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The purpose of this paper is to evaluate the efficiency of acrylated guar gum (AGG) as an additive in alkyd resin for improved mechanical properties and to optimize the results of such an addition.

For studying the effect of AGG on coating properties, guar gum was modified to various degrees of esterification and various compositions of alkyd systems were made by incorporating different concentrations of AGG. The mechanical and solvent absorption of the unmodified and modified alkyd systems were characterized.

The incorporation of AGG into alkyd coating showed significant improvement of mechanical properties over the unmodified one. The modification caused an additional crosslink site through its unsaturation which led to increased crosslink density without phase separation of additive from the alkyd system which was confirmed by SEM scans.

The reactive additive, AGG used in the present study was synthesised using acryloyl chloride. Besides, it could also be synthesised from methacryloyl chloride and the effect of methyl substitution on water and solvent absorption could be studied.

The method developed provided a simple and practical solution to improving the mechanical properties of alkyd coatings.

The method for enhancing mechanical properties of cured alkyd system was novel and could find numerous applications in surface coatings.

The purpose of this paper is to study the effect of acrylated guar gum (GG) compared with GG in acrylic emulsions with reference to its viscosity, film properties such as mechanical strength, weathering properties and clarity.

The acrylate derivatives were synthesised and characterised and then incorporated in acrylic emulsions and their rheology studied. Films were analysed for their clarity and mechanical properties. The films were then subjected to UV radiation and the influence of these additives on the weathering properties was studied.

The viscosity of acrylated GGs in emulsions was lower than that of GG in emulsion because of the increased hydrophobic nature and hence reduced water‐binding capacity. The mechanical properties of acrylated GGs were superior compared with GG due to increased compatibility of the additive with the polymer binder. This was further confirmed with increased clarity of the films. Acrylated GG was found to act as a protective additive with reference to UV degradation of the coatings.

The performance of these additives was analysed on un‐pigmented coating formulations, which may not conform with pigmented coatings.

These biodegradable additives synthesised from renewable resources could be used to increase the mechanical strength as UV stabilisers and in some cases also as rheology modifiers.

The use of acrylated polysaccharides to increase mechanical and weathering properties allows the use of biodegradable, renewable resources as opposed to petroleum‐based compounds.

The purpose of this study is to modify guar gum (GG) into guar gum acetate (GGA) and phthaloyl guar gum (PHGG) by transesterification and phthaloylation, respectively.

GG has been modified into GGA through transesterification reaction between GG and vinyl acetate and PHGG through esterification reaction with phthalic anhydride. The modified GG was characterized by solubility test, Fourier-transform infra-red (FTIR) spectroscopy, proton nuclear magnetic resonance (¹H NMR) spectroscopy, X-ray diffractometry (XRD) and thermogravimetric analysis. Swelling properties of GGA and PHGG hydrogels in water were evaluated.

These two types of modified GG have better solubility such as in dimethyl sulfoxide and N,N-dimethylformamide but no true organosolubility was achieved. The modifications were confirmed through FTIR with new absorption peaks at 1,733 cm⁻¹ for GGA and 1,709 cm⁻¹ for PHGG coupled with observed substitution peaks at 1.80 to 2.20 ppm and 7.40 to 7.90 ppm, respectively, from ¹H NMR spectroscopies. XRD revealed both GGA and PHGG are less crystalline than native GG. GGA was found to be more thermally stable than native GG, whereas PHGG was slightly less thermally stable than native GG. The swelling property in distilled water for native GG, PHGG and GGA was 918.43 ± 46.62%, 537.04 ± 2.87% and 393.04 ± 13.42%, respectively.

The GGA and PHGG hydrogels are expected to be useful for biomedical fields such as tissue engineering and drug-delivery.

Modifications of native GG into GGA using vinyl acetate and PHGG using phthalic anhydride are novel.

The purpose of this study is to investigate the authors' previously prepared and fully characterized poly (methacrylamide)-chitosan nanoparticles (CNPs) graft copolymer having 50.2% graft yield with respect to flocculation efficiency for ferric laurate aqueous dispersions. This was done to compare the ability of the latter cheap, biodegradable and ecofriendly hybrid natural-synthetic polymeric substrate as a flocculant in comparison with higher cost, nonbiodegradable and harmful polyacrylamide as a well-known synthetic flocculant counterpart.

The graft copolymerization process was carried out at 450°Cfor 120 min using (1.0 g) CNPs, methacrylamide (1.5 g), 100 mmol/l potassium chromate and 80 mmol/l mandelic acid. Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and specific viscosity were used to characterize and analyze the resultant copolymer. The flocculation efficiency was conferred in terms of transmittance % and weight removal %. The main factors influencing the flocculation process, such as flocculent dose, flocculation medium pH, stirring speed, flocculation temperature and grafting extent, were comprehensively discussed.

The flocculation efficiency of the prepared copolymers revealed the following findings: increased by increasing the flocculant dose, pH, temperature and stirring speed to a maximum values denoted at 30 ppm, 6.0, 30°C and 50 r/min, respectively, then decreased thereafter; increased by increasing the extent of grafting within the range studied; showed a comparable flocculation efficiency in comparison with polyacrylamide as a synthetic polymeric flocculent; and, finally, a preliminary bridging mechanism representing the attraction between the anionic suspended particles ferric laurate and cationic poly (MAam)-CNPs graft copolymer has been projected.

The advancement addressed here is undertaken with using the authors’ poly (MAam)-CNPs graft copolymers having different extent of grafting (a point which is not cited in the literature especially for the authors’ prepared copolymer) as a hybrid natural-synthetic polymeric substrate as a flocculant for ferric laurate aqueous dispersions in comparison with the high cost and nondegradable polyacrylamide synthetic flocculant.

A successful conference was held at the Sheraton Hotel, Frankfurt from 23rd to 25th October 1989. The title covered High Solids, High Build, High Performance and High Technology. 16 papers were presented by an international group of lecturers. Over 200 delegates from many countries attended, from as far away as Brazil, Japan, Israel, and surprisingly, both Iraq and Iran. A summary of papers follows:

Developments in the area of epoxy resins make rich contributions to the patent literature. The single subject on which more patents are issued than any other is curing agents. Accordingly, this section will describe some of the patents on epoxy resin curing agents that have been issued in the past few years. Associated with the curing agents are catalysts, coreactants, and modifiers.

The purpose of this paper is to develop a high-performance composite emulsion cement waterproof coating. The coating has excellent durability and is effective in protecting cement mortar substrates from harmful ions.

The polymer cement waterproof coatings with different emulsion compounding ratios were tested for mechanical properties and water resistance after alkali immersion, water immersion, thermal aging and UV aging, and the coatings were analyzed by infrared spectroscopy after aging to evaluate its durability. Meanwhile, the coating that presents favorable durability was applied to cement mortar test blocks. The protective effect of the coating on the test blocks was tested by immersion method, and X-ray diffraction analysis was performed on the eroded test blocks.

The coating with neoprene latex/acrylate latex weight ratio of 90/10 presents favorable durability and has superior overall performance. Besides, when it is applied to cement mortar blocks, the coatings effectively reduced the erosive effect of harmful ions on cement mortar blocks, resulting in much lower mass change ratios and less internal structural damage of the blocks significantly.

The obtained coating will be of great application potential for use in building waterproofing construction. Moreover, the coating can practically prevent chloride ions and sulfate ions from penetrating cement-based materials.