Thermal stability of some cryogels based on poly(vinyl alcohol) and cellulose

Varganici, Cristian–Dragos; Paduraru, Oana Maria; Roşu, Liliana; Roşu, Dan; Simionescu, Bogdan C.

doi:10.1016/j.jaap.2013.09.004

Cited by 18 publications

(7 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The best-fitted degradation mechanisms for the normalized u vector curves and their associated parameters are given in Table 4. The activation energy values for the two steps are in close consistency with those reported recently [34]. For the first (or the major) process, the fitted reaction mechanisms was A 3 (3-D nucleation model from the acceleratory group).…”

Section: Kinetic Parameters For Pva(98)supporting

confidence: 89%

Kinetic analysis of the complex process of poly(vinyl alcohol) pyrolysis using a new coupled peak deconvolution method

Taghizadeh

Yeganeh

Rezaei

2014

J Therm Anal Calorim

View full text Add to dashboard Cite

A peak deconvolution procedure used for the analysis of data corresponding to simultaneous overlapping processes begins with separation of individual processes using functions such as Gaussian, Lorentzian, Weibull, and Fraser-Suzuki (FS) followed by application of kinetic analysis methods to the separated peaks. We propose a coupled peak deconvolution procedure to link the parameters of the FS functions of similar peaks in two DTG curves obtained at different linear heating rates, so that the coordinates of each peak can be obtained in a constrained manner. The proposed technique is a kinetic deconvolution method rather than a pure mathematical deconvolution technique. To analyze individual peaks in our study, the non-parametric kinetic and Freidman's isoconversional methods have been applied to determine kinetic triplet of each process. This technique has been tested with both simulated and experimental data. Using this technique, the effects of molecular weight and degree of hydrolysis of polyvinyl alcohol (PVA) samples on reaction mechanism and activation energy of thermal degradation were studied. The presence of acetate group in the PVA samples causes thermal stability, decreases the rate of main reactions, and increases the activation energy. The results of this study may help tailor heat-resistant materials with proper choice of polymer characteristics.

show abstract

Section: Kinetic Parameters For Pva(98)supporting

confidence: 89%

Kinetic analysis of the complex process of poly(vinyl alcohol) pyrolysis using a new coupled peak deconvolution method

Taghizadeh

Yeganeh

Rezaei

2014

J Therm Anal Calorim

View full text Add to dashboard Cite

show abstract

“…These methods use shifts in thermograms with heating rate increase, due to temperature delay as a function of heating rate [26][27][28][29][30][31].…”

Section: Thermal Decomposition Kineticsmentioning

confidence: 99%

TGA/DTA–FTIR–MS coupling as analytical tool for confirming inclusion complexes occurrence in supramolecular host–guest architectures

Varganici¹,

Marangoci²,

Roşu³

et al. 2015

Journal of Analytical and Applied Pyrolysis

Self Cite

View full text Add to dashboard Cite

“…Polyvinyl alcohol (PVA) is a water‐soluble, odorless, nontoxic, nonionic biodegradable, biocompatible synthetic polymer produced in large scale around the world with many interesting characteristics including excellent film forming, emulsifying, and adhesive properties, resistant to oil and grease, minimal cell, and protein adhesion property . PVA exhibits a strong hydrophilic and hydrogen bonding characteristic due to its hydroxyl groups, thus it is able to form cross linked hydrogels . Polyvinyl alcohol as a polymer with side groups has also been used to prepare conjugated polymers such as polyacetylene (PA) which are types of polymers with long conjugated double bonds and have spectacular properties and used in the areas of optical, electrical, magnetic and, in recent years, photo‐catalysis fields …”

Section: Introductionmentioning

confidence: 99%

The investigation of thermal decomposition pathway and products of poly(vinyl alcohol) by TG‐FTIR

Taghizadeh

Yeganeh

Rezaei

2015

J of Applied Polymer Sci

View full text Add to dashboard Cite

A generalized form of a semiquantitative method has been developed based on the multilinear least-squares regression technique applied on the entire FTIR absorbance spectrum of a gaseous mixture to determine components concentration. Thermal degradation of poly(vinyl alcohol) samples with high, PVA(98), and low degree of hydrolysis, PVA(80), has been investigated by TG-FTIR simultaneous analysis performed in an inert atmosphere. Analysis of gaseous products was carried out using a routine developed in Matlab and this routine returns the product concentration with a reasonable RMS error. The correlation coefficients of the original mixture spectrum with the mixed output were obtained at some specific peak temperatures using irAnalysis software. The first process is the loss of physically adsorbed water which followed by two main processes of thermal degradation. In spite of the similarity of evolved gaseous products, two samples showed some differences in components concentrations identified in the volatile mixture. Acetaldehyde has been identified as the main volatile product in the first thermal degradation step of PVA(98) and PVA(80). The second major degradation product of PVA(80) is acetic acid due to presence of more residual acetate group while 2-butenal have been identified for PVA(98). Water was mainly produced in the first stage of thermal degradation of PVA(98) while it was identified in the first and second stages for PVA(80). This might be attributed to existence of a competition between water and residual acetate group for elimination that postpones the complete elimination of OH group to the second degradation stage.

show abstract

Thermal stability of some cryogels based on poly(vinyl alcohol) and cellulose

Cited by 18 publications

References 29 publications

Kinetic analysis of the complex process of poly(vinyl alcohol) pyrolysis using a new coupled peak deconvolution method

Kinetic analysis of the complex process of poly(vinyl alcohol) pyrolysis using a new coupled peak deconvolution method

TGA/DTA–FTIR–MS coupling as analytical tool for confirming inclusion complexes occurrence in supramolecular host–guest architectures

The investigation of thermal decomposition pathway and products of poly(vinyl alcohol) by TG‐FTIR

Contact Info

Product

Resources

About