Nylon is an important synthetic material for industrial purpose. It has many variants like Nylon 66, Nylon 6, Nylon 5,10, Nylon 6,12, Nylon 11 etc. What to choose, a little bit confusing right? Find out the differences between Nylon 6 and Nylon 66 right below!!
You will get to know about nylon 6, nylon 66 along with their application area in brief in this article.
For High mechanical damping ability, good sliding properties, excellent wear resistance, good electrical insulating properties, and good resistance to high energy radiation Nylon becomes incredibly popular for different industrial purposes.
A quick glance on the difference between Nylon 6 and Nylon 66
Basically main difference between Nylon 6 and Nylon 66 is in their chemical structure. Both of them are popular for their durability and light weight properties. Nylon 6 is formed from Caprolactum by open ring polymerization having lower melting point.
Whereas, Nylon 66 is formed from Hexa methylene di-ammine and Adipic acid by condensation polymerization reaction having a higher melting point. The latter property makes it suitable for high performance industrial use.
Nylon 6 in brief!
Nylon 6 results from open ring polymerization of only one monomer caprolactam. It is called Nylon 6 because of containg 6 carbon atioms in it. This is made from the type ………AAAAAA……… or (A)n, where n=200.
It provides good insulation and damping properties. Toughness, stiffness and hardness all of them are the characteristics of nylon 6. It has lustrous finish along with it exhibits good dye affinity.
Uses of Nylon 6
- Industrial yarn
- Heavy duty fabric
- Toothbrush fiber
What is Nylon 66?
Nylon 66 is a polymer formed from condensation polymerization of Hexa methylene di-ammine and adipic acid. It contains 12 carbon atoms that comes from its two monomers. As each of them has 6 carbon atoms in their structure.
Uses of Nylon 66
Its micro denier form is mostly used in apparel such as industrial workwear. Heavy denier is used in-
- Tire cord
- Automotive air bags
Properties of Nylon 6 and Nylon 66
Let’s have a general discussion on the properties of Nylon 6 and Nylon 66……
The numbers of repeat units along the polymer chains of nylon 6.6 and nylon 6 are about 65 and 130, respectively. Both types of nylon contain weakly basic amino and weakly acidic carboxylic acid end groups.
Nylon 6 and nylon 6.6 are strong fibers with moderate elasticity, even after drawing. Nylon 6 has a somewhat lower elastic modulus and better elastic recovery than nylon 6.6 and therefore gives more flexible fabrics of softer handle.
Both nylons are available in high tenacity variations for industrial uses. In fact, the mechanical properties can be varied considerably by changes in the polymerization and drawing conditions.
Heat setting of nylon materials may be carried out under dry conditions in hot air at 190 °C for nylon 6, or 205 °C for nylon 6.6. Alternatively, setting is achieved in steam at 120 or 135 °C, respectively.
At higher temperature like 180°C, Nylon 66 shows better heat age strength of 11.5 kg whereas Nylon 6 breaks down at 2.5 kg. The fibers of Nylon 66 are 33% more resistant to abrasion than Nylon 6. They can withstand 60,000 cycles while Nylon 6 can withstand 40,000 cycles at the same conditions.
Low creep, more crystalinity makes it slightly stiffer and better equipped, again its good stretch recovery, and higher abrasion resistance makes Nylon 66 more suitable for industrial use.
As Nylon 6 is a bit lustrous than Nylon 66, it is suitable for radiator grilles, stadium seats or firearm components where we need an attractive lustrous finish.
Differences between Nylon 6 and Nylon 66 in detail!!
|No. of carbon atoms in structure
|No of carbon atoms are 6. It represents that it has 6 carbon atoms in the backbone of its chain
|Nylon 66 has two 6 numbers. It indicates the number of carbons in the acid and ammine residues. So it has 12 carbon atoms.
|Requirement of monomer
|Only one monomer is required
|Two monomers are required
|Hexa-mythelene di-amine and Adipic acid
|It is known as poly-caprolactam which is formed by open ring polymerization
|This polyamide is formed by condensation polymerization
|Water absorption rate
|Chemical resistance to acid
|Heat deflection temperature
|Poly (6-aminocaproic acid)
|Poly [Immino (1,6-dioxohexamythelene)immio hexamythelene]
|Degree of polymerization
|More recyclable than nylon 66
|Less recyclable than nylon 6
|6.2 × 104 kPa
|8.3 × 104 kPa
|Glass transition temperature (Tg)
|Dry – 60Tg reduces with the increase in moisture content
|Dry – 70
|Less than nylon 66
|Great dye affinity
|Shows less dye affinity than nylon 6
|Less than nylon 66
|Heat setting at hot air
|Heat setting at steam
|Radiator grilles, stadium seats or firearm components
|Friction bearings, battery modules, luggage and conveyor belts
|Lower than nylon 6
|More lustrous surface
|Less lustrous surface
To Sum Up!!
So, what should you choose for your specific purpose? You will clearly get your answer if you understand the differences between nylon 6 and nylon 66.
Check out our another article on Nylon- not the material only for fiber!!
Salma Hasin the author of this site completed her BSc. in Textile Engineering (Wet Processing Engineering). She wants to share her knowledge to help students in their studies and businessman & entrepreneurs in their businesses in making wise decisions fast.