scholarly journals Synthesis, Characterization and Evaluation of the Transformations in Hibiscus sabdariffa-graft-poly(butyl acrylate)

2008 ◽  
Vol 5 (s1) ◽  
pp. S980-S986 ◽  
Author(s):  
B. S. Kaith ◽  
Aashish Chauhan
Keyword(s):  
Thermal Resistance ◽  
Butyl Acrylate ◽  
Moisture Absorption ◽  
Graft Copolymerization ◽  
Graft Copolymers ◽  
Crystallinity Index ◽  
Hibiscus Sabdariffa ◽  
Reaction Parameters ◽  
Chemical Changes

Different reaction parameters for the graft copolymerization of butyl acrylate ontoHibiscus sabdariffafiber were optimized. Graft copolymers thus obtained were subjected to characterization using XRD, TGA, DTA, SEM and FTIR techniques and were evaluated for physio-chemical changes in the behavior. The percentage crystallinity and crystallinity index were found to decrease with increase in grafting while there was reduction in moisture absorption and increase in chemical, thermal resistance of the graft copolymers.

Physical, chemical, thermal, and mechanical assessments of Roselle-reinforced composites

2012 ◽  
Vol 32 (2) ◽  
Author(s):  
Ashish Chauhan ◽  
Balbir Singh
Keyword(s):  
Mechanical Strength ◽  
Moisture Absorption ◽  
Chemical Resistance ◽  
Phenol Formaldehyde ◽  
Graft Copolymers ◽  
Young Modulus ◽  
Hibiscus Sabdariffa ◽  
Reinforced Composites ◽  
High Mechanical Strength ◽  
Physicochemical Changes

Abstract Hibiscus sabdariffa stem fiber has 73.9% cellulose, high mechanical strength and is found in abundance throughout the world. Hibiscus sabdariffa graft copolymers were synthesized, characterized by FTIR, XRD, TGA, DTA, and SEM techniques, and evaluated for physicochemical changes in properties such as moisture absorption, chemical resistance against 1 n NaOH and 1 n HCl. These graft copolymers were reinforced in phenol-formaldehyde polymer matrix to form biocomposites that were characterized by advanced techniques and evaluated for physicochemicothermal resistance. The mechanical strength was accessed on the basis of hardness, flexural strength, Young modulus, and stress at the limit of proportionality, which was found to be high. These novel materials could have numerous scientific and industrial application to pave the way for development of technology.

Synthesis and Evaluation of Advanced Graft Copolymers

2012 ◽  
Vol 28 (1) ◽  
pp. 27-42
Author(s):  
Ashish Chauhan ◽  
Balbir Kaith
Keyword(s):  
Moisture Absorption ◽  
Graft Copolymers ◽  
Gentian Violet ◽  
Monomer Concentration ◽  
Crystallinity Index ◽  
Ethyl Acrylate ◽  
Ceric Ammonium Nitrate ◽  
Waste Biomass ◽  
Graft Yield ◽  
Xrd Techniques

The paper deals with characterisation and evaluation of the transformations in waste biomass Hibiscus sabdariffa stem fibre on graft copolymerisation with ethyl acrylate (EA) and butyl acrylate (BA) monomer, using a ceric ammonium nitrate–nitric acid initiator system. Different reaction parameters, such as temperature, time, initiator concentration, monomer concentration, and pH, were optimised to obtain the maximum graft yield. The graft copolymers thus formed were characterised by FTIR, SEM, TGA, DTA, and XRD techniques. The swelling behaviour of graft copolymers in different solvents was studied and screened for dye uptake behaviour in 0.1% gentian violet dye. With increase in percentage grafting, the percentage crystallinity, crystallinity index, and moisture absorption were found to decrease, whereas the chemical resistance (against 1N HCl and 1N NaOH), thermal resistance, and solubility in organic solvents were found to increase.

