NYLON

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NYLON

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  • 1. OTHER NAMESPolycaprolactamPolyamide 6PA6Poly--caproamidePerlonCapronUltramidAkulonNylatronKapronAlphalonTarnamidAkromidFrianylSchulamidDurethanMolecular formula (C6H11NO)nDensity 1.084 g/mLMelting point 493 KNYLON 6

2. PPRREEPPAARRAATTIIOONN OOFF NNYYLLOONN 66Nylon 6 is prepared from -caprolactam in the presence ofwater (which acts as catalyst) and acetic acid as a molecularweight regulator.The typical combination is charged into the vessel and reactedunder a nitrogen blanket at 250C for about 12 hours . 3. MMAANNUUFFAACCTTUURRIINNGG OOFF NNYYLLOONN 66 The schematic diagrams of the continuous polymerization of -caprolactam to produce Nylon 6 is illustrated on the side. The so called VK tube is used in the polyamide process. Reactive end groups are formed by hydrolysing the caprolactam to amino caproic acid . A lactam melt with a relatively high water content (15%) is fed tothe top of the VK tube equipped with a stirrer and heating coil. The water vapourises at the top , when viscosity is still low , togive a residue of the desired composition. In the lower part of the tube , the equilibrium degree ofpolymerization is reached with an increasing viscosity of the melt. The polymer is drawn off at the bottom and granulated. Its equilibrium content of caprolactam and oligomers is about10% at a final temperature of 270 C.. The monomer and oligomers are extracted from the chips withhot water, and the polymer is subsequently dried with hot gas in aventricle cylinder hot dryer. Intensive drying can produce a further reaction in the solid stateand according to the polycondensation equilibrium a higher degreeof polymerization reached . 4. RREELLAATTIIOONNSS OOFF SSTTRRUUCCTTUURREE AANNDDPPRROOPPEERRTTIIEESS In polyamides such as Nylon 4,6 , 6,6 , 6,10 and 11 contain polar CONH- groupsspaced out at regular intervals so that the polymer crystallize with a highintermolecular attraction . These polymer chains also have aliphatic chain segmentswhich give a measure of flexibility in the amorphous region. The combination of high inter chain attraction in crystalline zone and flexibility in theamorphous zone leads to polymer which are tough above their apparent glasstransition temperature. The high intermolecular attraction leads to polymers of high melting point. Howeverabove the melting point the melt viscosity is low because the polymer flexibility at suchhigh temperatures , which are usually more than 200C above the Tg and the relativelylow molecular weight. Because of high cohesive energy density and their crystalline state the polymers aresoluble only in a few liquids of similar high solubility parameter which are capable ofspecific interaction with the polymers. The electrical insulation properties are quit good at room temperature in dry conditionsand at low frequencies . Because of the polar structure they are not good insulators forhigh frequency work and since they absorb water they are also generally unsuitableunder humid conditions. 5. SSTTRRUUCCTTUURRAALL VVAARRIIAABBLLEESS AAFFFFEECCTTIINNGG TTHHEEPPRROOPPEERRTTIIEESS The distance between the repeating CONH- group :As a rule higher the amide group concentration i.e. the shorter the distance betweenCONH- group , the higher the: Density Forces required to mechanically separate the polymer molecules and hence the higher the tensile strength,rigidity, hardness and resistance to creep. The Tm and heat deflection temperature Resistance to hydrocarbon Water absorptionNylon 11, has twice the distance between amide group of that in Nylon 6, andsubsequently is intermediate in properties between Nylon 6 and polyethylene. The number of methylene groups in the intermediates:Even number of methylene groups have higher melting points than similar polymers withodd number of methylene groups .Nylon 6,6 has a higher melting point than either nylon 5,6 or nylon 7,6. With polymersfrom amino acids and lactams i.e. among nylon 6,7 and 8 it is found that Nylon 7 (227C)has higher meltingpoint than either Nylon 6(215C) or Nylon 8(180C).These differences are due to the differences in the crystal structure of polymers with oddand even methylene groups which develop in oder that oxygen atoms in one molecule are adjacent to aminogroup of a second molecule.Hydrogen bond with NH-O distance 2-8 are produced and the reason for the highstrength and the high melting point of polyamide such as Nylon 6, 66 &7. 6. The molecular weight: Specific type of Nylon,e.g.66 are frequently available in formsdiffering in molecular weight. The main differences between suchgrades is in melt viscosity, the more viscous grades being moresuitable for processing by extrusion techniques. N-substitution : Replacement of the hydrogen atom in the CO-NH- groups as CH3 and CH2OCH3 will cause a reduction in the inter chainattraction and a consequent decrease in softening point. Rubberyproducts may be obtained from methoxy methyl Nylons. Co-polymerization: Co-polymerization as usual, leads to less crystalline and frequentlyamorphous materials . These materials as might be expected ,are tough leather like , flexible and when unfilled reasonallytransparent. 