Alkyd resin 17 oil207

Synthesis of Alkyd Resin and there process

1. Alkyd Resin Presented By, Dinesh More 17OIL207

2. Alkyd resin is a condensation polymerization reaction by which Polybasic acid reacts with polyhydric alcohol Alkyds are essentially short-branched polyesters formed by poly condensation of a dibasic acid and a polyhydric alcohol in the presence of the glycerides oil or oil derived fatty acids The alkyd resin was one of the first applications of synthetic polymers in surface coatings technology: it was successful in chemically combining oil or oil-derived fatty acids into a polyester polymer structure. Benefits of alkyd were the enhancement of the mechanical properties, drying speed and durability of the product. Alkyd Resin

3. Oil Length The amount of oil in an alkyd resin is the biggest single variable in the properties of an alkyd. The percentage of oil present in the resin expressed as triglyceride. Long oil length alkyds -contain more than 60% oil Medium oil length alkyds -contains 40-60% of oil Short oil length alkyds -contains less or up to 40% oil Classification of Alkyd Resins

4. Polyhydric alcohol Polybasic acid Triglyceride oil/monobasic fatty acid Monobasic acids Raw Materials

5. Alcoholysis Acidolysis Fusion Process Solvent Peocess Alkyd Manufacture

6. Preparation of Alkyd Resin Oil modified alkyd resin was prepared with dehydrated castor oil, glycerol and phthalic anhydride using NaOH catalyst. The preparation was done in a 4-neck round bottom flask fitted with a motorized stirrer, a nitrogen inlet, a thermometer pocked and a hold for sampling. Alcoholysis

7. Monglyceride Process

8. In this stage, monoglyceride was first prepared by reacting the oil with glycerol. Alcoholysis of oil was carried out with PbO catalyst and ( NaOH,KOH,LiOH ) catalysts. In alcoholysis reaction, the oil was heated with agitation speed of (700 rpm) and N2 sparging to 230-240˚C. Glycerol and selected catalyst was added and alcoholysis reaction was carried out at 230-240˚C. The reaction was continued until a sample of the reaction mixture became soluble in two to four volumes of anhydrous methanol. After alcoholysis reaction was completed, the reaction mixture was cooled to 140˚C. Stage 1 ( alcoholysis ):

9. In this stage, phthalic anhydride was added to the monoglyceride mixture. The temperature was maintained at the range of 230-240˚C and maintained at this temperature. The sparging rate of N2 was increased. The reaction was monitored by periodic determination of the acid value of the mixture until acid value dropped to nearly 5. Stage 2 (esterification):

10. Fatty Acids Process As the name itself indicates, this process uses the fatty acids derived from oils. Fatty acids separated from oil are used and not as such oil is used. Since fatty acids contain carboxylic group, they easily react with polyol and so there is no need to carry out alcoholysis or acidolysis of oil. Thus fatty acid, polyol and dibasic acid are together charged directly and polycondensation is carried out to produce alkyd resin. Fatty acids are expensive as compare to oils but they facilitate shorter process time and better products. To make it cost effective generally a mixture of fatty acids and oil is frequently used. Fatty Acid Process

11. all the raw materials are added at once and heated to 220-240 o C. Branched alkyds are produced. polyhydric alcohol and polybasic acid are allowed to react first at 180 o C to yield glycerol phthalate which is a clear viscous resin. mixture fatty acids are added and reaction temperature is increased to 220 o C. Linear alkyds are produced. fatty acids are added in step-wise manner from 40-90%, at 180-220 o C. Addition of fatty acids stepwise gives a polymer of high molecular weight by reducing the chain terminating reactions. Fusion method

12. This process is widely used in alkyd resins manufacture as it has many advantages over fusion process. In this process reactants are heated together at temperature between 200 oC - 240°C with a solvent (most commonly used solvent is Xylene) which helps in many ways during the process. The solvent and water of reaction form an azeotropic mixture which is distillated off from the reactor; condensed and passed into a separator where water is removed as waste and solvent is recycled to reactor. This will also result in short process time without encountering higher temperature. Solvent Process

13. Equipment for solvent processing of alkyd resins (Solv –Xylene) Alkyd Reactor

14. Alkyd resins are important ingredients in many synthetic paints, varnishes and enamels and find also applications as thermosetting plastics that can be molded . Architectural coatings , product finishes , special-purpose coatings and automotive refinishing primers. . The principal applications are highway traffic paints, concrete floor, and swimming pool paints. modified silicon resins include heat-resistant paints, and marine coatings and insulation varnishes, Cellulose nitrate APPLICATIONS