Effect of Soy Protein on Kinetics of Polyurethane Formation

2010 ◽  
Vol 160-162 ◽  
pp. 1712-1715
Author(s):  
Guang Heng Wang
Keyword(s):  
Soy Protein ◽  
Soy Protein Isolate ◽  
Kissinger Method ◽  
Toluene Diisocyanate ◽  
Polymerization Reaction ◽  
Dibutyltin Dilaurate ◽  
Ozawa Method ◽  
Scanning Calorimetry ◽  
Model Free ◽  
Kinetics Of

The polymerization reaction kinetics of biodegradable polyurethane extended with soy protein isolate (SPI) with dibutyltin dilaurate (DBTDL) as the curing catalyst was studied by means of non-isothermal differential scanning calorimetry (DSC). Model-free methods, Kissinger method and Ozawa method, were applied for analyzing the DSC data. The Ea and lnA obtained from Kissinger method for catalyzed reaction between toluene diisocyanate (TDI) and Polyoxypropyleneglycol (PPG) are 60.80 kJ•mol-1 and 12.09, and for catalyzed reaction among TDI, PPG, and SPI they were 65.91 kJ•mol-1and 14.04. Similarly the Ea obtained from Ozawa method for catalyzed reaction between TDI and PPG and catalyzed reaction among TDI, PPG, and SPI were 63.49 kJ•mol-1 and 64.78 kJ•mol-1, respectively. The results showed that, the incorporation of a small amount of SPI into polyurethane did not affect the reaction kinetic strongly, but increases the reaction activation energy Ea and lnA.

Investigating the relationship between tack and degree of conversion in DGEBA-based epoxy resin cured with dicyandiamide and diuron

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Kuliaei ◽  
Iraj Amiri Amraei ◽  
Seyed Rasoul Mousavi
Keyword(s):  
Epoxy Resin ◽  
Reaction Order ◽  
Theoretical Data ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Degree Of Conversion ◽  
Ozawa Method ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Kinetics Of

Abstract The purpose behind this research was to determine the optimum formulation and investigate the cure kinetics of a diglycidyl ether of bisphenol-A (DGEBA)-based epoxy resin cured by dicyandiamide and diuron for use in prepregs. First, all formulations were examined by the tensile test, and then, the specimens with higher mechanical properties were further investigated by viscometry and tack tests. The cure kinetics of the best formulation (based on tack test) in nonisothermal mode was investigated using differential scanning calorimetry at different heating rates. Kissinger and Ozawa method was used for determining the kinetic parameters of the curing process. The activation energy obtained by this method was 71.43 kJ/mol. The heating rate had no significant effect on the reaction order and the total reaction order was approximately constant ( m + n ≅ 2.1 $m+n\cong 2.1$ ). By comparing the experimental data and the theoretical data obtained by Kissinger and Ozawa method, a good agreement was seen between them. By increasing the degree of conversion, the viscosity decreased; as the degree of conversion increased, so did the slope of viscosity. The results of the tack test also indicated that the highest tack could be obtained with 25% progress of curing.

scholarly journals Property of poly(hydroxybutyrate) complexed polymer with soy protein isolate using glycerol as a medium

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiaolu Ma, ◽  
Guoxiang Cheng
Keyword(s):  
Water Absorption ◽  
Soy Protein ◽  
Fracture Stress ◽  
Absorption Rate ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Medium Effect ◽  
Scanning Calorimetry ◽  
Fracture Elongation ◽  
Dsc Curves

AbstractA kind of poly(hydroxybutyrate) complexed polymer with soy protein isolate (PcSg) was prepared using glycerol as a medium. Effect of content of SPI on thermal, mechanical properties and water absorption of the PcSg polymer was investigated. The results indicated that SPI not only is miscible with PHB, but also may improve tenacity. The PcSg polymer displayed single glass transition ranges on their differential scanning calorimetry (DSC) curves. The fracture stress and Yang’s modulus of the PcSg increased with PHB concentration, but fracture elongation declined. Water absorption of the PcSg was estimated by water absorption rate of the polymers. By the ratio of hydrophobic PHB and hydrophilic SPI, water absorption of the PcSg was efficaciously modified. It was proposed that the effect on the PcSg mainly was because of intermolecular interactions between PHB and SPI.

