Structure and properties of talc‐filled polyethylene and nylon 6 films

Abstract

SynopsisWater vapor transmission rates can be reduced by as much as 50% in polyethylene by using talc as a filler. The oxygen permeability as well as water vapor transmission rates are similarly reduced by talc in nylon 6 films. The films show low elongation at break and reduced breaking strength in the presence of talc. The yield strength and the modulus increase with the amount of talc, whereas the elongation at yield decreases. The mechanical and the barrier properties change with the size of the filler, the smaller size being more favorable. Talc probably acts as a nucleating agent and increases the crystallinity in polyethylene and nylon. Polyethylene unit cells in talc-filled films are oriented with the (110) planes parallel to the (001) planes of talc. Nylon 6 crystals, which are in the Q form in the presence of talc, are oriented with the hydrogen bonded sheets, the (002) planes, parallel to the (001) planes of talc. In both polyethylene and nylon 6, talc is oriented with the c-axis normal to the plane of the film, i.e., with the broad faces of talc flakes in the plane of the film. Lattice matching between the polymer and talc suggests epitaxy to be a contributing factor for the observed orientation of polyethylene and nylon 6 crystals. EXPERIMENTALPolyethylene films were extruded at 216°C through a 3 in diameter tubular film die and blown into 5 in diameter, -1.5 mil thick films. Nylon films were extruded at 266°C through a 4 in diameter tubular die and blown into 2 mil thick, 8 in diameter films. Polyethylene films were produced from Allied resins of three different molecular weights with melt indices

A New Biodegradable Flexible Composite Sheet from Poly(lactic acid)/Poly(ε‐caprolactone) Blends and Micro‐Talc

“…[11] Talc overcomes this disadvantage by better dispersion in the polymer matrix and providing the tortuous path to permeant gas molecules and retard the diffusion of the gas molecules through the matrix. [15,23] The oxygen permeability of PLA/PCL blend and its talc reinforced composites was studied as a function of talc concentration and given in Figure 13. It was studied that addition of talc into PLA/PCL blend results in a significant improvement in oxygen barrier properties of PLA/PCL/talc composites.…”

“…[21] Addition of talc improves the mechanical properties of the composites; however, elongation at break and break strength decreases with the addition of talc [22,23] and tensile modulus increases with the amount of talc. [23] Talc-filled PLA composites was studied and reported to improve flexural, tensile, and impact properties compared to those of neat PLA. [24,25] Talc also increases the heat deflection temperature (HDT) of the PLA.…”

Effect of clay on melt crystallization, crystallization kinetics and spherulitic morphology of poly(trimethylene terephthalate) nanocomposites

“…It has been shown that large amounts of macro-sized and micro-sized fillers are required in order to see a significant change in the desired physical or mechanical properties [12][13][14]. The macro-sized and micro-sized fillers lack an intense interaction within the polymer matrix due to the limited interfacial area.…”

“…The development of composite materials with high strength, high modulus and low density by incorporating fillers such as silica [6][7][8][9][10][11], short glass fibers [12,13], talc, mica [14] and graphite [15] in the polymer matrix has been studied extensively. It has been shown that large amounts of macro-sized and micro-sized fillers are required in order to see a significant change in the desired physical or mechanical properties [12][13][14].…”

Processing/Structure Relationships of Mica-Filled PE-Films with Low Oxygen Permeability

“…Alternating lamellar structures having potentially barrier characteristics may be produced by microlayer coextrusion [2]. Examples of processes favoring flow induced orientation of inorganic platelets are coextrusion blow molding of bottles, or blow film coextrusion for mica filled EVOH resins [18], blown film extrusion for PA-6 or PE films containing talc [19,20], extrusion blow molding of HDPE/talc bottles [21], and injection molding of thin PP/talc or PP/Nylon/talc composites [15]. This last approach has been used to produce polypropylene (PP)/EVOH and polyethylene (PE)/PA-6 ribbons extruded through special dies with converging and diverging sections [4 to 7], LDPE/EVOH blown films [8,9], blow molded high barrier fuel tanks, and containers from polyolefin/polyamide/compatibilizer mixtures with improved barrier characteristics to hydrocarbons, automotive fluids and oxygen [10 to 15].…”