scholarly journals Radical copolymerization of styrene and acrylonitrile in the presence of oligooxyethylene azoester

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Ewa Wiśniewska ◽  
Barbara Pabin–Szafko
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Free Radical ◽  
Radical Copolymerization ◽  
Copolymer Composition ◽  
Hydroxyl Groups ◽  
Reactivity Ratios ◽  
Scanning Calorimetry ◽  
Free Radical Copolymerization ◽  
Glass Transition Temperatures

AbstractTelechelic vinyl oligomers terminated with hydroxyl groups were prepared by free radical copolymerization of styrene (S) and acrylonitrile (AN), initiated by azoester-2,2’-azobis[2-methyl-ω-hydroxy-oligo(oxyethylene) propionate] [AIB-OOE(400)], carried out in N,N-dimethylformamide. The reactivity ratios rS=0,225 and rAN=0,722 for styrene and acrylonitrile, respectively, were evaluated by Kelen-Tüdős method. The glass transition temperatures (Tg) of the copolymers were determined by differential scanning calorimetry. Tg values varied with the copolymer composition in the range of 60-82 °C and the maximum Tg value was obtained for copolymer with 60 mol% AN.

Terpolymerization of Methacrylonitrile, Styrene, and α-Methylstyrene

1972 ◽  
Vol 50 (11) ◽  
pp. 1757-1766 ◽  
Author(s):  
Alfred Rudin ◽  
Schumann S. M. Chiang ◽  
H. Kirk Johnston ◽  
Paul D. Paulin
Keyword(s):  
Free Radical ◽  
Simple Model ◽  
Radical Copolymerization ◽  
Polymer Composition ◽  
Copolymer Composition ◽  
Reactivity Ratios ◽  
Free Radical Copolymerization ◽  
Feed Composition ◽  
Chromatographic Techniques ◽  
Ceiling Temperature

The free radical copolymerization of methacrylonitrile, styrene, and α-methylstyrene was studied at 60 °C in toluene solution. Copolymer composition was calculated from the composition of the unreacted monomers, as measured by g.l.c. Reactivity ratios measured previously for the three monomer pairs involved were used with the simple terpolymerization equation to predict polymer composition. Agreement between predicted and experimental polymer compositions was satisfactory. The behavior of α-methylstyrene can be described by a simple model without reference to ceiling temperature or penultimate effects because sequence lengths of this monomer in the terpolymers are short.A true azeotropic feed composition was not investigated, but several monomer mixtures produced copolymers with compositions which varied so little from that of the feed that the systems could be considered to be azeotropic for practical synthetic purposes. This behavior is in accord with expectations.Analytical accuracy of the gas chromatographic techniques was examined and means are suggested to make the best use of this method in copolymerization studies.

Glass Transition Behavior of Polyisoprene: The Influence of Molecular Weight, Terminal Hydroxy Groups, Microstructure, and Chain Branching

1982 ◽  
Vol 55 (1) ◽  
pp. 245-252 ◽  
Author(s):  
C. Kow ◽  
M. Morton ◽  
L. J. Fetters ◽  
N. Hadjichristidis
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Low Molecular Weight ◽  
Hydroxyl Groups ◽  
Transition Temperatures ◽  
Scanning Calorimetry ◽  
Chain Branching ◽  
Glass Transition Temperatures ◽  
Hydroxy Groups

Abstract The glass transition temperatures for a series of high-1,4 linear and star-branched polyisoprenes have been measured by differential scanning calorimetry. The Fox-Flory relation for the linear polyisoprenes was found to be Tg=Tg∞−1.76×104Mn−1. The influence of hydroxyl groups on Tg was also examined for low molecular weight (<2.2×104) polyisoprenes.

The Effect of Solvent on the Miscibility of Blends of Poly 1-[4-(3-carboxy-4-hydroxy-phenylazo)benzene Sulphonamido -1,2-ethanediyl, sodium salt)] (PAZO) and Polyhydroxybutyrate, (PHB)

2005 ◽  
Vol 13 (5) ◽  
pp. 443-452 ◽  
Author(s):  
*Lakshmi Sharma ◽  
Koji Nishida ◽  
Toshiji Kanaya
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Sodium Salt ◽  
Cost Effective ◽  
Photonic Materials ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Effect Of Solvent ◽  
Photonic Material ◽  
Commercial World

The commercial world demands new photonic materials, pandering to the consumer's every whim. The target now is to produce an eco-friendly, cost-effective photonic material. This is possible by blending poly 1-[4-(3-carboxy-4-hydroxy-phenylazo)benzene sulphonamido-1,2-ethanediyl, sodium salt)], (PAZO), with polyhydroxybutyrate, (PHB). We analysed the behaviour of PAZO/PHB blends in various solvents, dependent on the solubility parameter calculations for amorphous PHB. Differential Scanning Calorimetry was employed to determine the glass transition temperatures and to assess miscibility. This paper aims to address and establish the effect of the solvent on the miscibility of PHB/PAZO blends. We have established that a complex, is formed at high PHB concentrations, via the O-H bond of the PHB and PAZO in all solvents.

scholarly journals Differential Scanning Calorimetry for Determining the Thermodynamic Properties of Selected Honeys

2015 ◽  
Vol 59 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Jolanta Tomaszewska-Gras ◽  
Sławomir Bakier ◽  
Kamila Goderska ◽  
Krzysztof Mansfeld
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermodynamic Properties ◽  
Sugar Content ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Complete Liquefaction

Abstract Thermodynamic properties of selected honeys: glass transition temperature (Tg), the change in specifi c heat capacity (ΔCp), and enthalpy (ΔH) were analysed using differential scanning calorimetry (DSC) in relation to the composition i.e. water and sugar content. Glass transition temperatures (Tg) of various types of honey differed significantly (p<0.05) and ranged from -49.7°C (polyfloral) to -34.8°C (sunflower). There was a strong correlation between the Tg values and the moisture content in honey (r = -0.94). The degree of crystallisation of the honey also influenced the Tg values. It has been shown that the presence or absence of sugar crystals influenced the glass transition temperature. For the decrystallised honeys, the Tg values were 6 to 11°C lower than for the crystallised honeys. The more crystallised a honey was, the greater the temperature difference was between the decrystallised and crystallized honey. In conclusion, to obtain reliable DSC results, it is crucial to measure the glass transition after the complete liquefaction of honey.

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