Graft‐copolymerization of starch with acrylamide, II. Thermal behaviour of graft copolymers

Singh, Om Pal; Sandle, N. K.; Varma, I. K.

doi:10.1002/apmc.1984.051210117

Cited by 15 publications

(12 citation statements)

References 2 publications

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“…All of the grafting parameters decreased continuously in a gradual manner with increasing concentration of MA, except for the homopolymer, which showed the opposite trend, whereas the conversion increased up to 7.5 Â 10 À2 mol/dm 3 . After that, it decreased (Table II).…”

Section: Effect Of the Ma Concentrationmentioning

confidence: 78%

“…Beyond this concentration, %G, %E, %A, and R g decreased. However, the conversion increased as the concentration of ACM increased up to 10 Â 10 À2 mol/dm 3 . The increments in %G, %E, %A, and R g were due to the greater availability of ACM at the close proximity of the polymer backbone.…”

Section: Effect Of the Ma Concentrationmentioning

confidence: 94%

“…The effect of MA on the grafting parameters was studied by variation of the concentration of MA from 2.0 to 12.5 Â 10 À2 mol/dm 3 . All of the grafting parameters decreased continuously in a gradual manner with increasing concentration of MA, except for the homopolymer, which showed the opposite trend, whereas the conversion increased up to 7.5 Â 10 À2 mol/dm 3 .…”

Section: Effect Of the Ma Concentrationmentioning

confidence: 99%

“…The swelling behavior of the graft copolymer was examined in water for 1 h; different samples of the graft copolymer were prepared by variation of the concentration of ACM from 5.0 to 40.0 Â 10 À2 mol/ dm 3 . We carried out these studies by taking 0.05 g of the graft copolymer sample in 10 mL of triple-distilled water and keeping it undisturbed for 1 h. We removed the surface water on the swollen graft copolymer by safely pressing it between the folds of tissue paper; an increased in the weight was recorded.…”

Section: Swellingmentioning

confidence: 99%

“…Several studies on the graft copolymerization of various vinyl monomers onto natural polymers have been done to modify various properties of natural polymers, such as hygroscopicity, thermal property, and biodegradability. It has been reported that the grafting of acrylamide (ACM) 3 onto starch imparted thermal stability, which increased with increasing ACM concentration, and the resulting graft copolymer was used as a retention aid in paper making, a binder between fibers to compensate for the decrease in the strength of filler retention. 4 The water-retention capacity of cellulose increases after the grafting of ACM 5 onto it, and corn starch-g-ACM has been used in flocculation for the treatment of wastewater containing Hg 2þ from industry.…”

Section: Introductionmentioning

confidence: 99%

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Vanadium(V)/mandelic acid initiated graft copolymerization of acrylamide onto guar gum in an aqueous medium

Srivastava

Mishra

Singh

et al. 2009

J of Applied Polymer Sci

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ABSTRACT:The graft copolymerization reaction of acrylamide onto guar gum with a vanadium(V)/mandelic acid redox pair was carried out in an N 2 atmosphere. The optimum concentrations of vanadium(V), mandelic acid, hydrogen ions, acrylamide, and guar gum for the maximum percentage of grafting were 6.0 Â 10 À3 , 2.0 Â 10 À2 , 55.0 Â 10 À2 , and 20.0 Â 10 À2 mol/dm 3 and 110.1 Â 10 À2 g/dm 3 , respectively. The optimum time and temperature of reaction were 90 min and 35 C, respectively, and during the study of [H þ ] variation, a prompt change in the value of the grafting parameters was observed. The maximum percentage of swelling of the graft copolymer was achieved at room temperature in 1 h. Studies of the flocculation, viscosity, and metal-ion absorption capacity were also performed. The synthesized graft copolymer was characterized by Fourier transform infrared spectroscopy and thermogravimetric analyses, which showed that the grafted guar gum was thermally more stable than the ungrafted guar gum.

