Michele Raymond (michele@raymond.com)
Mon, 12 Apr 1999 10:22:12 -0400

OLYETHYLENE: Recyclable Crosslinked Polyolefin Pioneered
JCW April 9, 1999

Mitsubishi Chemical has begun shipping samples
of what the company claims to be the world's first
recyclable, heat-reversible, silane-crosslinked
resin. The product, created mainly from high-density
polyethylene, demonstrates the physical properties of
crosslinked resin at temperatures up to 150 C while
realizing melt-molding characteristics when heated to
230 C.
Linear polyolefins are known to significantly
increase their thermal, mechanical, and chemical
characteristics when crosslinked into net mesh
structure. However, the inability to recycle such
crosslinked polyolefins through melt molding or other
means has impeded their market diffusion.
Mitsubishi Chemical previously has
commercialized a crosslinked resin at low cost and
with excellent molding characteristics in which water
has reacted with an active silane group within the
polymer to form crosslinking. For some time the
chemical powerhouse has grappled with the challenge
of improving the basic properties of crosslinked
resins to allow recycling through melt molding.
By controlling polymerization conditions,
Mitsubishi Chemical has successfully formulated an
original technology for manufacturing crosslinked
polyolefin resin high in physical properties and
capable of melting at 230 C. The company has priced
samples at $5-6/kg and aims to turn this into a full-
blown business within two years.
Crosslinked polyolefin is used in a broad range
of industrial fields, from automotive applications to
sheathing for electrical wires and cables. The
annual market in volume terms is estimated at over
80,000 t/y.

Michele Raymond
Recycling Laws International/ State Recycling Laws Update
5111 Berwyn Rd. Ste 115 College Park, MD 20740)
301/345-4237 Fax 345-4768