Polyolefin Degradation Mechanics in Post-Consumer Resin Recyclate Streams
Polyolefin recyclate degradation occurs via PP chain scission and PE crosslinking; verification requires dual-weight MFR sweeps and 30-minute OIT testing.
Secondary Organophosphite Hydroperoxide Decomposers
Meaning
Auxiliary antioxidant compounds prevent polymer degradation by reducing unstable hydroperoxides into non-reactive alcohols during high-temperature melt processing. These additives, acting as secondary organophosphite hydroperoxide decomposers, function synergistically with radical scavengers to protect the thermoplastic molecular structure. Their chemical activity stops the auto oxidation cycle from propagating.
This protection prevents resin yellowing and viscosity changes.
Chemical Synergy
Co-stabilizer formulations combine primary and secondary antioxidants to achieve a higher level of protection than single additives can provide. When using secondary organophosphite hydroperoxide decomposers, the primary antioxidants scavenge peroxy radicals while these secondary agents neutralize the resulting hydroperoxides. This cooperative action keeps the polymer stable throughout multiple heat exposures.
It is standard in commercial resin formulations.
Melt Processing
Shear forces and high temperatures during extrusion generate hydroperoxides that threaten the molecular weight of the resin. The inclusion of secondary organophosphite hydroperoxide decomposers prevents these compounds from decomposing into highly reactive alkoxy and hydroxy radicals. This prevention maintains the melt viscosity of the polymer.
Processors can hold tighter tolerances as a result.
Hydrolytic Sensitivity
Additive degradation occurs when moisture is present in the resin during storage or processing. Because many secondary organophosphite hydroperoxide decomposers are sensitive to hydrolysis, proper resin drying is required to prevent additive breakdown. This storage precaution preserves stabilizer efficiency.