Structure‐property relationships in blends of linear low‐ and conventional low‐density polyethylene as blown films

Abstract

Three-layer coextruded blown (either blend or composite) films, made of low-density polyethylene and linear lowdensity polyethylene (1 : 1 ratio) of identical density, were compared. The tensile properties of both systems are nearly as high as those of the linear polyethylene while high strain rate properties including impact strength and tear resistance of the composite film are superior. Some structural insight was obtained by thermal analysis and thermoelastic measurements. Structure property relationships are discussed in light of the unique behavior, structure, and morphology of linear low-density polyethylene. The two polyethylenes are only compatible to a rather limited extent mainly affecting their blend behavior. However, a strong mutual reinforcement effect was observed.gate the mechanical properties of composite blown films consisting of LLDPE and the con-1182 POLYMER

Effect of Metallocene-Catalyzed Polyethylene on the Physicomechanical Properties of Blends with High-Density Polyethylene or Low-Density Polyethylene

“…12 MPa (for mLLDPE1) in a non-linear manner. This reduction in yield strength may be a result of the lower crystallinity of the mLLDPE component [29]. Although this trend is clearly non-linear, the variation in yield strength with composition is similar to that reported elsewhere [15,17] .…”

“…9.5 to less than 6 MPa in a non-linear but uniform manner. This reduction in yield strength may be a result of the lower crystallinities of the mLLDPE components [29,43] . There was no yield strength determined for the 100% mLLDPE3, which has the overall lowest density and crystallinity of all materials used in the blends (see Table 1).…”

“…There was no yield strength determined for the 100% mLLDPE3, which has the overall lowest density and crystallinity of all materials used in the blends (see Table 1). For blends of conventional LLDPE with LDPE, it has been shown that LLDPE increases the yield strength of the blend as a result of the distribution of SCB in the LLDPE matrix [29] .…”

“…Blending conventional LLDPE or mLLDPE with lowdensity polyethylene (LDPE) can result in the production of materials that have significantly better properties than those made entirely from LDPE [26][27][28][29][30] . Such blends are commonly produced in order to obtain film products with high impact strength, optical clarity, good shrinkability or a combination of these attributes.…”

The Effect of Downgauging on the Physicomechanical Properties of Film Blends of Linear Low-density Polyethylene with Low-density Polyethylene

“…Properties such as the impact strength and tear resistance of a typical LDPE film can be enhanced by the addition of LLDPE [4]. Furthermore, blending LLDPE with LDPE can result in significant improvements in other film parameters including toughness, and mechanical and optical properties [16,17].…”