Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Copper Replaces Tin: A Copper based Gelling Catalyst for Poly-Urethane
  from Discarded Motherboard   A discarded motherboard based eco-friendly copper catalyst has been
programmed to replace the industrially used tin based catalyst DBTDL. The
catalyst has been characterized by UV-Vis spectroscopy, FT-IR and TEM. Using
the catalyst reaction conditions is optimized and under the optimized
condition, both polyurethane and polyurethane foam are prepared, thus proving
the generality of the catalyst to be used in industries. A possible mechanism
has also been proposed.

32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex