solvent in a three-necked flask equipped with mechanical stirrer and reflux condenser. The obtained product polyetheramide polyol showed good solubility in common organic solvents such as chloroform, acetone, and xylene. The synthesized polyetheamide was characterized by various physicochemical properties such as hydroxyl value and acid value. The structure of polyetheramide polyol was further confirmed by analytical characterization technique such as Attenuated total reflection fourier transform infrared (ATR-FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy, and molecular weight was determined by the gel permeable chromatography (GPC).
Eco-friendly synthesis of PET-based polymeric plasticiser and its application in nitrile-PVC rubber blends
Published in Indian Chemical Engineer, 2019
Sidhharth Sirohi, Saiyam Dobhal, Manav Doshi, Ratyakshi Nain, Krishna Dutt, Balaram Pani
Figure 1 and Table S1 show acid values and hydroxyl values of reaction mixture withdrawn at different intervals. The ester groups of PET waste react with the hydroxyl group of 1-deconol with time. This reaction leads to conversion of PET waste into polymeric plasticiser and hence decrease in the acid value and hydroxyl value of reaction mixture was observed. The weight loss (%) of polymeric plasticiser and DOP was found to be 2.10 and 4.35, respectively. It was found that polymeric plasticiser had low volatile loss as compared to conventional plasticiser. The smaller weight loss (%) of synthesised polymeric plasticiser indicates better efficiency and environmental safety.