Synthesis and Characterization of Reactive Graft Copolymers of Poly(butyl Acrylate) and Cellulose

2005 ◽  
Vol 13 (5) ◽  
pp. 467-478
Author(s):  
Ghanshyam S. Chauhan ◽  
Baljit Singh ◽  
Suresh Kumar ◽  
Anupama Chinkara
Keyword(s):  
Butyl Acrylate ◽  
Metal Ion ◽  
Graft Copolymerization ◽  
Graft Copolymers ◽  
Optimum Conditions ◽  
Ion Sorption ◽  
Graft Yield ◽  
Ft Ir ◽  
Structural Aspects

Butyl acrylate was graft copolymerized onto cellulose extracted from pine needles by a simultaneous gamma radiation initiation method. Optimum conditions for the maximum graft yield were established. Polymerization and grafting parameters such as %grafting (Pg), % grafting efficiency (%GE), rates of polymerization (Rp), homopolymerization (Rh) and graft copolymerization (Rg) were also determined. Grafted cellulose was further functionalized to produce poly(acryloyl hydroxylamine) [Cell-g-poly(CONHOH)] so as to generate active (-CONHOH) groups on the cellulose backbone. Graft copolymers were characterized by elemental analysis, by FT-IR and by a swelling study. An attempt was also made to study the sorption of Fe+2 and Cu+2 as model metal ions onto the candidate copolymers, in order to investigate their selectivity in metal ion sorption and to determine the effect on metal ion sorption of the structural aspects of the hydrogels and other functionalized graft copolymers, so as to identify their end-uses.

A Study of Crystallinity of Graft Copolymers of Flax Fiber with Binary Vinyl Monomers

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
B.S. Kaith ◽  
Susheel Kalia
Keyword(s):  
Binary Mixture ◽  
Graft Copolymerization ◽  
Graft Copolymers ◽  
Crystallinity Index ◽  
Vinyl Monomer ◽  
Flax Fiber ◽  
Vinyl Monomers ◽  
X Ray Diffraction ◽  
X Ray

AbstractThe present paper deals with graft copolymerization of binary vinyl monomer mixtures onto flax fiber. Maximum grafting (86.02 %) has been found with MMA+EA binary mixture. Percentage crystallinity and crystallinity index of graft copolymers were measured with X-ray diffraction (XRD) technique. Crystallinity of flax decreases on grafting with binary vinyl monomer mixtures. Flax showed the highest value of percentage crystallinity (76.96 %) and crystallinity index (0.7005) in comparison to Flax-g-copolymers.

Radiation Induced Graft Copolymerization of Vinyl Acetate and Isopropenyl Acetate Onto Isotactic Polypropylene

1996 ◽  
Vol 61 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Bhupendra N. Misra ◽  
G. S. Chauhan ◽  
Inderjeet Kaur
Keyword(s):  
Vinyl Acetate ◽  
Isotactic Polypropylene ◽  
Graft Copolymerization ◽  
Optimum Conditions ◽  
Reaction Parameters ◽  
Maximum Percentage ◽  
Radiation Induced ◽  
Isopropenyl Acetate

Radiation-induced graft copolymerization of vinyl acetate (VAC) and isopropenyl acetate (PAC) onto isotactic polypropylene (IPP) has been studied. The percentage of grafting was calculated for various reaction parameters, and the optimum conditions for attaining the maximum percentage of grafting were determined. Maximal achieved extents of grafting are 39% and 29% for VAC and PAC, respectively. The reactivity of the two monomers with respect to grafting is discussed.

Preparation and characterization of oxidized starch-graft-poly(styrene-butyl acrylate) latex via emulsion polymerization

2014 ◽  
Vol 34 (7) ◽  
pp. 611-616 ◽  
Author(s):  
Shijie Cheng ◽  
Jun Xu ◽  
Yumin Wu
Keyword(s):  
Emulsion Polymerization ◽  
Butyl Acrylate ◽  
Colloidal Stability ◽  
Graft Copolymerization ◽  
Scanning Calorimetry ◽  
Oxidized Starch ◽  
Ir Transmission ◽  
Ft Ir ◽  
Synthetic Latex

Abstract Oxidized starch-graft-poly(styrene-butyl acrylate) [OS-g-P(St-BA)] latex was synthesized by the graft copolymerization of OS with St and n-butyl acrylate (BA) via emulsion polymerization. The graft copolymers were characterized by Fourier transform infrared (FT-IR), transmission electronic microscopy (TEM), dynamic light scattering, thermogravimetry (TG), and differential scanning calorimetry (DSC). The effects of the amount of OS, monomers, and initiator on graft copolymerization were investigated. Under the optimal conditions, the percentage of graft (PG), grafting efficiency (GE), and ζ potential could reach 256.5%, 41.7%, and -30.1 mV, respectively. The results indicated that the OS grafted onto particles greatly enhanced the colloidal stability of latex. The thermal stability properties of OS-g-P(St-BA) were also improved by the addition of OS. The OS-g-P(St-BA) latex may be used to partly replace the conventional synthetic latex for paper coating.

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