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The linear low density polyethylene (LLDPE)/zeolite composite using novel inorganic filler, zeolite, is prepared by a conventional compounding procedure using a twin-screw extruder. The observed scanning electron microscopic (SEM) morphology shows a good dispersion and adhesion of zeolite in the LLDPE matrix. The mechanical properties in terms of the Young's modulus, the yield stress, the impact strength, and the elongation at break were enhanced with a successive increment of zeolite content up to 40 wt%. The X-ray diffraction measurement is of supportive for the improved mechanical properties and the complex melt viscosity is as well. Upon applying a certain level of strain on the composites, the dewetting, the air hole formation and its growth are characterized. The dewetting originates around the filler particles at low strain and induces elliptical micropores upon further stretching. The microporosity such as the aspect ratio, the number and the total area of the air holes is also characterized. Thus, the composites loaded 40 % zeolite and 300 % elongation may be applicable for breathable microporous films with improved modulus, impact and yield stress, elongation at break, microporosity and air hole properties.

We have studied the effects that inorganic zeolite powder have on structurally different copolymer [poly(propylene-co-ethylene)] and terpolymer [poly(propylene-co-ethylene-co-1-butene)] systems and the possibility of preparing suitable porous composite films. The impact strength and yield stress of the composites did not improve upon any further loading of zeolite, but the modulus increased gradually with respect to the filler loading. The experimental modulus of each of the two systems was compared with theoretical models. We performed a morphological study of the filler mixing efficiency and image analysis. The number-, weight-, and z-average air hole diameters were compared with respect to the draw ratio as well as the zeolite loading. The experimental results suggest that these two matrices can provide a new choice for preparing future multiphase polymeric porous films by stretching them unidirectionally. In particular, we suggest that a 40 wt% zeolite loading at a draw ratio of 4 is useful for porous film applications.

This work was designed to study the effects of inorganic calcite powder on structurally different copolymer [poly(propylene-co-ethylene)] and terpolymer [poly (propylene-co-ethylene-co-1-butene)] matrices and the possibility of making a suitable porous composite film. The yield stress of the composites did not improve, but the modulus increased gradually with the filler loading. The theoretical and experimental modulus and yield stress of the composites provided evidence of filler and polymer adhesion behavior. The impact strength showed little enhancement up to a 20 wt % loading for the poly(propylene-co-ethylene-co-1-butene) system. The number-average, weight-average, and z-average air-hole diameters were compared with respect to the draw ratio as well as the calcite loading. The morphology of a micromechanically deformed composite, studied with an image analyzer, revealed that the aspect ratio and area of the air holes increased linearly as a function of the draw ratio, but the change in the aspect ratio upon filler loading was not remarkable. A suitable loading of a filler up to 30 wt % was good for controlling the porosity in the composite films.