Initiators for CR-PP
Controlled rheology polypropylene (CR-PP) extends and improves the characteristics of polypropylene (PP). By adding specific organic peroxides to PP in an extruder, the molecular weight distribution of the PP can be narrowed and at the same time the average molecular weight can be reduced. This process is known as visbreaking and results in a decrease in melt viscosity of the PP and an increase in melt flow index (MFI). Applications for CR-PP include film, extrusion coating, fibers (spun bond and melt blown) and injection molding.
The latest generation of our organic peroxides for CR-PP is Trigonox® 301, which is very cost-effective and releases low amounts of volatile decomposition products. It has excellent organoleptic properties and has been approved for food contact applications by both BfR and FDA.
Initiators for HMS-PP
Due to its linear chain structure, polypropylene (PP) has low melt strength and lacks strain hardening behavior. This may result in problems in applications that require melt extension. With the help of Perkadox® 24, high melt strength polypropylene (HMS-PP) can be produced while adding no smell to the final resin. FDA food contact approval has been obtained for all HMS-PP applications, including microwavable foamed food trays.
Initiators for HMS-PLA
Polylactic acid (PLA) has a low melt strength and no melt elasticity due to its linear chain structure. This may result in problems in applications that require melt extension. Adding a unique organic peroxide, such as Trigonox 301, allows for long chain branches to be made and creates high melt strength PLA (HMS-PLA) without gel formation.
A masterbatch of Trigonox 301® on PLA is also offered under the name of Trigonox 301-40PLA. This HMS-PLA technology, patented by AkzoNobel, can be used for foaming, thermoforming, blow molding, extrusion coating and cast and blown film applications.
Initiators for Maleic Anhydride Grafted Polymers
Polymers such as polyethylene (PE), PP and ethylene propylene diene terpolymer (EPDM) can be grafted in an extruder with maleic anhydride using specific organic peroxides. When separately dosing organic peroxide and maleic anhydride, the choice of organic peroxide depends on its solubility in the polymer and extrusion temperature applied. AkzoNobel offers various organic peroxides which can be used for this separate dosing technique.