TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Grommes, Dirk
A1  - Schenk, Martin R.
A1  - Bruch, Olaf
A1  - Reith, Dirk
T1  - Initial Crystallization Effects in Coarse-Grained Polyethylene Systems After Uni- and Biaxial Stretching in Blow-Molding Cooling Scenarios
JF  - Polymers
N2  - This study investigates the initial stage of the thermo-mechanical crystallization behavior for uni- and biaxially stretched polyethylene. The models are based on a mesoscale molecular dynamics approach. We take constraints that occur in real-life polymer processing into account, especially with respect to the blowing stage of the extrusion blow-molding process. For this purpose, we deform our systems using a wide range of stretching levels before they are quenched. We discuss the effects of the stretching procedures on the micro-mechanical state of the systems, characterized by entanglement behavior and nematic ordering of chain segments. For the cooling stage, we use two different approaches which allow for free or hindered shrinkage, respectively. During cooling, crystallization kinetics are monitored: We precisely evaluate how the interplay of chain length, temperature, local entanglements and orientation of chain segments influence crystallization behavior. Our models reveal that the main stretching direction dominates microscopic states of the different systems. We are able to show that crystallization mainly depends on the (dis-)entanglement behavior. Nematic ordering plays a secondary role.
KW  - mesoscale coarse-graining
KW  - relaxation
KW  - crystallization
KW  - biaxial stretching
KW  - local chain orientation
KW  - polyethylene
UN  - https://nbn-resolving.org/urn:nbn:de:hbz:1044-opus-65219
SN  - 2073-4360
SS  - 2073-4360
U6  - https://doi.org/10.3390/polym14235144
DO  - https://doi.org/10.3390/polym14235144
PM  - 36501539
VL  - 14
IS  - 23
SP  - 14
S1  - 14
PB  - MDPI
ER  -