How to Regulate the Proportion of PE Wax with Different Degrees of Polymerization to Balance Viscosity and Crystallization Rate?

The molecular structure regulation of PE wax involves the precise control of carbon chain length and branching degree. The antagonistic relationship between melt viscosity and crystallization rate originates from the dynamic balance between molecular mobility and nucleation rate. Low-polymerization components improve melt fluidity by reducing entanglement density, but too short molecular chains weaken the crystallization driving energy, resulting in a widening of grain size distribution. High-polymerization segments provide cross-linking nodes to promote heterogeneous nucleation, but the flow resistance is aggravated by the prolonged relaxation time of the chain segments.

In the synthesis process, the gradient distribution design of the catalyst active center can realize the in-situ compounding of molecules with different chain lengths. This asymmetric structure enables oligomers to act as melt plasticizers while retaining an appropriate amount of long-chain molecules as crystallization templates. Crystallization kinetics regulation needs to match the melt cooling rate and optimize the nucleus density by segment orientation within the supercooling window.

The improvement of PE wax rheological properties relies on the synergistic response of components with different degrees of polymerization in the shear field. Short-chain molecules reduce zero shear viscosity to improve processability, while long-chain molecules maintain tensile viscosity to inhibit melt fracture. This dual-mode distribution structure can shorten the filling time in injection molding while ensuring the integrity of the crystalline structure during demolding. The annealing process in the post-processing stage can further balance the volume ratio of the crystalline region and the amorphous region through molecular chain rearrangement, achieving the unity of the mechanical properties and surface finish of the product.

The peak position shift and half-peak width adjustment of the PE wax molecular weight distribution curve need to be combined with the thermal history conditions of the terminal application scenario. Under high temperature conditions, it is necessary to inhibit the migration of oligomers and improve thermal stability by introducing moderate branching structures. In low temperature environments, the short chain ratio needs to be optimized to prevent excessive crystallinity from increasing brittleness. This dynamic balance mechanism enables PE wax to maintain performance stability under complex processing conditions.