Synthesis of polyesters containing disiloxane subunits: Structural characterization, kinetics, and an examination of the thermal tolerance of Novozym-435

Frampton, Mark B.; Séguin, Jacqueline P.; Marquardt, Drew; Harroun, Thad A.; Zelisko, Paul M.

doi:10.1016/j.molcatb.2012.09.010

Cited by 20 publications

(19 citation statements)

References 24 publications

(35 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly, Model 2 considers the deactivation of the enzyme (Equation 14), and the main rate equation defined by Equation (16). Furthermore, this model assumes the possibility that the solubility of ibuprofen in the reaction medium increases with the reaction time and temperature, which is established by defining an effective concentration of reactive ibuprofen (C IR0 ) and also including the concentration of ibuprofen monoglyceride (C MG ), due to its capacity to enhance the scarce mutual solubility of ibuprofen and glycerol; the ibuprofen solubility is defined by Equation (17).…”

Section: Kinetic Modellingmentioning

confidence: 99%

“…Novozym ® 435 is a commercially available heterogeneous biocatalyst Candida antarctica lipase B. This enzyme preparation has been used in the esterification of profens such as naproxen [7], ibuprofen [8,9], flurbiprofen [10], and ketoprofen [11] for the synthesis of prodrugs; it has also been used in the production of biodiesel [12][13][14] and in the development of polymerization bioprocesses [15][16][17]. It can actuate when suspended in various solvents and renewable resources such as supercritical carbon dioxide, ionic liquids [18], 2 of 19 glycerol [19][20][21], and deep eutectic solvents (DES), the high viscosity of which, as in the case of glycerol, can be reduced by water addition [22].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Ibuprofen Monoglyceride in Solventless Medium with Novozym®435: Kinetic Analysis

et al. 2020

View full text Add to dashboard Cite

This study investigates the enzymatic esterification of glycerol and ibuprofen in a solventless medium catalyzed by immobilized lipase B from Candida antarctica (Novozym®435). Fixing the concentration of this enzymatic solid preparation at 30 g·L−1, and operating at a constant stirring speed of 720 rpm, the temperature was changed between 50 and 80 °C, while the initial concentration of ibuprofen was studied from 20 to 100 g·L−1. Under these conditions, the resistance of external mass transport can be neglected, as confirmed by the Mears criterion (Me < 0.15). However, the mass transfer limitation inside the pores of the support has been evidenced. The values of the effectiveness factor (η) vary between 0.08 and 0.16 for the particle size range considered according to the Weisz–Prater criteria. Preliminary runs permit us to conclude that the enzyme was deactivated at medium to high temperatures and initial concentration values of ibuprofen. Several phenomenological kinetic models were proposed and fitted to all data available, using physical and statistical criteria to select the most adequate model. The best kinetic model was a reversible sigmoidal model with pseudo-first order with respect to dissolved ibuprofen and order 2 with respect to monoester ibuprofen, assuming the total first-order one-step deactivation of the enzyme, with partial first order for ibuprofen and enzyme activity.

show abstract

Section: Kinetic Modellingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis of Ibuprofen Monoglyceride in Solventless Medium with Novozym®435: Kinetic Analysis

et al. 2020

View full text Add to dashboard Cite

show abstract

“…2d). The characteristic stretching vibration modes of the linear siloxane were located at 1080, 1052, and 1018 cm -1 , which are similar to the absorption peaks of siloxane in polydimethylsiloxane (PDMS) [45][46][47]. Unlike OHIMs consisting of three-dimensional siloxane network, the formed linear siloxane chains allowed the epoxy and amine groups to react with less sterical hindrance.…”

