|
Polymer blends are expected to grow well in the future as no new
polymers are being developed. Polymer blends are used when two different
polymers that may not be compatible with each other are required
to obtain a balance of properties. For instance, Polyolefins are
low cost polymers but do not have adequate barrier properties. They
are often blended with Polyamides to enhance the barrier properties.
Compatibilizers are those products that allow blending of two immiscible
polymers creating a homogeneous mixture. A compatibilzer works like
a surfactant, lowering the interfacial tension between two incompatible
polymers, thus allowing them to mix. The blends may continue to
have two different phases but behave as if they are miscible. The
compatibilizer usually has two parts so that each part can interact
with the respective polymer in the blend.
There are essentially two type of compatibilizers :
 |
Reactive |
|
Non reactive |
Reactive compatibilizers develop covalent
bonds while non-reactive compatiblizers are typically miscible with
one of the polymers from the blend. A compounder should select the
compatibilizer that matches the polymers in the blend. Reactive
compatibilizers require a reactive counter group while non-reactive
compatibilizers should have good miscibility as well as good viscosity
match.
Some of the common compatibilizers are:
|
Copolymers of Ethylene with either EthyleneAcrylic Acid,
ButylAcrylic Acid or MethylAcrylic Acid |
|
Ethylene-butylacrylate-glicidyl methacrylate |
|
Maleic Anhydride grafted Polyolefins or SBS Copolymers |
|
Copolymers of PMMA or PS with PP |
From the above compatibilizers, copolymers are non-reactive while
Maleic Anhydride grafted and Ethylene-butylacrylate-glicidyl methacrylate
are reactive compatibilizers.
Crompton, Dexco, Dow, Dupont and Kraton are the major players in
the business of compatibilizers. It is estimated that the global
market of compatibilizers would grow more than 5% from the level
of 15 KT to about 18KT by 2005. All compounders can take the advantage
of these compatibilizers to enhance the value of their compounds.
|