New chain extenders that improve the performance of recycled PET

Plastic processing plants are very concerned about and pay attention to the use of recycled polyester and other polycondensation resins, because the mechanical properties of recycled materials are currently lower than new resins, which is not conducive to its recycling or can only be used for low-end products. A new Chain extender has been developed to improve the properties of the shrink polymers such as polyesters, polyamides, polyurethanes and polycarbonates.

Clariant Masterbatch of Winchester, Virginia, United States, in cooperation with Johnson Polymer Co., USA, launched CESA-extend, a series of chain extender masterbatch products. After adding, new bonds are formed between the molecular chains of the polymer precursor resin, thereby improving the parent body. The molecular weight of the resin improves the mechanical properties, rheological properties and processability of the resin, so that the properties of the recycled resin meet the requirements of more applications.

CESA-extend utilizes patented technologies suitable for both companies. The main component is a polyfunctional acrylic oligomer with a small amount. Clariant and Johnson attach great importance to the back-contract polymer market. In the United States, the annual recycling amount of PET resin reaches 318,000 tons. Multi-functional oligomers can increase the melt viscosity, intrinsic viscosity (IV), and recyclate strength and solid content of recycled shrink polymers. The polymerization can achieve comparable strength.

The low moisture sensitivity and high hydrolytic stability of the chain extender modified regrind are the advantages that the compounding plant welcomes, and the compatibility of recycled materials with other materials such as PC/ABS, PET/PA, etc. has also been improved. The recycled resin melt has high strength and is suitable for sheet extrusion, spinning and extrusion blow molding processing requirements. The chain extender will cause long chain branching of the parent resin molecules, but will not increase the tendency of the gel to form in the final product.