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Section: Effect Of the Ma Concentrationmentioning

confidence: 78%

Section: Effect Of the Ma Concentrationmentioning

confidence: 94%

Section: Effect Of the Ma Concentrationmentioning

confidence: 99%

Section: Swellingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Vanadium(V)/mandelic acid initiated graft copolymerization of acrylamide onto guar gum in an aqueous medium

Srivastava

Mishra

Singh

et al. 2009

J of Applied Polymer Sci

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Cu+2/mandelic acid redox pair initiated graft copolymerization acrylamide onto guar gum

Behari

Taunk

Tripathi

1999

J. Appl. Polym. Sci.

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ABSTRACT:The effect of reaction conditions on the grafting parameters during the grafting of acrylamide (ACM) onto guar gum (GOH) by using a Cu ϩ2 -mandelic acid (MA) redox couple was studied. On increasing the Cu ϩ2 ion concentration (0.5 ϫ 10 Ϫ2 to 1.0 ϫ 10 Ϫ2 mol dm Ϫ3 ), an increase in total conversion of monomer, grafting ratio, efficiency, and add on was observed. Grafting ratios increased with an increase in concentration of mandelic acid and reaches its maximum value at 0.8 ϫ 10 Ϫ2 mol dm Ϫ3 . It was observed that grafting onto guar gum takes place efficiently when monomer and hydrogen ion concentrations are 20.0 ϫ 10 Ϫ2 and 2.2 ϫ 10 Ϫ2 mol dm Ϫ3 , respectively. Optimum temperature and time for obtaining a maximum grafting ratio and efficiency was found to be 35 Ϯ 0.2°C and 2 h, respectively. The plausible mechanism of grafting was suggested. The graft copolymer was characterized by infrared spectroscopy and thermogravimetric analysis.

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Graft‐copolymerization of starch with acrylamide, III. Physical properties and enzymatic degradation

Singh

Sandle

Varma

1984

Angew. Makromol. Chem.

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Starch-graft-polyacrylamide (S-g-PAM) copolymers having different graft-on were prepared. The density of these copolymers was lower than that of starch. The grafting of acrylamide onto starch disrupted the granular structure of starch and a tight and compact structure was formed. Sheets of various copolymers and blends of starch and polyacrylamide were prepared by compression moulding. An improvement in tensile strength and elongation was observed in graft-copolymers. When heated at 100°C for 2 h, the grafted sample lost a great deal of strength and elasticity. S-g-PAM copolymers also showed more resistance to degradation by a-amylase. ZUSAMMENFASSUNG:Pfropfcopolymere aus Polyacrylamid auf Starke (S-g-PAM) mit verschiedenen Pfropfgraden wurden hergestellt. Die Dichte dieser Pfropfcopolymeren war niedriger als die von Starke. Die Pfropfung von Acrylamid auf Starke unterbricht die kornige Struktur der Starke und fuhrt zu einer festen und kompakten Struktur. Folien aus verschiedenen Copolymeren und Mischungen aus Starke und Polyacrylamid wurden durch Preaformen hergestellt. Eine Verbesserung der Zugfestigkeit und der Dehnung wurden an Pfropfcopolymeren beobachtet. Beim zweistundigen Aufheizen auf 100 "C verloren die Pfropfcopolymeren einen grol3en Teil ihrer Festigkeit und Elastizitat. S-g-PAM-Copolymere zeigten eine verbesserte Bestandigkeit gegen einen Abbau durch a-Amylase.

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Graft‐copolymerization of starch with acrylamide, II. Thermal behaviour of graft copolymers

Cited by 15 publications

References 2 publications

Vanadium(V)/mandelic acid initiated graft copolymerization of acrylamide onto guar gum in an aqueous medium

Vanadium(V)/mandelic acid initiated graft copolymerization of acrylamide onto guar gum in an aqueous medium

Cu+2/mandelic acid redox pair initiated graft copolymerization acrylamide onto guar gum

Graft‐copolymerization of starch with acrylamide, III. Physical properties and enzymatic degradation

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