Section: Ftir Studiesmentioning

confidence: 66%

Novel organic–inorganic hybrid materials based on epoxy-functionalized silanes

Sitthiracha

Kilmartin

Edmonds

2015

J Sol-Gel Sci Technol

View full text Add to dashboard Cite

Hybrid materials comprising inorganic glasses and organic polymers were investigated as potential replacements for diglycidyl ether of bisphenol-A to improve the thermomechanical properties of available composites. An epoxy-functionalized silane, 3-glycidoxypropyltrimethoxysilane (GPTMS), was employed to synthesize organic-inorganic hybrid materials (OIHMs) via a sol-gel process. The oxirane ring in GPTMS was cross-linked by compounds including an aliphatic amine, diethylenetriamine, amine-functionalized silane, n-(2-aminoethyl)-3-aminopropyltrimethoxysilane, tertiary amine, 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30), and an acid anhydride, hexahydrophthalic anhydride. OIHMs derived from a difunctional organosilane, (3-glycidoxypropyl)methyldimethoxysilane, were also synthesized to compare the mechanical properties with OIHMs derived from GPTMS. Structural characterization of cured OIHMs was performed using a combination of attenuated total reflectance spectroscopy (FTIR-ATR) and 29 Si solid-state nuclear magnetic resonance. Differential scanning calorimetry and thermogravimetric analysis were used to clarify the thermal properties. The thermomechanical properties and cross-link density were evaluated using dynamic mechanical thermal analysis (DMTA). In this study, it was evident that the presence of inorganic networks provided a significant improvement of the thermomechanical properties, where the glass transition temperature typically increases by 20°C and the storage modulus at 150°C by nearly eight times that of neat epoxy resin. An increase in glass transition temperature, end-use temperature, and the thermomechanical behavior of OIHMs was observed and quantified using DMTA. These results corresponded to calculated increases in cross-link density.

show abstract

“…[93] Some reports determined that the optimal range for carrying out these reactions was in the range of 70-90 8C. [94][95][96] Frampton et al [97] reported the synthesis of siloxane-containing polyesters and polyamides by using immobilized CalB at temperatures that werea bove the denaturation point of the CalB molecule. The siloxane moieties in the monomers conferred ar esistance to thermal degradation to the enzyme that not only permitted its use at elevated temperatures, in some cases as high as 150 8C, but also allowed it to be reused multiple times with only minor loss in catalytic activity.I nl ight of these observations, it was of interestt od etermine the longterm thermalt olerance of as ingle batch of the immobilized enzyme.…”

Section: Thermal Tolerance Of Calb In the Presence Of Siloxanesmentioning

confidence: 99%

“…Attempts to produce these macrolactones by incorporating 1,2cyclohexanediol into the macrocyclic structurew ere unsuccessful. The success of this approach was heavily dependent on the chain length of the ester;atheme that hasbeen reinforced throughout work by Zelisko [83,84,91,97,108,114] on enzymatic polymerizationsofs iloxanes.…”

Section: Chain-length Selectivity By Calbmentioning

confidence: 99%

Biocatalysis in Silicon Chemistry

Frampton

Zelisko

2017

Chemistry An Asian Journal

Self Cite

View full text Add to dashboard Cite

The application of biocatalytic or chemoenzymatic techniquesi ns ilicon chemistry serves two roles:i tp rovides ag reater understanding of the processing of silicon species by natural systems, such as plants, diatoms, and sponges, as well openingu pa venues to green methodologies in the field. In the latter case, biocatalytic approaches have been applied to the synthesis of small-molecule systems and polymeric materials. Often these biocatalytic approaches allow access to molecular structures under mild conditions and, in some cases, molecular structures that are not accessible throught raditional chemical methodologies. Ar eview of recent advances in the applications of biocatalysis in silicon chemistry is presented.

show abstract

Synthesis of polyesters containing disiloxane subunits: Structural characterization, kinetics, and an examination of the thermal tolerance of Novozym-435

Cited by 20 publications

References 24 publications

Synthesis of Ibuprofen Monoglyceride in Solventless Medium with Novozym®435: Kinetic Analysis

Synthesis of Ibuprofen Monoglyceride in Solventless Medium with Novozym®435: Kinetic Analysis

Novel organic–inorganic hybrid materials based on epoxy-functionalized silanes

Biocatalysis in Silicon Chemistry

Contact Info

Product

Resources

About