7. Attacked by strong acids ,phenols, cresols atelevated temperatureHigh temperature resistanceLow co-efficient of linear thermal expansionHigh water absorptionFatigue resistanceGood drawabilityCreep resistanceGood appearanceGood moulding economies 8. OTHER NAMESPoly(hexamethylene adipamide)Poly(N,N-hexamethyleneadipinediamide)MaranylUltramidZytelAkromidDurethanFrianylVydyneMolecular formula - (C12H22N2O2)nDensity 1.14 g/mL (zytel)Melting point - 542K 9. PREPARATION OF NYLON 66 The Nylon 66 is prepared from Nylon salt(prepared by reacting the hexamethylene diamineand adipic acid in boiling methanol. Thecomparatively insoluble salt precipitate out frommethanol.) A 60 % aqueous solution of the salt is then run intoa stainless steel autoclave together with a trace ofacetic acid to limit the molecular weight (9000-15000). The vessel is sealed and purged with oxygen freenitrogen and the temperature raised to 220 degreecelsius. A pressure of 1-7 MPa is developed. After 1-2 hours the temperature is raised to 270-280 C and steam blend off to maintain the pressure1.7 MPa. The pressure is then reduced to atmospheric forone hour , after which the polymer is extruded byoxygen free nitrogen on to a water cooled castingwheel to form a ribbon which is subsequentlydisintegrated. 10. MANUFACTURING OF NYLON 66 The polymerization of nylon 66 iscarried out in several differentreactors connected in series . The starting material is an aqueoussolution of Nylon salt (AH salt)containing equivalent quantities ofhexamethylene diamine and adipicacid . The solution with about 60% solidcontent is fed in to the first horizontalcylindrical reactor then divided in toseveral components where the wateris drawn off as vapour andprecondensate of low molecularweight is formed. 11. This is pumped in to the second reactor , whichis a heated tube reactor with a graduallyincreasing diameter. Polycondensation proceedshere and vapour forms at falling pressure. The next step is the removal of water in asteam seperator followed by feeding the polymermelt by means of a screw conveyor in to the lastreactor,which consists of a heated screw conveyorwhere water vapour is again withdrawn and thefinal poly-condensation equillibrium is attained . 12. BUSSINESS EQUIPMENTBussiness machinesVending machinesOffice equipmentCONSUMER PRODUCTSKitchen utensilsToysSporting goodsApparel fitmentsPersonal accessoriesPhotographic equipmentMusical instrumentsBrush bristlesFilm for cookingFishing line 13. ELECTRICALIndustrial controlsWiring and associated devicesIndustrial connectorsBatteriesTelephone partsSwitchesHARDWAREFurniture fittingsDoor and window fittingsToolsLawn and garden implementsBoat fittings 14. MACHINERYAgriculturalMining and oil drillingFood processingPrintingTextile processingEngine partsPumps, valves, meters, filtersAir blowersMaterial handling equipmentStandard componentsGearsCamsSprocketsBearingsGasketsPulleysBrushes 15. APPLICATIONS OF NYLON 6 & 66 16. MANUFACTURERS OF PA 6 & PA 66Monsanto St.LouisBayers Corpn. PolymersBASFDupont India Pvt LtdSri Ram Fibers(SRF)Tipco Industries LtdVimar International India (P)LtdDilip Plastics (p)ltdKa Bee AgenciesProfessional plastics industries 17. BiodegradationFlavobacterium sp. [85] and Pseudomonas sp. (NK87)degrade oligomers of Nylon 6, but not polymers. Certain whiterot fungal strains can also degrade Nylon 6 through oxidation.Biodegradable Polymers aass DDrruugg CCaarrrriieerr SSyysstteemmss Natural Polymers Remain attractive because they are natural products of livingorganism, readily available, relatively inexpensive, etc. Mostly focused on the use of proteins such as gelatin, collagen, andalbumin 18. NYLON COMPOSITESNylon can be used as the matrix material in composite materials,with reinforcing fibers like glass or carbon fiber; such a composite has ahigher density than pure nylon. Such thermoplastic composites (25% to 30% glassfiber) are frequently used in car components next to the engine, such as intakemanifolds, where the good heat resistance of such materials makes them feasiblecompetitors to metals.AEROSPACE APPLICATIONFor aerospace applications requiring specific surface properties,composites from UHMWPE, para aramid,carbon, glass, nylon, polyester, andmost other engineering fibers are used.These materials maintain a significant advantage over traditionalmaterials, such as those made from polyester or nylon, whose strength-to-weightratios are too low for advanced aerospace applications. 19. Cellulose Fiber Reinforced Nylon 6 or Nylon 66 CompositesCellulose fiber was used to reinforce higher melting temperature engineeringthermoplastics, such as nylon 6 and nylon 66.The continuous extrusion direct compression molding processing andextrusion-injection molding were chosen to make cellulose fiber/nylon 6 or66 c