Multiple Glass Transitions of Block Polymers. II. Differential Scanning Calorimetry of Styrene-Diene Block Copolymers

1970 ◽  
pp. 43-51 ◽  
Author(s):  
R. M. Ikeda ◽  
M. L. Wallach ◽  
R. J. Angelo
Keyword(s):  
Differential Scanning Calorimetry ◽  
Block Copolymers ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
Block Polymers

Differential Scanning Calorimetry (DSC) Analysis of Abaca Fibre (Musa Textile Nee) Reinforced High Impact Polystyrene (HIPS) Composites

2011 ◽  
Vol 295-297 ◽  
pp. 929-933 ◽  
Author(s):  
E.H. Agung ◽  
S.M. Sapuan ◽  
M.M.H. Megat Ahmad ◽  
H.M.D.K. Zaman ◽  
U. Mustofa
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Optimum Condition ◽  
Amorphous State ◽  
Heat Content ◽  
High Impact ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
High Impact Polystyrene

Differential scanning calorimetry (DSC) was used to study the thermal behaviour of abaca fibre reinforced high impact polystyrene (HIPS) composites. Thermal analysis is based upon the detection of changes in the heat content (enthalpy) and the glass transition temperature (Tg) of optimum condition of abaca fibre reinforced HIPS composites. In this research, glass transitions temperature (Tg) of neat HIPS occurred below the Tg of optimum condition of composites as the temperature of an amorphous state. The endothermic peak of composites was in to range 430-435°C including neat HIPS and it observed that enthalpy of abaca fibre reinforced HIPS composites yielded below the neat HIPS 748.79 J/g.

Thermal Analysis of Fresh and Mature Oil Paint Films: The Effect of Pigments as Driers and the Solvent Leaching of Mature Paint Films

1990 ◽  
Vol 185 ◽  
Author(s):  
Christopher W. McGlinchey
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Linseed Oil ◽  
Glass Transitions ◽  
Lead White ◽  
Thermal Transitions ◽  
Scanning Calorimetry ◽  
Titanium White ◽  
Drying Properties ◽  
Paint Films

AbstractThe effect of titanium white, zinc white and lead white on the drying properties of poppy, walnut and linseed oil are analyzed by differential scanning calorimetry (DSC). All of the fresh films undergo complex thermal transitions between -100 and O°C. For some of the dried films subambient transitions that resemble glass transitions occur at about -30 O°C. After exposure to certain solvents, these sub-ambient transitions disappear or are reduced significantly. It is suggested that samples with diminished sub-ambient transitions become more brittle as a result of the loss of materials that act as plasticizers.

Direct Detection of Effective Glass Transitions in Miscible Polymer Blends by Temperature-Modulated Differential Scanning Calorimetry

2005 ◽  
Vol 38 (6) ◽  
pp. 2355-2361 ◽  
Author(s):  
Yohei Miwa ◽  
Kaori Usami ◽  
Katsuhiro Yamamoto ◽  
Masato Sakaguchi ◽  
Masahiro Sakai ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Polymer Blends ◽  
Direct Detection ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Miscible Polymer Blends

Effect of Architecture on the Crystal Morphology of Block Copolymers. Small-Angle X-ray Scattering and Differential Scanning Calorimetry

2002 ◽  
Vol 35 (12) ◽  
pp. 4838-4840 ◽  
Author(s):  
Chiraphon Chaibundit ◽  
Withawat Mingvanish ◽  
Colin Booth ◽  
Shao-Min Mai ◽  
Simon C. Turner ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Block Copolymers ◽  
Small Angle ◽  
Crystal Morphology ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Quasi-isothermal temperature-modulated differential scanning calorimetry (TMDSC) for the separation of reversible and irreversible thermodynamic changes in glass transition and melting ranges of flexible macromolecules

2009 ◽  
Vol 81 (10) ◽  
pp. 1931-1952 ◽  
Author(s):  
Bernhard Wunderlich
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Thermal Analyses ◽  
Data Bank ◽  
Irreversible Thermodynamic ◽  
Modulated Dsc ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Heat Capacity Measurements

With standard differential scanning calorimetry (DSC), it is possible to derive calorimetric data for equilibrium or metastable samples. The introduction of temperature-modulated DSC (TMDSC) permits in its quasi-isothermal (non-scanning) mode (TMDC), long-time apparent heat capacity measurements of high precision (±1 %). For flexible molecules, heat capacity measurements from the various calorimetric methods could be combined in the ATHAS Data Bank, which now contains experimental data for over 200 materials. These data were linked to the vibrational and large-amplitude motion of the constituent atoms and molecules, to provide a base for the judgement of the thermal analyses, extending outside the range of equilibrium or metastability with an error of only 2-5 %. The TMDC together with DSC is now able to quantitatively assess the reversibility of thermal processes. A sufficient number of systems have been analyzed in this fashion to develop better understanding of macro-, micro-, and nanophases of flexible macromolecules. The new concepts discussed are: (1) multiple glass transitions due to possible rigid-amorphous fractions (RAFs) and glass transitions within crystals, both observed in semicrystalline macromolecules, and (2) locally reversibly melting on the surface of chain-folded crystals. The locally reversible melting decreases with crystal perfection and also disappears when the chains become rigid.

Effect of Molecular Weight on Glass Transition by Differential Scanning Calorimetry

1974 ◽  
Vol 52 (18) ◽  
pp. 3170-3175 ◽  
Author(s):  
Louis-Philippe Blanchard ◽  
Jean Hesse ◽  
Shadi Lal Malhotra
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Glass Transition ◽  
Heating Rate ◽  
Low Molecular Weight ◽  
Glass Transitions ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Polystyrene Sample

The influence of molecular weight (900 to 1.8 × 106) on the glass transition temperature of low polydispersity polystyrene (anionically prepared) has been studied by differential scanning calorimetry at heating rates of 5 to 80 °C min−1. Over the range of molecular_weight studied, and at an extrapolated heating rate of 1 °C min−1,[Formula: see text] A thermally prepared polystyrene sample ([Formula: see text]and Pd = 3.2) showed a Tge value of 93 °C, some 10° below the value predicted by the above equation. Low molecular weight species in the highly polydisperse sample are believed to be responsible for the discrepancy. The changes in heat capacity brought about by the glass transitions are accompanied in all cases on heating by an endothermic peak and this regardless of the heating rate (even extrapolated to 1 °C min−1) or the molecular weight of the sample, suggesting that the glass transition phenomenon encountered with polystyrene is a process involving a positive heat effect.

Synthesis of Nano-Polyaniline Using Different Ultrasonic Wave

2014 ◽  
Vol 695 ◽  
pp. 207-210 ◽  
Author(s):  
Muhamad Rasyidi Husin ◽  
Agus Arsad ◽  
Othman Y. Alothman
Keyword(s):  
Molecular Structure ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Hydrochloric Acid ◽  
Thermal Characteristics ◽  
Ammonium Persulfate ◽  
Cross Linking ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
Frequency Wave

Polyaniline (PANI) was synthesized by using ultrasonic polymerizations at various frequencies of 5 to 20 kHz. PANI was synthesized in the present using hydrochloric acid (HCl) as a dopant and ammonium persulfate (APS) as an oxidant. The characteristics of PANI based on 1H proton, its molecular structure was characterized by using nuclear magnetic resonance (NMR) and at 7-8 ppm confirmed the PANI structure. Thermal characteristics have also been investigated by using differential scanning calorimetry (DSC). Glass transitions temperature (Tg) at about ~100 °C was it is correlated observed due to recrystallization or cross-linking reaction of PANI. The polymerization at frequency wave of 20 kHz shows the best overall properties of produced PANI nanofiber.

Phase Transitions in Polyester-Polyether Copolymers

2020 ◽  
Vol 869 ◽  
pp. 308-314
Author(s):  
Arsen M. Kharaev ◽  
Rima Ch. Bazheva ◽  
Zakhirat Kh. Sultigova ◽  
Zareta I. Inarkieva ◽  
Asker Kongapshev
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transitions ◽  
Block Copolymers ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Polytetramethylene Oxide

Using differential scanning calorimetry, phase transitions in polycarbonate-polytetramethylene oxide block copolymers were studied. It is shown that, depending on the ratio of rigid polycarbonate and flexible polytetramethylene oxide units, block copolymers can be two-phase or four-phase. It is shown that phase transitions in copolymers of a polyester-polyether depend on the ability to crystallize the components.

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