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OTHER NAMESPolycaprolactamPolyamide 6 PA6Poly-ε-caproamidePerlonCapronUltramidAkulonNylatronKapronAlphalonTarnamidAkromidFrianylSchulamidDurethan

Molecular formula (C6H11NO)n

Density 1.084 g/mL

Melting point 493 K

NYLON 6

PREPARATION OF NYLON 6PREPARATION OF NYLON 6•Nylon 6 is prepared from ϵ-caprolactam in the presence of

water (which acts as catalyst) and acetic acid as a molecular

weight regulator.

The typical combination is charged into the vessel and reacted

under a nitrogen blanket at 250°C for about 12 hours .

MANUFACTURING OF NYLON 6MANUFACTURING OF NYLON 6• The schematic diagrams of the continuous polymerization of - ϵ

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 .ϵ

• A lactam melt with a relatively high water content (15%) is fed to

the top of the VK tube equipped with a stirrer and heating coil.

• The water vapourises at the top , when viscosity is still low , to

give a residue of the desired composition.

• In the lower part of the tube , the equilibrium degree of

polymerization 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 about

10% at a final temperature of 270 °C..

• The monomer and oligomers are extracted from the chips with

hot water, and the polymer is subsequently dried with hot gas in a

ventricle cylinder hot dryer.

• Intensive drying can produce a further reaction in the solid state

and according to the polycondensation equilibrium a higher degree

of polymerization reached .

RELATIONS OF STRUCTURE AND RELATIONS OF STRUCTURE AND PROPERTIESPROPERTIES

• In polyamides such as Nylon 4,6 , 6,6 , 6,10 and 11 contain polar –CONH- groups spaced out at regular intervals so that the polymer crystallize with a high intermolecular attraction . These polymer chains also have aliphatic chain segments which give a measure of flexibility in the amorphous region.

• The combination of high inter chain attraction in crystalline zone and flexibility in the amorphous zone leads to polymer which are tough above their apparent glass transition temperature.

• The high intermolecular attraction leads to polymers of high melting point. However above the melting point the melt viscosity is low because the polymer flexibility at such high temperatures , which are usually more than 200°C above the Tg and the relatively low molecular weight.

• Because of high cohesive energy density and their crystalline state the polymers are soluble only in a few liquids of similar high solubility parameter which are capable of specific interaction with the polymers.

• The electrical insulation properties are quit good at room temperature in dry conditions and at low frequencies . Because of the polar structure they are not good insulators for high frequency work and since they absorb water they are also generally unsuitable under humid conditions.

STRUCTURAL VARIABLES AFFECTING THE STRUCTURAL VARIABLES AFFECTING THE PROPERTIESPROPERTIES

The distance between the repeating –CONH- group : As a rule higher the amide group concentration i.e. the shorter the distance between

–CONH- 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 absorption Nylon 11, has twice the distance between amide group of that in Nylon 6, and

subsequently 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 with

odd number of methylene groups . Nylon 6,6 has a higher melting point than either nylon 5,6 or nylon 7,6. With polymers

from amino acids and lactams i.e. among nylon 6,7 and 8 it is found that Nylon 7 (227°C)has higher melting point than either Nylon 6(215°C) or Nylon 8(180°C).

These differences are due to the differences in the crystal structure of polymers with odd and even methylene groups which develop in oder that oxygen atoms in one molecule are adjacent to amino group of a second molecule.

Hydrogen bond with NH-O distance 2-8 Å are produced and the reason for the high strength and the high melting point of polyamide such as Nylon 6, 66 &7.

The molecular weight:• Specific type of Nylon,e.g.66 are frequently available in forms

differing in molecular weight. The main differences between such grades is in melt viscosity, the more viscous grades being more suitable for processing by extrusion techniques.

N-substitution :• Replacement of the hydrogen atom in the –CO-NH- groups as

CH̴ 3 and CH̴ 2OCH3 will cause a reduction in the inter chain attraction and a consequent decrease in softening point. Rubbery products may be obtained from methoxy methyl Nylons.

Co-polymerization:• Co-polymerization as usual, leads to less crystalline and frequently

amorphous materials . These materials as might be expected , are tough leather like , flexible and when unfilled reasonally transparent.

