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TMI Blog1985 (5) TMI 221X X X X Extracts X X X X X X X X Extracts X X X X ..... be seen from his order No. 2316/80, dated 22-12-1980. 2. The appeal before us was heard on 25-3-1985. The counsel for M/s. Epochemick reiterated the arguments made before the Assistant Collector and the Appellate Collector that this was not a condensation product and gave the definition of what a condensation product was. It was a reaction in which polymers are formed with resultant by-products like water or alcohol, etc. In the reaction to produce these goods, no by-product was formed or spilt out. 3. Most authorities agree that separation of water or other byproduct results from the condensation polymerization to form polymers. But there are authorities contrary to Epochemick s assertions which hold that the formation of a side product is not always necessary for condensation polymerisation to take place. This is how condensation is described in GLOSSARY OF CHEMICAL TERMS Second Edition (Clifford A. Hampel Gessner G. Hawley) A condensation polymer is a linear or three-dimensational macromolecule resulting from a catalyzed reaction between two organic molecules, often of the aldehyde or ketone type, usually with the formation of water or an alcohol as a byproduct. ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... to produce an epoxy-terminated molecule with two epoxide groups. 5. There are certain significant, passages in the TEXTBOOK OF POLYMER SCIENCE Second Edition (Fred W. Billmeyer, Jr.) which presents this reaction thus - The epoxy resin used most widely is made by condensing epichloro-hydrin with bisphenol A, diphenylol propane. An excess of epichlorohydrin is used to leave epoxy groups on each end of the low-molecular-weight (900-3000) polymer : Depending on molecular weight, the polymer is a viscous liquid or a brittle high-melting solid. 6. MODERN PLASTICS TECHNOLOGY (Raymond B. Seymour) explains epoxy resin by saying that glycidyl ethers are prepared by the condensation of epichlorohydrin and monofunctional phenol. The book says that the curing of the epoxy resin intermediate is sometimes called a condensation reaction, but this is also incorrect since the resinuous product is produced exclusively in the absence of any byproducts. The term step reaction polymerization is preferred. 7. There is an argument by M/s. Epochemick that their product diglycidal ether of bisphenol A is not a resin. They prepare a resin out of this by addition of a curing agent. T ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... n in the last part of the nineteenth century. 12. These authorities prove that the reaction that produced Gebriez 500 involved condensation. Therefore, M/s. Epochemick were in error when they say their goods was not a condensation product. The chief chemist also gave his opinion after testing the sample that the product was an epoxy resin. 13. The reference to the styrene monomer by the factory is irrelevant because this is not styrene ; the trade notice would not help in the assessment of this product. The party admits that it is an epoxide. The public notice concerning Polyol issued by the Madras Custom House has no relevance because the product here has a fixed chemical composition. Certain opinion of experts had been produced; one is written by Dr. S.R. Ramadas, Professor of Chemistry Indian Institute of Technology and the other by Dr. V. Thiagarajan, Professor and Head of the department of Chemistry, Ramakrishna Mission College but these are new evidences and cannot be accepted. However, she pointed out that in Dr. Ramadas s written opinion the last sentence runs thus - These compounds are classified simply as epoxy ethers or epoxides. This sentence completely ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... evant time, the central excise tariff item 15A did not list epoxide resins as it does now. Before 18-6-1977, the item covered - ARTIFICIAL OR SYNTHETIC RESINS AND PLASTIC MATERIALS AND ARTICLES THEREOF (1) Artificial or synthetic resins and plastic materials in any form, whether solid, liquid or pasty, or as powder, granules or flakes, or in the form of moulding powders, the following namely- (i) Condensation, polycondensation and polyaddition products, whether or not modified or polymerized, including phenoplasts, aminoplasts, alkyds, polyamides, polyurethane, polyallyl easters and other unsaturated polyster. (The rest of the item is not reproduced, as it is not relevant). 16. From 18-6-1979, item 15A underwent a change although the essential contents remained the same. For our purpose, the most important change was inclusion of epoxide resins in 15A(1) (i). The appellants argued that the goods fell outside 15A because under the old tariff item only condensation, polycondensation and polyaddition products could be included and since epoxy resins are not condensation nor addition polymerization products, they would not fall in this item. The counsel said that the Ch ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... uct, thermosetting resins. 