Rheological behavior and mechanical properties of high‐density polyethylene blends with different molecular weights

Abstract

ABSTRACT:The dynamic rheological and mechanical properties of the binary blends of two conventional highdensity polyethylenes [HDPEs; low molecular weight (LMW) and high molecular weight (HMW)] with distinct different weight-average molecular weights were studied. The rheological results show that the rheological behavior of the blends departed from classical linear viscoelastic theory because of the polydispersity of the HDPEs that we used. Plots of the logarithm of the zero shear viscosity fitted by the Cross model versus the blend composition, Cole-Cole plots, Han curves, and master curves of the storage and loss moduli indicated the LMW/HMW blends of different compositions were miscible in the melt state. The tensile yield strength of the blends generally followed the linear additivity rule, whereas the elongation at break and impact strength were lower than those predicted by linear additivity; this suggested the incompatibility of the blends in solid state.

Unexpected molecular weight dependence of shish kebab in water‐assisted injection molded HDPE

“…Thus, the HMW HDPE is more viscous than LMW HDPE. This can be also documented by Ref . in which the HDPEs were the same as the ones in this study.…”

Development of novel melt-compounded starch-grafted polypropylene/polypropylene-grafted maleic anhydride/organoclay ternary hybrids

“…The TTS principle states that, when studying the viscoelastic behaviour of a material (for instance complex viscosity or complex elasticity modulus), a change of temperature is completely equivalent to a shift of the logarithmic time scale (so-called timeshift); such a material is termed 'thermo-rheologically simple' [30]. It is usually believed that TTS principle fails for polymer blends in phase separated state, and works in miscible state [28,29]. If an excellent superposition is obtained when plotting the rheological master curves at a reference temperature, then the polymer blend is fully miscible; if not, it is assumed to be immiscible or partially miscible only.…”

“…One of the most frequently used methods to judge whether the blend is fully miscible (i.e. behaves as a single-phase system with no phase separation) or in phase separated state is the timetemperature superposition (TTS) principle [28,29]. The TTS principle states that, when studying the viscoelastic behaviour of a material (for instance complex viscosity or complex elasticity modulus), a change of temperature is completely equivalent to a shift of the logarithmic time scale (so-called timeshift); such a material is termed 'thermo-rheologically simple' [30].…”

Rheological behavior of ultrahigh molecular weight polyethylene/low‐density polyethylene blending gels with high solid content

“…However, this requirement can be satisfied by the fibers prepared from the blend of UPE and normal molecular weight PEs. Some attempts have been carried out in the preparation of blending fiber of UPE with other components , such as high density polyethylene (HDPE), low density polyethylene (LDPE), and linear low density polyethylene (LLDPE), using melt spinning method , but phase separation of some extent was occurred in the melt state of those blends, which was a disadvantage for melt spinning process and the strength of the resultant blending fibers.…”