Chain extenders are suitable to increase the molecular weight of semi crystalline polymers; the addition of XIBOND™ will result in improved melt strength
Polycondensation polymers, like polyesters and polyamides tend to degrade during processing, which results in the loss of molecular weight. This leads to loss of important material properties, especially melt strength. Chain extenders can improve the melt strength by connecting the chains via a chemical reaction with functional groups such as the OH, C00H and NH2 groups of the polymer. This results in a reduced melt flow index (MFI) and thus increased viscosity.
The addition of XIBOND™ chain extenders to thermoplastic polyesters and polyamides will lead to branched structures, since it has multiple groups which can react with the polymer matrix. The XIBOND™ portfolio offers a wide range of maleic anhydride functional polymers which are especially suitable for polyamides. The XIBOND™ range also consist of Glycidyl methacrylate (GMA) functional polymers, the epoxy functionality can react with thermoplastic polyesters. Melt viscosity is increased as a result of the reaction of the functional groups with either carboxylic or amine end groups. In most cases the use of the additive leads to an improvement in the mechanical properties of the polymer, in addition to the observed stabilization in melt flow.
Benefits Chain Extenders
- Improved melt strength
- Optimized processability
- Controllable thickness