EPOXY RESINS

VARADA SUJEETH - B130345CH

VARRI SRINU - B130460CH

YEDUKRISHNAN M - B130328CH

EPOXIDES

• Epoxides - cyclic ether with three ring atoms

• Epoxide group -

• Addition of an oxygen atom across a C=C - Epoxidation

• Oxygen transfer agents – H2O2 , HOCl etc.

EPOXY RESINS

• Reactive polymers/prepolymers which contain epoxide groups

• Can undergo crosslinking reactions (referred to as curing ) with itself or amines , acids , phenols to give co-polymers.

• Uses – structural adhesives , metal coatings , electronic and electrical components , electrical insulators , plasticizers of vinyl polymers.

RAW MATERIALS

• Raw materials are mainly petroleum derived.

• Epichlorohydrin prepared using plant derived glycerol.

• Novolac epoxy resin – phenols , formaldehyde , epichlorohydrin

CHEMICAL REACTIONS

• Epoxy monomers – can be obtained from unsaturated compounds such as vegetable oils (natural) or butadienes (synthetic).

• Molecular structure of the polymer is usually complex

PROPERTIES

•Chemical stability – due to ether linkages

•High reactivity – epoxy/hydroxyl groups

• Excellent adhesion to surfaces

•Outstanding electrical properties – industrial applications

•Ability to form co-polymers with various applications

METHODS OF PRODUCTION

• Epoxy polymers are manufactured largely in a batch processing because of low tonnage, multiple formation marketing.

• Increase the demand of several epoxy resins has led to the development of continuous processing, using two or more mixing reactants in series

• Epoxy polymer process has relatively simple and use the solvent polymerization method.

FLOW DIAGRAM

PROCESS DESCRIPTION• Conversion of bis phenol and epichlorohydrin to an intermediate

product chlorohydrin in the presence of anionic catalyst.

• A portion of this product reacts with an sodium hydroxide to form a solid salt suspended in a liquid mixture comprising a dehydrogenated product and unreacted chlorohydrin intermediate.

• Alkali hydroxide is used at less than a stoichiometric amount and removing water and epichlorohydrin as a vapor from the reacting mixture; separating the solid salt from the liquid mixture; reacting at least a portion of the unreacted chlorohydrin intermediate with an sodium hydroxide in the presence of water to form an organic mixture comprising an epoxy resin and unreacted epichlorohydrin and an aqueous solution comprising a salt.

ENGINEERING PROBLEMS

• Safety precautions in handling the peroxide compounds to avoid detonating conditions.

• Exact temperature control with provisions for rapid dumping and water flushing for a runaway reaction.

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