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PVC - one of the world's most valuable and widely used plastics,
is sensitive to heat degradation, and requires heat stabilizers
for processing. Most of the heat stabilizers not only have metals,
but are also based on heavy metals like lead, cadmium etc. These
metals have a tendency to leach out in the soil and pollute it.
Besides, some of them are not safe to be used in contact with food
products. The PVC industry is facing a challenge from environmentalists
to continuously reduce or eliminate these heavy metal products.
Some of the developed regions have taken a forward step in limiting
and phasing out usage of heavy metals gradually in the next few
years. However, the alternatives developed so far are either more
expensive or do not function adequately. There is an increasing
trend of shifting from lead and cadmium to less heavy metal products
like calcium, zinc or tin. Efforts are underway to develop heat
stabilizers that are entirely organic While some organic products
are already commercialized, these groups are yet to become competitive.
Recently patented organic PVC stabilizers, can make PVC safer and
more versatile. The technology employs unique organic compounds called
ester thiols as heat stabilizers in PVC. These compounds are compatible
with vinyl polymer and can also serve as plasticizers when used at
high levels. Their dual usage benefit as both stabilizers and plasticizers
could make ester thiols a near perfect solution for certain problems
associated with PVC.
These products are expected to be commercialized by Edison Polymer
Innovation Corporation (EPIC) in Ohio, USA. There has been significant
interest in this innovative product as a stabilizer and as a plasticizer
from major speciality chemical companies.
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