Breadth of glass transition temperature in styrene/acrylic acid block, random, and gradient copolymers: Unusual sequence distribution effects

2007 ◽  
Vol 45 (20) ◽  
pp. 2842-2849 ◽  
Author(s):  
Christopher L. H. Wong ◽  
Jungki Kim ◽  
John M. Torkelson
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Acrylic Acid ◽  
Sequence Distribution ◽  
Gradient Copolymers

scholarly journals Synthesis and Characterization of Poly(Acrylic Acid)/Organo-Modified Nanohydroxyapatite Nanocomposites: Thermal, Optical and Biocompatibility Properties

2018 ◽  
Vol 18 (3) ◽  
pp. 54-67 ◽  
Author(s):  
M. E. Diken ◽  
S. Doğan ◽  
Y. Turhan ◽  
M. Doğan
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Simulated Body Fluid ◽  
Acrylic Acid ◽  
Body Fluid ◽  
Synthesis And Characterization ◽  
Uv Absorbance ◽  
Poly Acrylic Acid

AbstractThe aim of this study was to investigate the structural, thermal, optical and biocompatibility properties of poly(acrylic acid)(PAA)/organo-modified nanohydroxyapatite (OM-nHAp) nanocomposites synthesized by solvent intercalation method. The characterization of PAA/OM-nHAp nanocomposites was made by different techniques. SEM and TEM results showed that OM-nHAp particles were dispersed in the nanoscale into PAA matrix and that they were uniformly distributed within film. Glass transition temperature of PAA increased with OM-nHAp content. Ultraviolet (UV) absorbance experiments showed that PAA had a higher UV transmission than its nanocomposites. The biocompatibility of nanocomposites was also examined in simulated body fluid.

scholarly journals Hydrogels Obtained via γ-Irradiation Based on Poly(Acrylic Acid) and Its Copolymers with 2-Hydroxyethyl Methacrylate

2020 ◽  
Vol 10 (14) ◽  
pp. 4960 ◽  
Author(s):  
Marin Micutz ◽  
Rodica Mihaela Lungu ◽  
Viorel Circu ◽  
Monica Ilis ◽  
Teodora Staicu
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Acrylic Acid ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Chemical Transformations ◽  
Hydroxyethyl Methacrylate ◽  
Γ Irradiation ◽  
Crosslinking Degree

Hydrogels containing both carboxyl and hydroxyl functional groups have been prepared by γ-irradiation of either aqueous solutions of acrylic acid (AA) and mixtures of AA and 2-hydroxyethyl methacrylate (HEMA) in different ratios, or aqueous solutions of poly(AA), PAA, and poly(AA-co-HEMA) obtained via solution polymerization. A higher absorbed dose is required in order to prepare hydrogels from monomer solutions, compared with those from polymer solutions. The range for the absorbed doses was chosen so that the probability of crosslinking reactions is higher than that of degradation ones. As the radiation energy deposited in a sample increases, the equilibrium swelling degree and the average molar mass between crosslinks diminishes. Chemical transformations induced by radiation were investigated by means of FTIR spectroscopy and thermal analysis of polymers before and after irradiation. For all these systems, the formation of a three-dimensional network enhances the glass transition temperature and thermal stability, but a further increase in the crosslinking degree may have the reverse effect on the glass transition temperature. Depending on the preparation protocol and/or hydrogel composition, superabsorbent materials that can bind different compounds throughout side functional groups may be obtained.

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