REACTION KINETICS OF HEXAMETHYLENE DIISOCYANATE AND POLYPROPYLENE GLYCOLS

2014 ◽  
Vol 87 (4) ◽  
pp. 617-628
Author(s):  
Min-Tzung Ye ◽  
Shinn-Gwo Hong
Keyword(s):  
Reaction Kinetics ◽  
Frequency Factor ◽  
Mechanical Analysis ◽  
Hexamethylene Diisocyanate ◽  
Empirical Equations ◽  
Ozawa Method ◽  
Scanning Calorimetry ◽  
Isothermal Reaction ◽  
Molecular Weights ◽  
Kinetics Of

ABSTRACT The kinetics of the reaction between hexamethylene diisocyanate (HDI) and polypropylene glycols (PPG) of different molecular weights toward the synthesis of polyurethanes with versatile properties was studied using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). From the dynamic exotherms observed in DSC, it was found that the Kissinger equation modified by an additional temperature term in its frequency factor term was able to accurately describe the isothermal reaction kinetics of all HDI/PPG reactions. The modification can be justified by analyses with the Ozawa method and the modulus observed under DMA measurements. Regardless of the type of PPG used, the frequency factors changed with respect to the degree of conversion and maximized at near 70% conversion. The derivation of the modified kinetic equation is presented. In addition, the empirical equations describing the dependence of the activation energies and frequency factors on the molecular weights of PPG were also derived.

Effect of Beeswax on Functional and Structural Properties of Soy Protein Isolate Films

2010 ◽  
Vol 150-151 ◽  
pp. 1396-1399 ◽  
Author(s):  
Xi Hong Li ◽  
Kuan Guo ◽  
Xiao Yan Zhao
Keyword(s):  
Water Vapor ◽  
Structural Properties ◽  
Soy Protein ◽  
Oxygen Permeability ◽  
Soy Protein Isolate ◽  
Water Vapor Permeability ◽  
Protein Isolate ◽  
Vapor Permeability ◽  
Scanning Calorimetry ◽  
Elongation At Break

This paper explains and demonstrates the effects of beeswax on functional and structural properties of soy protein isolate films, containing different glycerol. The results showed that percentage elongation at break, water vapor permeability, and transparency of soy protein isolate films decreased when the beeswax content increased, but tensile strength and oxygen permeability increased. The higher the glycerol content, the higher the film water vapor permeability, oxygen permeability, and transparency. The results of differential scanning calorimetry and Fourier transform infrared spectroscopy suggested that beeswax cross-linked with soy protein isolate molecules via connecting with glycerol, composed the film matrix.

Starch digestion kinetics of extruded reformed rice is changed in different ways with added protein or fiber

2019 ◽  
Vol 10 (8) ◽  
pp. 4577-4583 ◽  
Author(s):  
Kuenchan Na-Nakorn ◽  
Thanawit Kulrattanarak ◽  
Bruce R. Hamaker ◽  
Sunanta Tongta
Keyword(s):  
Soy Protein ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Starch Digestion ◽  
Two Phase ◽  
Corn Bran ◽  
Digestion Kinetics ◽  
Kinetics Of

Extruded rice with added 20% soy protein isolate or corn bran showed two-phase [(k1/k2) high/low, low/high] kinetic patterns.

scholarly journals Kissinger Method in Kinetics of Materials: Things to Beware and Be Aware of

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2813 ◽  
Author(s):  
Sergey Vyazovkin
Keyword(s):  
Activation Energy ◽  
Isoconversional Methods ◽  
Single Step ◽  
Order Reaction ◽  
Kissinger Method ◽  
Scanning Calorimetry ◽  
First Order ◽  
Kinetics Of ◽  
Final Equation ◽  
Derivative Thermogravimetry

The Kissinger method is an overwhelmingly popular way of estimating the activation energy of thermally stimulated processes studied by differential scanning calorimetry (DSC), differential thermal analysis (DTA), and derivative thermogravimetry (DTG). The simplicity of its use is offset considerably by the number of problems that result from underlying assumptions. The assumption of a first-order reaction introduces a certain evaluation error that may become very large when applying temperature programs other than linear heating. The assumption of heating is embedded in the final equation that makes the method inapplicable to any data obtained on cooling. The method yields a single activation energy in agreement with the assumption of single-step kinetics that creates a problem with the majority of applications. This is illustrated by applying the Kissinger method to some chemical reactions, crystallization, glass transition, and melting. In the cases when the isoconversional activation energy varies significantly, the Kissinger plots tend to be almost perfectly linear that means the method fails to detect the inherent complexity of the processes. It is stressed that the Kissinger method is never the best choice when one is looking for insights into the processes kinetics. Comparably simple isoconversional methods offer an insightful alternative.

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