Melt miscibility of HDPE/UHMWPE, LDPE/UHMWPE, and LLDPE/UHMWPE blends detected by dynamic rheometer

Abstract

The dynamic rheological behavior of high density polyethylene (HDPE)/ultrahigh molecular weight polyethylene (UHMWPE) blends, low density polyethylene (LDPE)/UHMWPE blends and linear low density polyethylene (LLDPE)/ UHMWPE blends was measured in parallel plate rheometer at 200°C. The analysis of log additivity rule, Cole-Cole plots and Han curves of the three series blends indicated that the LDPE/UHMWPE blends were miscible in the melt, while the HDPE/UHMWPE blends and LLDPE/UHMWPE blends showed phase separation. The DSC results of LLDPE/UHMWPE blends and HDPE/UHMWPE blends were consistent with the rheological properties, while for the thermal properties of LDPE/UHMWPE blends, results revealed three endothermic peaks, which indicated a liquid solid phase separation in LDPE/UHMWPE blends.

Rheological and mechanical properties of blends of LDPE with high contents of UHMWPE wastes

“…However, the rheological behavior obtained for the 50/50 wt % blends with two and three extruder passes reveals a better homogeneity of R‐UHMWPE in LDPE in the melts, but not an intimate mixing at a molecular level such as occurs in solution blending. The latter is not consistent with the results reported by Chen et al ., who found miscibility at the melt state at 200 °C for the blend with 40 wt % of UHMWPE nascent powder in an LDPE matrix with an MFI value similar to that used in this work. Their blends were prepared in a mixer at 190 °C for 10 min.…”

“…Moreover, with successive extrusion cycles, there is a reduction in the occurrence of gels (undispersed particles or more fine particles); that is, a better blend dispersion is attained. Therefore, a liquid–solid phase separation exists that is due to the different crystallization rates of both components of the blend …”

“…These blends exhibited a rise in complex viscosities as well as in the storage and loss modulus with the increase in the proportion of UHMWPE nascent powder. This behavior was attributed to the addition of a polymer with very high molecular weight to the continuous phase, which restricts the mobility of the matrix …”

Evaluation of Aging Resistance in UHMWPE/LLDPE Blend‐Based Carbon Nanotubes Nanocomposites

“…Regarding DSC results, the neat LLDPE shows a relatively broad peak due to its branching. The broad peak response is composed of a low temperature shoulder and a high temperature peak . It was observed that UHMWPE/LLDPE blends with different contents of LLDPE (10, 20, and 30 wt%) are miscible blends, presenting only one melting temperature ( T m ) and crystallization temperature ( T c ) for each mixture.…”

Thermal, Mechanical and Rheological Behaviors of Nanocomposites Based on UHMWPE/Paraffin Oil/Carbon Nanofiller Obtained by Using Different Dispersion Techniques

“…Additionally, other literature papers have studied the effect of filler materials on rheological behavior by using dynamic rheometry [16][17][18][19][20] because of the high complex viscosity of UHMWPE due to its high molecular weight. In particular, Chen Ma et al (2014) studied all the above mentioned thermal and rheological features of UHMWPE based nanocomposites and CNF modified with ionic liquid by sonication, mixed by stirring and then added with antioxidant using a twin-screw blender.…”