Nanocomposites of polyolefine matrix Part II. LDPE/PP BLENDS/CLAY
Jolanta Janik, Grzegorz Krala, Wacław Królikowski
Quarterly No. 3, 2009 pages 276-281
DOI:
keywords: nanocomposites, blends, polyolefine, polypropylene, polyethylene, clay, montmorillonite, compatibilizer
abstract Introduced work refers research over nanocomposites with the polyolefine matrix polyethylene/polypropylene with of powder nanofiller, clays-montmorillonites. Poliolefine (the main of polyethylene LDPE, HDPE and polypropylene PP) are dominating in postconsumer wastes. The aspect of this research is recycling of PP and PE wastes without segregation necessity. Polymer blends produced from those unseparated polymer wastes seem to be one of the ways to receive utilisable products. Three different mixtures of LDPE/PP blends are prepared (% wt.): 85%LDPE/15%PP; 50%LDPE/50%PP and 15%LDPE/85%PP. Using this blends the nanocomposites by adding to them the concentrates - “master batch” was produced. To the blends the concentrates of nanofiller (Organobentonit, Nanofil 5)/compatybilizer (Polybond X5104 - PB) was added. The content of nanofiller and compatybilizer in nanocomposites was properly 5 and 10% weights. For the comparison one prepared also LDPE/PP blends with the participation alone of compatybilizer (10wt. %) and LDPE/PP blends with the participation alone nanofiller (5wt. %). Blends of LDPE/PP and nanocomposites were compounded by melt mixing using the corotating, twin-screw Mapre’s extruder having an L = 32D, by screw speed 300 rpm. Normalized samples for evaluation of the mechanical properties by using BOY’s type 15S screw injection moulding machine were moulded. Present paper shows results of mechanical properties - tensile strength (m) and flexural strength (fm), elasticity modulus (Et) and flexural modulus (Ef), elongation at break (B), thermal properties (DSC, DMTA) and the morphological structure of blends and of nanocomposites (TEM, SEM). The SEM of rupture surfaces of the samples stretched at the liquid nitrogen (brittle fracture) were taken. Polyolefine blends (LDPE/PP) are thermodynamically immiscible, DSC and DMTA of them demonstrated measurement of two glass transition temperatures (Tg) respectively for: LDPE and PP independently of the composition. One ascertained that one could not discern compatybilizing of the activity-introduced nanofilers: Organobentonit as and Nanofil 5. The introduction to blend 10 wt. % compatybilizer apparently improves all measured mechanical parameters, aside from the participation PP, does not influence instead on the change of glass temperatures and melt of base polymers in the blend. The morphological analysis (SEM) showed that mixtures of LDPE/PP/PBX5104 and LDPE/PP/nanofiller are immiscible (obtained structures are heterogeneous). The addition to blends of the concentrate nanofiller/compatybilizer influences significantly the increasing of mechanical parameters. TEM image did not show full exfoliation of plate’s clay in the matrix LDPE/PP.