Attacked by strong acids ,phenols, cresols at

elevated temperature

High temperature resistance

Low co-efficient of linear thermal expansion

High water absorption

Fatigue resistance

Good drawability

Creep resistanceGood appearanceGood moulding economies

OTHER NAMES

Poly(hexamethylene adipamide)

Poly(N,N-

hexamethyleneadipinediamide)

Maranyl

Ultramid

Zytel

Akromid

Durethan

Frianyl

Vydyne

Molecular formula - (C12H22N2O2)n

Density – 1.14 g/mL (zytel)

Melting point - 542K

PREPARATION OF NYLON 66

• The Nylon 66 is prepared from Nylon salt (prepared by reacting the hexamethylene diamine and adipic acid in boiling methanol. The comparatively insoluble salt precipitate out from methanol.)

• A 60 % aqueous solution of the salt is then run into a stainless steel autoclave together with a trace of acetic acid to limit the molecular weight (9000-15000).

• The vessel is sealed and purged with oxygen free nitrogen and the temperature raised to 220 degree celsius. 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 pressure 1.7 MPa.

• The pressure is then reduced to atmospheric for one hour , after which the polymer is extruded by oxygen free nitrogen on to a water cooled casting wheel to form a ribbon which is subsequently disintegrated.

MANUFACTURING OF NYLON 66• The polymerization of nylon 66 is carried out in several different reactors connected in series .

• The starting material is an aqueous solution of Nylon salt (AH salt) containing equivalent quantities of hexamethylene diamine and adipic acid .

• The solution with about 60% solid content is fed in to the first horizontal cylindrical reactor then divided in to several components where the water is drawn off as vapour and precondensate of low molecular weight is formed.

• This is pumped in to the second reactor , which

is a heated tube reactor with a gradually

increasing diameter. Polycondensation proceeds

here and vapour forms at falling pressure.

• The next step is the removal of water in a

steam seperator followed by feeding the polymer

melt by means of a screw conveyor in to the last

reactor,which consists of a heated screw conveyor

where water vapour is again withdrawn and the

final poly-condensation equillibrium is attained .

BUSSINESS EQUIPMENTBussiness machines

Vending machinesOffice equipment

CONSUMER PRODUCTSKitchen utensils

ToysSporting goodsApparel fitments

Personal accessoriesPhotographic equipment

Musical instrumentsBrush bristles

Film for cookingFishing line

ELECTRICALIndustrial controls

Wiring and associated devicesIndustrial connectors

BatteriesTelephone parts

Switches

HARDWAREFurniture fittings

Door and window fittingsTools

Lawn and garden implementsBoat fittings

MACHINERYAgricultural

Mining and oil drillingFood processing

PrintingTextile processing

Engine partsPumps, valves, meters, filters

Air blowersMaterial handling equipment

Standard componentsGearsCams

SprocketsBearingsGasketsPulleysBrushes

APPLICATIONS OF NYLON 6 & 66

MANUFACTURERS OF PA 6 & PA 66

Monsanto St.Louis

Bayers Corpn. Polymers

BASF

Dupont India Pvt Ltd

Sri Ram Fibers(SRF)

Tipco Industries Ltd

Vimar International India (P)Ltd

Dilip Plastics (p)ltd

Ka Bee Agencies

Professional plastics industries

Biodegradable Polymers as Drug Carrier SystemsBiodegradable Polymers as Drug Carrier Systems

◦ Natural Polymers Remain attractive because they are natural products of living

organism, readily available, relatively inexpensive, etc. Mostly focused on the use of proteins such as gelatin, collagen, and

albumin

Biodegradation

Flavobacterium sp. [85] and Pseudomonas sp. (NK87) degrade oligomers of Nylon 6, but not polymers. Certain white rot fungal strains can also degrade Nylon 6 through oxidation.

NYLON COMPOSITES

Nylon can be used as the matrix material in composite materials,

with reinforcing fibers like glass or carbon fiber; such a composite has a

higher density than pure nylon. Such thermoplastic composites (25% to 30% glass

fiber) are frequently used in car components next to the engine, such as intake

manifolds, where the good heat resistance of such materials makes them feasible

competitors to metals.

For aerospace applications requiring specific surface properties,composites from UHMWPE, para aramid,carbon, glass, nylon, polyester, and most other engineering fibers are used.

These materials maintain a significant advantage over traditionalmaterials, such as those made from polyester or nylon, whose strength-to-weight ratios are too low for advanced aerospace applications.

