scholarly journals Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate)

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Efkan Çatıker ◽  
Tahsin Filik
Keyword(s):  
Acrylic Acid ◽  
Hydrogen Transfer ◽  
Direct Synthesis ◽  
Bulk Polymerization ◽  
Swelling Behavior ◽  
Raw Material ◽  
Hyperbranched Poly ◽  
Wide Ph Range ◽  
Ph Range ◽  
Poly Acrylic Acid

Hyperbranched poly(acrylic acid-co-3-hydroxypropionate) (PAcHP) was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate) (PHP). However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

scholarly journals Antioxidant properties, quantification and stability of betalains from pitaya (Hylocereus undatus) peel

2014 ◽  
Vol 45 (2) ◽  
pp. 323-328 ◽  
Author(s):  
Fernanda Robert de Mello ◽  
Claudia Bernardo ◽  
Caroline Odebrecht Dias ◽  
Luciano Gonzaga ◽  
Edna Regina Amante ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Antioxidant Properties ◽  
Raw Material ◽  
High Concentration ◽  
Natural Colorant ◽  
Wide Ph Range ◽  
Hylocereus Undatus ◽  
Ph Range ◽  
Promising Source

Pitaya peel can be used as a raw material for betalains extraction. The aim of this research was to quantify phenolic compounds, antioxidant activity and betalains on pitaya peel. Furthermore, evaluate the betalains stability against various pH conditions and exposure time of heating. The results showed that pitaya peel contains phenolic compounds and presented antioxidant activity. Moreover it showed high concentration of betalains (101.04mg equivalent to betanin. 100g-1) which were stable over a wide pH range (3.2 - 7.0) and were resistant to heating (100oC) up to 10 minutes at pH range from 3.7 to 5.5. Therefore, pitaya peel is a promising source of betalains which can be applied as a natural colorant for food.

Synthesis and the Swelling Behavior of Sodium Alginate Graft Poly (Acrylic Acid-co-acrylamide)/Graphite Oxide Super Absorbent Composite

2019 ◽  
Vol 61 (5) ◽  
pp. 680-690 ◽  
Author(s):  
Linhui Zhu ◽  
Yu Liu ◽  
Bin Zhou ◽  
Hongduo Tang ◽  
Fangyuan Wang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Sodium Alginate ◽  
Graphite Oxide ◽  
Swelling Behavior ◽  
Poly Acrylic Acid

scholarly journals Fabrication of Eco-Friendly Superabsorbent Composites Based on Waste Semicoke

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2347
Author(s):  
Yongsheng Wang ◽  
Yongfeng Zhu ◽  
Yan Liu ◽  
Aiqin Wang
Keyword(s):  
Acrylic Acid ◽  
Ph Value ◽  
High Water ◽  
Sem Analysis ◽  
Water Absorbency ◽  
Ammonium Persulphate ◽  
Wide Ph Range ◽  
Maximum Water ◽  
Ph Range ◽  
Superabsorbent Composites

A series of novel superabsorbent composites of poly(acrylic acid)/semicoke were prepared by polymerization of acrylic acid using ammonium persulphate as initiator, N,N′-methylenebisacrylamide as crosslinker and semicoke which was the by-product of coal carbonizing as the inorganic components. FTIR and SEM analysis indicated that the superabsorbent composites had been successfully polymerized and the semicoke participated in construction of the 3D polymeric network. Meanwhile, the effects of initiator, crosslinker, semicoke, and neutralization degree, as well as the pH value, were investigated, and the results showed that superabsorbent composites containing 10% of semicoke possessed the maximum water absorbency of 584 g/g in distilled water and 75 g/g in 0.9% NaCl solution. The superabsorbent composites kept the high water absorbency within a wide pH range of 4–11, and still exhibited better re-swelling capability even after seven times. The superabsorbent composite with its excellent performance is a potential water-retaining agent used in agriculture.

Deflocculation of Alumina Suspensions Using Polyelectrolyte Dispersants

2007 ◽  
Vol 352 ◽  
pp. 81-84
Author(s):  
Yang Qiao Liu ◽  
Lian Gao
Keyword(s):  
Acrylic Acid ◽  
Zeta Potential ◽  
Synergistic Effect ◽  
Surface Charge ◽  
Functional Groups ◽  
Ph Value ◽  
Rheological Measurements ◽  
Gel Casting ◽  
Ph Range ◽  
Poly Acrylic Acid

In this paper, the dispersing abilities of three polyelectrolytes, poly (acrylic acid), poly (acrylic acid-co-acrylate), and a four-member copolymer containing various anionic functional groups were tested for aqueous Al2O3 suspensions. The influence of the dispersants on the surface charge of the powder was evaluated by measuring the zeta potential in dilute Al2O3 suspensions. It was found that all the three dispersants shifted the isoelectric point to a lower pH value. Rheological measurements showed that the four-member dispersant decreased the viscosity in the widest pH range, which should be ascribed to the synergistic effect of different functional groups. The 58vol% concentrated Al2O3 slurry using the four-member dispersant was further consolidated using gel casting and was fully sintered at 1600oC.

Effect of pH on the Dispersion Stability of Aqueous Ferric Oxide Suspension

2007 ◽  
Vol 544-545 ◽  
pp. 717-720 ◽  
Author(s):  
C.H Lee ◽  
Eun Hee Lee
Keyword(s):  
Acrylic Acid ◽  
Zeta Potential ◽  
Ferric Oxide ◽  
Dispersion Stability ◽  
Effect Of Ph ◽  
Acidic Solutions ◽  
Aqueous Suspensions ◽  
Wide Ph Range ◽  
Ionization Behavior ◽  
Ph Range

We have studied the effect of pH on the dispersion stability of aqueous suspensions of Fe2O3 powders over a wide pH range in the presence of the poly (acrylic acid) (PAA). In order to investigate the ionization behavior of the PAA, pH of PAA solutions was measured. Sedimentation and zeta-potential measurements were conducted on aqueous Fe2O3 suspensions to characterize the dispersion stability of the suspensions. The PAA was ionized over a wide pH range and the quantity of ionization was abruptly increased at pH > 10. Thus, the dispersion of the Fe2O3 powders was observed even in acidic solutions and the dispersion stability of the suspensions increased as pH of the solutions increased. The magnitude of zeta-potential values increased with increasing pH.

Swelling behavior and drug release of poly(vinyl alcohol) hydrogel cross-linked with poly(acrylic acid)

2008 ◽  
Vol 16 (3) ◽  
pp. 189-193 ◽  
Author(s):  
Hongsik Byun ◽  
Byungpyo Hong ◽  
Sang Yong Nam ◽  
Sun Young Jung ◽  
Ji Won Rhim ◽  
...  
Keyword(s):  
Drug Release ◽  
Acrylic Acid ◽  
Vinyl Alcohol ◽  
Swelling Behavior ◽  
Poly Vinyl Alcohol ◽  
Poly Acrylic Acid
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