UVI LIGHT STABILIZERS
Light stabilizers can be added to plastics to protect them from the degradative effects of
exposure to sun and weather. Polyolefins are susceptible to attack by ultraviolet light,
oxygen, moisture, and heat resulting in polymer brittleness, surface crazing, color
change and product failure.
There are three major classes of light stabilizers for polyolefins.
1. UV ABSORBERS
.....Typical examples are benzophenones and benzotriazoles. These are low cost,
effective stabilizers that function by the absorption of UV light. They are effective for
short-term exposures.
2. NICKEL QUENCHERS
.....are Energy Transfer Agents that function by “quenching” the excited state
of carbonyl groups formed during photo-oxidation and also through the
decomposition of hydroperoxides. These types of stabilizers are not in wide use
since they contain heavy metal, impart color to the final product, and are not as
effective as the HALS discussed in the next paragraph.
3 . HINDERED AMINE LIGHT STABILIZERS (HALS)
...are the most effective of the light stabilizers for polyolefins. Available in a
wide range of molecular weights and structures suitable for almost any application.
They can also perform as long-term thermal stabilizers (HATS). They function by
“trapping” free radicals formed during the photo-oxidation process.
Since all three stabilizer types function by different mechanisms, they are often used in
combinations which can be synergistic. For example, HALS are commonly used with
benzotriazoles to minimize color changes in pigmented systems.
All of the above stabilizers will function most effectively in the presence of an
appropriate base stabilization package containing both primary and secondary
antioxidants along with a residual catalyst neutralizer.
It is necessary to note that the gauge of the product, the geographic location of
exposure, and the chemical environment are among the crucial factors in determining
the amount of stabilizer needed for a particular application. Please consult with
Ampacet for recommended usage levels of the following products.
AMPACET HALS PRODUCTS
100600
-
Our most cost effective HALS, suitable for a wide range of polyolefin
applications (“NR/NH” type blend).
100654
-
High molecular weight HALS with low volatility and high migration
resistance.
Preferred for color critical applications such as
polypropylene fiber/carpet applications. (“NR” type)
100840
-
Better performance than 100654, but not as suitable in the most color
critical applications. Well suited for most PP fiber and agricultural film
applications (“NR/NR” type blend).
101690
-
Most recent HALS development. “NOR” type chemistry.
Currently being tested in mulch film applications against 100840 for
stability in a high chemical environment.
AMPACET UVA PRODUCTS
100977
-
A benzotriazole UV absorber. Designed for the protection of contents of
packaging materials from harmful UV radiation. FDA approved for
indirect food contact. 100645 is 100977 with AO (2500 ppm).
100325
-
Less costly, non-FDA version of 100977.
For more information, please contact Ampacet’s technical support team
at 888-822-7546 or 812-466-9828
Disclaimer: The information and recommendations contained in this document are based upon data collected by Ampacet and believed
to be correct. However, no warranty of fitness for use or any other guarantees or warranty of any kind, expressed or implied, is
made to the information contained herein, and Ampacet assumes no responsibility for the result of the use of the products and
processes described herein. This is an uncontrolled document and information may be out of date.