AEROSPACE APPLICATION

Cellulose Fiber Reinforced Nylon 6 or Nylon 66 Composites

Cellulose fiber was used to reinforce higher melting temperature engineeringthermoplastics, such as nylon 6 and nylon 66. The continuous extrusion – direct compression molding processing and extrusion-injection molding were chosen to make cellulose fiber/nylon 6 or 66 composites. The continuous extrusion-compression molding processing can decrease the thermal degradation of cellulose fiber, but fiber doesn’t disperse well with this procedure. Injection molding gave samples with better fiber dispersion and less void content, and thus gave better mechanical properties than compression molding.

Low temperature compounding was used to extrude cellulose fiber/nyloncomposites. Plasticizer and a ceramic powder were used to decrease the processingtemperature. Low temperature extrusion gave better mechanical properties than hightemperature extrusion.

Nylon-6/Agricultural Filler Composites

According to plastic technology , Nylon-6 filled with 20 wt% of Curaua fibers were extruded and injection moulded without addition of any additives. Curaua give rise to modulus, strength and it is lighter than glass fiber. It has been claimed that Nylon-6 with 20 wt-% of this fiber has been used in frame of the sun visor in the car.

The other fibers which were blended with Nylon-6 are sugarcane bagasse .

It was found that melting point decreases by addition of fibers.

This is due to the partial miscibility of amorphous region of the Bagasse fiber in Nylon-6 and the probability that the Bagasse fiber changed the Nylon-6 crystalline size and structure or the presence of strong interfacial interaction between fiber and matrix.

In order to obtain composites with better mechanical

properties several modifications were done

The rheological analysis of sugarcane bagasse

fiber/Nylon-6 composites showed an increase in viscosity with

an increase in the fiber loading and length.

The mechanical properties of glass fiber and carbon fiber reinforced nylon 66 were investigated using both microscopic and macroscopic testing techniques.

The objective was to determine how different interphase morphologies affect the adhesion and properties such as damping, ultimate stress and strain, and modulus of the composite.

Interphase of nylon 66 composits

The specific interphase that forms in both glass reinforced and high modulus carbon fiber reinforced nylon 66 is termed transcrystallinity.

Additional techniques such as scanning electron microscopy, profilometry, thermogravimetric analysis,differential scanning calorimetry, and water absorption measurements were performed to assist in data interpretation.

CONDUCTIVE NYLON 6 NANOFIBER FOR MEDICAL APPLICATION

Conductive Nano fiber use in make of nerve matrix and help us for persuasion nerve with weak electricity flow to injured limb. Due to the high flexibility and high elongation nylon 6 and high strength nylon 6 in front of some chemicals such as acid and weak base chosen for the initial substrate and matrix.

Different ways is for used carbon nanotubes in the production of nylon 6 nanofibers .

In general, the methods employed in the production of carbon nanotube nano-fibers, nylon 6 is as follows: Using carbon nano-tubes before spinning Using carbon nano-tubes in spinning Using carbon nano-tubes after spinning

CONTINUOUS FIBER REINFORCED NYLONCOMPOSITES FOR STRUCTURAL APPLICATIONS

For applications that require a greater measure of structural strength, nylons (polyamides) are commonly employed. Many of these applications are satisfied with injection molded nylon parts. Advances in reinforced nylon materials have been utilized to build front end bolsters, seat pans, bumper beams, battery trays, gears, engine covers, and intake manifolds. While development of LFRT (long fiber reinforced thermoplastic) nylon technology has yielded improved properties and allowed higher load profiles, the development of CFRT (continuousfiber reinforced thermoplastic) nylon composites at Polystrand now allow us to approach applications previously only possible with either metal or thermoset composite construction.

"Nylon Composite Sheets"

The automotive industry is making increasing use ofhybrid technology (also known as plastic/metal composite technology) for the volume production of highly integrated structural parts that can withstand high stresses while still being light in weight.

Car roof frames are produced in polyamide using this technique.

Nylon composite sheet can easily be formed and draped after applying heat. Because thermoplastic processing does not trigger a chemical reaction, cycles are short and, most importantly, reproducible results can be achieved with extremely low scrap rates. Compared with metal, the investment needed to create a preform is much lower, as only one tool is needed.