Polycarbonate

Polycarbonate (PC) is known for its transparency, excellent resistance to impact and ability to withstand high temperatures during the lifespan of the final article.  But PC also has a few weaknesses, such as low chemical (gasoline) resistance, which is critical in automotive market applications.  High viscosity grades, necessary when high impact is required, have poor processability, which makes the injection molding of complex parts even more difficult.

Moreover, inherent properties of PC, such as impact resistance (especially at low temperatures), are also seriously compromised when colored pigments, fillers or flame retardant additives are used in the compound.

Recycled PC is increasingly a cost solution for compounders.  But these polymers, compared to the virgin resin, have weakened mechanical properties and therefore less impact resistance. Compounders therefore add impact modifiers to recycled PC in order to overcome the loss of impact induced by the recycling step.

In order to overcome some of these issues, we suggest two high performance impact modifiers based on two different technologies.

Benefits of Clearstrength^® Impact Modifiers in Polycarbonate

Exceptional Low Temperature Impact Performance
Clearstrength^® MBS impact modifiers allows PC, and particularly high flow PC, to achieve high impact performance at very low temperatures. As shown on the graph below, with loadings as low as 2%, Clearstrength^® E920 impact modifier will maintain complete ductile behavior of PC at 40°C.

Clearstrength^® E920 impact modifier's great low temperature impact performance: 

High performance impact modifiers based on butadiene rubber (ABS or MBS) are detrimental to the inherent UV and heat stability performance of polycarbonate. In weatherable outdoor applications or in high heat environments, it will be critical to use a very stable impact modifier that will provide high impact performance. Durastrength^® 440 impact modifier was designed to respond to this technical challenge. 

Polycarbonate aging performance improvement due to Durastrength^® 440 impact modifier:

Benefits of Durastrength^® 440 Impact Modifier in Polycarbonate

Durastrength^® 440 impact modifier was designed as one of the best acrylic impact modifiers on the market, capable of providing surprisingly high impact performance at very low temperatures.

High performance of Durastrength^® 440 impact modifier in polycarbonate at low temperatures:

Excellent Weatherability & Heat Aging
Durastrength^® 440 impact modifier provides the excellent weatherability expected of an all-acrylic impact modifier. This allows Durastrength^® 440 impact modifier to be used in applications that demand good color hold and retention of mechanical properties under typical outdoor exposure, yielding products that retain long-term performance under severe conditions.

Exceptional Mold-in Colorability
Durastength^® 440 impact modifier provides far superior colorability than most of the acrylic modifiers available on the market, which are known to lower color intensity thus making dark color parts difficult if not impossible to achieve. Durastrength^® 440 impact modifier, a patented technology, opens the door for applications that demand good color hold and exceptional mechanical propery retention upon exposure to the elements.

Durastrength^® 440 impact modifier provides excellent color hold: