Polymer Compatibilizer for Recycling

- January 01, 2016 -

When two or more polymers are blended together, either as recycle streams or in other blends and alloys, often times they are not compatible with each other. Thus, the resulting blend has insufficient properties for most end uses. Functional additives can improve this compatibility.

The general principle of compatibilization is to reduce interfacial energy between two polymers in order to increase adhesion. Generally, adding a polymer compatibilizer also results in finer dispersion, as well as more regular and stable morphologies.

Adding compatibilizers (typically at 5 - 7 wt%) generally increases mechanical performance and surface properties.

Dow Recommended Compatibilizing Systems

 PP/PA  5-7% Fusabond® 
 LDPE, LLDPE  5-7% Fusabond®, 5-7% Surlyn®
 HDPE  5-7% Fusabond®, 5-7% Surlyn®
 PVC  5-7% Fusabond®
PE/PA   Fusabond® M603, Fusabond® E226
PE/EVOH or PA/EVOH/PE  Fusabond® M603, Bynel® 41E710
Surlyn® EVOH or PA   Fusabond® E226, Surlyn® 1650 for sodium Surlyn® streams
PP/PA or PP/EVOH/PP  Fusabond® P353
Polyesters/PE  Elvaloy® PTW and Elvaloy® AC 3427

Fusabond® Polymer Compatibilizing Resin for Polyamides (Nylon 6 and Nylon 66)

Using Fusabond® polymer compatibilizer can help reduce waste when recycling polyamides that may be contaminated with other resins such as PP, PE or polyesters. It also can help create flexible alloys made with nylon (PA) and polyolefins, or improve the dimensional stability of PA-PP alloys, for example using Fusabond® P353 or P613 modifier resin.

Elvaloy® PTW & Elvaloy® AC Polymer Compatibilizing Resins for PET and PBT

When recycling polyesters that may include mixed resins or contaminants, using Elvaloy® polymer compatibilizer can help cut waste and enhance properties. Compatibilizing polyester alloys often makes them easier to process (extrude and/or thermoform). Polyesters can also be compatibilized with polyethylene, polypropylene or polycarbonate resins, enabling up to 40% non-polyester content. A typical application for this technology is seedling trays.

Polyolefin (PE and PP) Compatibilizing Resins

Using a Dow polymer compatibilizer can help build more cost-effective mechanical and optical properties using scrap/regrind/reuse material from multilayer films, bottles or sheet products. For rigid applications, adding Fusabond® as a compatibilizer improves mechanical properties to enable processing and direct recycling into the structure or into new applications (for example, tubing, blow-molded bottles, sheets).

For film applications, adding Fusabond® as a compatibilizer improves mechanical properties and reduces haze and defects, especially in EVOH- and PA-containing structures. Compatibilized and pelletized film regrind can be fed back into other film systems where some haze can be tolerated.