Evolution of iPP/HDPE Morphology under Different Mold Temperatures via Multiflow Vibration Injection Molding: Thermal Field Simulation and Oriented Structures

Abstract

To date, many advanced polymer processing technologies have been developed to tune the morphology of semicrystalline polymers, such as multiflow vibration injection molding (MFVIM). By adjusting the processing fields, i.e., shear and thermal fields, the material can be imparted with great mechanical properties, good electrical/thermal conductivity, or biomimic structure, by manipulating chain's orientation, crystal's arrangement, or hierarchical structure distribution. Despite the era of intelligent manufacturing approaching, there is rarely any report on the computer simulation of these advanced processing technologies. In this work, the processing fields of the MFVIM isotactic polypropylene/high-density polyethylene (iPP/ HDPE) part are successfully simulated using Moldflow by designing a special model. Different thermal gradients can be realized in the plate part by setting different mold temperatures. The experimental results correlate well with the simulation results, and both of them illustrate that the mold temperature plays an important role in the morphology of dispersed PE phase resulting in different physical properties.

Effect of morphology development on the low‐temperature tensile properties ofPP/POEblends

“…It is noteworthy that the elongation at break of PP/POE/ r PP decreased dramatically upon increasing the mold temperature, indicating that the modification effect of r PP was closely related to the mold temperature. Generally, a higher mold temperature means a lower viscosity and longer relaxation time, which promote the motion of molecular chains and the formation of PP crystals 32 . Since elongation at break is closely related to the phase morphology development, as revealed by the above study, we examined the phase morphology of samples prepared using different mold temperatures.…”

“…Generally, a higher mold temperature means a lower viscosity and longer relaxation time, which promote the motion of molecular chains and the formation of PP crystals. 32 Since elongation at break is closely related to the phase morphology development, as revealed by the above study, we examined the phase morphology of samples prepared using different mold temperatures. The SEM images are shown in Figure 8.…”

Novel Strategy to Improve the Performance of Poly(l-lactide): The Synergistic Effect of Disentanglement and Strong Shear Field

“…Software Moldflow2018 was used to simulate the VIM process. Based on the conventional model, two diameter-tunable hot runners and an overflow groove were modeled . The diameter of hot runners was adjusted to make sure that the melt does not enter the groove before the packing stage.…”

Poly(ether ester) and related block copolymers via organocatalytic ring‐opening polymerization

“…9,10 More importantly, PPDO has proven to be pliable than PLA, PGA, and high-density polyethylene (HDPE) for an ultimate elongation ranging from 500% to 600% with a tensile strength closed to 7000 psi. [11][12][13] Furthermore, in pursuit of the preparation of medical grade PPDO and related copolyesters, great efforts have been done on the utilization of organic catalysts in replacement of the traditional metal-based catalysts via ringopening of (co)polymerization, because organocatalysts show potential advantages of simplicity, versatility and high activity. [14][15][16][17][18][19][20][21][22][23][24][25][26][27] Though great advancements on the synthesis, properties and applications of PPDO have been achieved, many questions remain for this material, such as its thermal instability and poor solubility in common organic solvents, limiting its further applications and processing.…”

“…For example, PPDO can completely degrade in human body within a period of 180 days that is similar to polyglycolide (PGA) but quite faster than polylactide (PLA), thus render PPDO satisfactory for many biomedical applications 9,10 . More importantly, PPDO has proven to be pliable than PLA, PGA, and high‐density polyethylene (HDPE) for an ultimate elongation ranging from 500% to 600% with a tensile strength closed to 7000 psi 11–13 . Furthermore, in pursuit of the preparation of medical grade PPDO and related copolyesters, great efforts have been done on the utilization of organic catalysts in replacement of the traditional metal‐based catalysts via ring‐opening of (co)polymerization, because organocatalysts show potential advantages of simplicity, versatility and high activity 14–27 …”