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Purpose: Alkyd resins constitute a very high proportion of conventional binders used in surface coatings. In order to enhance the quality of these alkyd resins methyl esters of rubber seed oil (MERSO) were used in the preparation of the resins. Methods: MERSO were obtained by in-situ alcoholysis of rubber seed. Alkyd resins having oil lengths of 45, 50 and 55% were prepared with MERSO, phthalic anhydride and glycerol using alcoholysis method. Lead (II) oxide and xylene were used as catalyst and refluxing solvent, respectively. The physico-chemical characteristics of the MERSO and the resins obtained were compared with the corresponding value of rubber seed oil (RSO) and its alkyd resins. Chemical resistance of the alkyd resins was also determined. Results: The acid value of the finished alkyd resins depends on the rate and extent of esterification. Iodine value of the alkyd shows that the level of unsaturation depends on the oil length of the resins. The free fatty acid (FFA) value (1.99%) of the MERSO was much lower than that of the RSO (9.54%). This supports the choice of methyl ester as a preferred alternative to the use of the raw RSO in alkyd resin preparation. All the alkyd samples were fairly resistant to brine, acid and water but poorly resistant to alkali. However, the MERSO alkyds were observed to have a better resistance than the RSO alkyd resins. The scratch/gouge pencil hardness shows that the hardness of the alkyd films decreases with the oil length.

Polymer-inorganic nanocomposites are a recently developed class of materials that have altered physical or chemical properties with respect to the pure polymer, inorganic host, or their micro- and macrocomposites. Lower generation (G0.0-2.0) polyamidoamine (PAMAM) dendrimer/sodium montmorillonite (Na-MMT) nanocomposites were synthesized in a solution-phase exfoliation adsorption reaction. These are the first reports of the G0.0/ and G1.0/Na-MMT nanocomposites and of a structurally-ordered G2.0/Na-MMT. The materials were characterized using powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). PAMAM characteristics at acidic and basic aqueous media were studied using capillary zone electrophoresis (CZE). Pseudospherical PAMAM dendrimers in aqueous medium attain a highly flattened conformation within the confined space between MMT sheets upon nanocomposite formation. The nanocomposite structure depends on the PAMAM generation and the starting dendrimer/organic composition. G0.0 always forms monolayer structures (d = 0.42 nm), while G2.0 forms monolayer structure, mixed phase, and bilayer structures (d = 0.84 nm) at lower, intermediate, and higher organic content, respectively, showing an interesting monolayer to bilayer transition. G1.0 showed an intermediate behavior, with monolayer to mixed-phase transition at the reactant ratios studied. This monolayer arrangement of PAMAM/clay nanocomposites is reported for the first time. Maximum organic contents of G0.0 monolayer and G2.0 bilayer nanocomposites were ∼7% and ∼14%, respectively. Gallery expansions were similar to those observed with linear polymer intercalates, but the packing fractions (0.31-0.32) were 2-3 times lower. At acidic pH, the nanocomposites forming only monolayer structures are obtained, indicating a stronger electrostatic attraction between MMT and protonated PAMAM, and these nanocomposites formed more slowly and were more ordered. Na(+) ions play a significant role in nanocomposite formation. At high pH, PAMAMs show high mobility, ζ potential, and surface charge densities due to Na(+) complexation in solution. FTIR data indicates that both Na-MMT and PAMAM structural units are preserved in the nanocomposites obtained.

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Rubber seed oil (RSO) was modified with different amounts of maleic anhydride, and RSO alkyds (50% oil length) were modified to various extents by the incorporation of different amounts of maleic anhydride and fumaric acid. All the resins were evaluated as water-reducible binders. Modification with maleic anhydride increased the acid and saponification values of RSO but reduced the iodine value. RSO modified with maleic anhydride exhibited lower amounts of volatile organic compounds (Ͻ20 g/L) than the corresponding RSO alkyds (34 -87 g/L). The alkyd samples were superior to the modified RSO in chemical resistance.

This study was aimed at the synthesis and characterization of alkyd from rubber seed/linseed oil blends. Different percentages of rubber seed oil were blended with linseed oil for the preparation of alkyd via condensation polymerisation of monoglyceride with phthalic anhydride. Physiochemical properties like colour, acid value, saponification value, iodine value, drying schedule, chemical resistance were evaluated for the different alkyd samples synthesized. The colour of the different samples was unaffected by blending. The acid values of the alkyds obtained were observed to be in the range of 8.59–10.1 mgKOH/g. The iodine values of the different alkyd samples prepared increased with increase in the percentage of linseed oil in the blends. The blends showed resistance to brine, water and acid. However, only some exhibited fair resistance to alkali. The intrinsic viscosity was also determined by extrapolation from Huggins and Kraemer viscosity relationship. The results showed that the alkyd resins synthesized from the blend of linseed and rubber seed oil showed favourable properties that make linseed oil good blending oil for the synthesis of alkyd resin.

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