Biochemical
and Biotechnology -
Utilisation of waste from Nylon 6 industries
Introduction
The waste obtained at the bottom of
the distillation tower used in caprolactum recovery
contains trapped caprolactum along with oligomers. After
segregating the capralactum rich waste and oligomer
rich waste, the caprolactum rich waste, which is soluble
in water at room temperature, is subjected to chemical
purification and distillation for recovery of caprolactum.
The oligomer rich waste containing both cyclic and linear
oligomers was found to be polymerisable to moderate
molecular weights under controlled reaction conditions.
This material is subjected to either homo and/or co-polymerisation
to produce different types of adhesives and coatings.
A specific quantity of Oligomer waste
consisting of cyclic and linear oligomer is taken in
a reactor to which a specified amount of water is added
and heated in a heating bath. Inert gas, preferably
Nitrogen is flushed into the reactor and the temperature
of the reaction is raised. After maintaining the temperature
for the desired period a weighed amount of Manomer I
is added. The reactor is heated up again to raise the
temperature to the desired level and maintained for
about 30 minutes. Subsequently a weighed amount of Manomer
II is added and the reactor is heated further for attaining
another desired level of temperature. The temperature
is maintained at this level for a specific duration
with or without vacuum so that the required copolymer,
Nylon 6 : Polyester or Nylon 6 & 66 is produced.
In the case of Homopolymerisation, nitrogen is flushed
through the empty reactor first followed by the addition
of oligomeric waste. The reactor is then fixed with
a stirrer and placed on a heating arrangement. Subsequently,
the reactor is charged with Oligomeric waste and heated
with continuous stirring. On attaining the desired temperature
in about 30 minutes and allowed to remain at this temperature
for a specific duration, homopolymer of desired molecular
weight is produced. The polymers as obtained by the
process described above have been tested for end use
application, particularly as hot metal adhesive by known
methods. The lap-shear and T-peel tests carried out
have demonstrated better adhesive strength which may
be attributed to the random structure of the prepared
polymers.
Special Features:
Conversion of oligomeric waste or
polymeric waste into a useful hot metal adhesive; Additional
step involving addition flow agents and/or plasticisers
as practiced in the conventional method is eliminated;
Reduction in production cost; Can be used for treating
oligomer or polymer waste from both caprolactum recovery
plant as well as nylon 6 processing units.
Prospective Users:
The method is useful for (i) Caprolactum
processing units for producing a valuable by-product
(ii) small/medium chemical industries for conversion
of nylon polymeric and oligomeric waste material to
a useful product.
Type of Technology:
Product
Status of IPR Protection:
Indian Patent Application no: 749/DEL/99
dated 18th May 1999 with the title "A Method for
Co-polymerisation & Homo-polymerisation of Oligomeric
Wastes obtained from Nylon - 6 production, and products
thereof ".
Status of Development:
Investigations have been carried out
in collaboration with Caprolactum processing industry.
Process has been developed for producing hot metal adhesive
The end product, viz., the hot metal adhesive has been
tested as per ASTM D1876-61T and found satisfactory.
Scaling up can be easily carried out. The process could
also be used for the production of moulding material
and coating materials for metals.
Requirement of
Raw Materials/Components:
Stainless Steel batch reactor having
a capacity of 800 kgs. with heating capacity upto 300
deg. Centigrade
Vacuum system to be fitted to reactor to provide pressure
of 0.1 mm Hg
High power stirrers
Requirement
of Utilities:
Electricity
Treated Water
Services offered
by Technology Transfer:
Know how manual including quality
control procedures
Process demonstration (on payment of Rs.30,000)
Consultancy
Contact for
more information
The Director
Foundation for Innovation and Technology Transfer
Indian Institute of Technology Delhi
Hauz Khas, New Delhi-110016
Tel : 91-011-26597167, 26857762, 26581013
Fax : 91-011-26851169
E-mail : mdfitt@gmail.com