20. The Chief Chemist confirms what we thought about this product, namely, that the diglycidal ether of bisphenol A is only an intermediate in the production of the epoxy resin. This intermediate has molecular weight from 890 to 2900, too low for a high polymer which is understood to be the basis for all artificial and synthetic resins of the type covered by item 15A of the central excise tariff. The CONDENSED CHEMICAL DICTIONARY (Gessner G. Hawley) describes a synthetic resin as a man-made high polymer resulting from the chemical reaction between two or more substances. It describes high polymer as an organic macromolecule composed of a large number of monomers. The molecular weight may range from about 5000 into the millions. It gives the dividing line between low and high polymers as being in the neighborhood of 5000 to 6000 molecular weight. The GLOSSARY OF CHEMICAL TERMS (Clifford A. Hampel and Gessner G. Hawley) defines a high polymer as a natural or synthetic polymer of high molecular weight i.e. 5000 or more. The book PLASTICS CHEMISTRY AND TECHNOLOGY (Walter E. Driver) explains in Chapter 2 that a molecular weight is customarily used to repr ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... d by the learned Mrs. Zutshi, there is a paragraph at page 155 thus - The Classical intermediate, and the one accounting for 85 % of all production of epoxy resins, is a diglycidyl ether produced by the gradual addition of sodium hydroxide to promote the condensation of more than 2 moles of epichlorohydrin and 1 mole of bisphenol A [2, 2 -bis (4-hydroxyphenyl) propane] at 60 o C. 27. This paragraph is significant for more reasons than one. The condensation that it speaks of here is not the condensation of polymerization but the condensation to produce the (diglycidyl) ether (of bisphenol A). The author regards this diglycidyl ether as the intermediate, accounting for 58% of all production of epoxy resins. 28. PLASTICS AND TECHNOLOGY by Walter E. Driver reports that epoxy resins give off no byproducts during cure. The most common types of an epoxy resins are made from bisphenol A reacted with epichloro-hydrin to produce an epoxy terminated molecule with two epoxide groups. The simplest form of bisphenol A epoxy has a molecular weight of 340. Since there are two epoxide groups, equivalent weight is 170. 29. PLASTICS MATERIALS (Brydson) tells us that the first and st ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... ED CHEMICAL DICTIONARY (Gessner G. Hawley) gives the manufacture of polymer as one of the uses to which an ether is put. 34. Having seen the above, we can now appreciate better the opinions given by the experts. Dr. Ramadas and Dr. Thiagarajan. Dr. Ramadas gives as his opinion that diglycidyl ether of bisphenol A (Gebirex 500) is not produced by condensation or polycondensation or addition polymerization and that it is useful as a monomer in the production of polymers or resins. These compounds should be classified simply as epoxy ethers or epoxides. Dr. Thiagarajan also says that in his opinion the reaction was a typical nucleophilic substitution reaction and that it produced diglycidyl ether of bisphenol A which is not formed by condensation reaction. He opined further that diglycidyl ether of bisphenol A was only an epoxy ether and was not a polymer formed by condensation reaction. 35. This opinion agrees with what we learn in TEXT BOOK OF POLYMER SCIENCE (Billmeyer, Jr.) that the most common epoxide monomer is epichlorohydrins which reacts with a bifunctional hydroxy compound such as bisphenol A, and finds further confirmation in MODERN PLASTICS TECHNOLOGY (Seymour) w ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... be a condensation to form the polymer, i.e. a condensation polymerization. This was not the reaction. 38. But we do not agree with M/s. Epochemick that condensation polymerization much result in splitting out or in the elimination of a byproduct (water, alcohol, etc). There are sufficient authorities to indicate that spliting out or elimination of byproducts does not always accompany or result from condensation polymerization, though such is frequently the case. We have already reproduced at the beginning of this discussion what several authorities say on this subject. Besides these, we have the ENCYCLOPAEDIA OF CHEMICAL TECHNOLOGY (Kirk-Othmer) Vol. 18. At page 747 it writes condensation or step-reaction polymerization, is entirely analogous to condensation of low molecular weight compounds in polymer formation, the condensation takes place between two polyfunctional molecules to produce a larger polyfunctional molecule, with the possible elimination of a small molecule such as water. The reaction continues until almost all of one of the reagents is used up; an equilibrium is established, which can be shifted at high temperatures by controlling the amounts of the reactants an ..... X X X X Extracts X X X X X X X X Extracts X X X X
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