Effect of Reaction Parameters on Swelling Properties of Poly (Acrylic Acid-Acrylamide/Montmorillonite) Nanocomposite Superabsorbents

PE-LD samples containing two types of filler in concentrations of 2-10 wt.% (zeolite TMAZ 7 and nanoclay Cloisite 20A). The microstructural and morphological changes as well as mechanical features of samples were characterized by scanning electronic microscopy (SEM) and by tensile tests. The thermal degradation of PE-LD composites were achieved using thermogravimetric analysis (TGA). The permeability, the diffusion and the solubility constants of the gases in modified PE-LD films were calculated and the gas separation (N 2 / O 2 ; O 2 /CO 2 ) ability was determined. In the presence of nanoparticles, at lower content, the value of oxygen permeability of PE-LD decreases.

Section: Thermal Propertiesmentioning

confidence: 99%

Preparation and Properties of Low Density Polyethylene Film Modified by Zeolite and Nanoclay

Ščetar

Siročić

Hrnjak-Murgić

et al. 2013

Section: Introductionmentioning

confidence: 99%

“…Although, most of the SAPs commercially produced are anionic (based on acrylic acid and its derivatives) [2] , a wide variety of other superabsorbent polymers have been synthesized [5][6][7][8][9] . The cationic monomers have also been polymerized, either independently [10] or with anionic SAPs to obtain amphoteric SAPs [11][12][13][14][15] .The synthesis routes of the monomer-based SAPs are well established, but there are only a few studies reporting their degradation [16][17] .The SAPs constitute a significant part of domestic waste, making the degradation studies of the synthetic SAPs important. Li and Cui [16] subjected acrylic acid and acrylamide-based SAP to ultravioletinduced decomposition and quantified the degradation by measuring the weight of the SAP at the end of the degradation.…”

mentioning

confidence: 98%

Photo and Thermal Degradation of a Cationic Superabsorbent Polymer

Shukla

Bhagat

Madras

2013

A cationic superabsorbent polymer (SAP) was synthesized by carrying out the polymerization of [2-(methacryloyloxy)ethyl] trimethyl ammonium chloride) with N,N 0 -methylenebisacrylamide as the cross-linking agent. The SAP was subjected to degradation in dry and the equilibrium swollen state by thermo gravimetric analysis and exposure to ultraviolet radiation, respectively. The photodegradation was monitored by measuring changes in the swelling capacity and the dry weight of the SAP. The thermal degradation of the SAP occurred in three stages after the initial removal of moisture and the activation energies of the decomposition were determined. INTRODUCTIONThree-dimensional cross-linked networks of hydrophilic polymers that are able to absorb and retain liquids more than 100 times of their own weight are known as superabsorbent polymers (SAPs) [1] . The SAPs contain ionic repeat units, and could classified be as anionic, cationic, amphoteric, or zwitterionic [2] . They find applications in personal hygiene products [2] , food packaging [2] , wound healing devices [3] and water treatment [4] . Although, most of the SAPs commercially produced are anionic (based on acrylic acid and its derivatives) [2] , a wide variety of other superabsorbent polymers have been synthesized [5][6][7][8][9] . The cationic monomers have also been polymerized, either independently [10] or with anionic SAPs to obtain amphoteric SAPs [11][12][13][14][15] .The synthesis routes of the monomer-based SAPs are well established, but there are only a few studies reporting their degradation [16][17] .The SAPs constitute a significant part of domestic waste, making the degradation studies of the synthetic SAPs important. Li and Cui [16] subjected acrylic acid and acrylamide-based SAP to ultravioletinduced decomposition and quantified the degradation by measuring the weight of the SAP at the end of the degradation. Their study, although the first report of its kind, did not provide information about the changes in the swelling capacity of the SAPs during the degradation. In our previous study, we had adopted an improved technique for the photodegradation of poly (acrylic acid-co-sodium acrylate-co-acrylamide) SAPs [17] .The changes in the swelling capacity as well as the residual weights of the SAPs were measured during the degradation and a possible mechanism of the degradation of SAPs was proposed. The SAPs were found to undergo degradation in two stages. In the first stage, the network became sparse and the swelling capacity increased but the residual weight fraction was constant. The rupture of the three-dimensional network took place in the second stage, and thus both the swelling capacity and the residual weights reduced drastically.In the present study, we report the photodegradation of a cationic SAP by the earlier developed method [18] . Here we extend the study to investigate the effect of cross-link density on the photodegradation of the SAP. The cationic SAP poly([2-(methacryloyloxy)ethyl]trimethyl ammonium chloride) (PMALETMAC) was synth...

“…These nanosize composites are particularly promising in applications such as catalysis, surface coatings, chromatography and biotechnologies. Several articles have summarized recent developments on organic= inorganic nanosize composites [2][3][4][5] .…”

Section: Introductionmentioning

confidence: 99%

Untreated Silica Nanoparticles Containing Poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid) Composite—Effect of Copolymer Composition

Bhardwaj

Aggarwal

Mandal

2012

Poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid)/Silica [Poly(AM-co-AMPSA)/SiO 2 ] core-shell composite nanogels with silica as core and hydrophilic polymer with functional groups such as sulfonic acid, amido, as shell were prepared by microemulsion polymerization without surface treatment of silica and upto 5.5 mole% of AMPSA in feed to control the particle size as well as morphology. The synthesized intercalated composites were produced with controllable sizes ranging from 44-77 nm in diameter. The repared sulfonic acid based silica core-shell composite nanogels were characterized by dynamic light scattering, transmission electron microscope, Fourier transform infrared spectrophotometer, thermogravimetric analyzer, differential scanning calorimeter, scanning electron microscope and X-ray diffraction. The encapsulation of functional polymer shell onto the silica particles was driven by the hydrogen-bonding interaction between sulfonic acid and amido groups of AMPSA with Si-O linkages. The onset degradation temperature is increased from 227 C to 262 C in copolymer-silica composites which indicates improved thermal stability. The shifting of glass transition temperature from 194 C to 203 C in copolymeric composite nanogels further confirms the existence of strong interactions of silica filler with copolymer chains. Also the chemical composition of polymeric chains and the affinity of polymer chains and silica influenced the morphology.