ポリプロピレンーポリエチレク混合物の力学的性質
1967 年 23 巻 4 号 p. 152-157
詳細
1967 年 23 巻 4 号 p. 152-157
Static and dynamic mechanical properties of the blend of polypropylene and low density polyethylene were studied.
Tensile strength and Young's modulus of the blends increases with the increased weight content of polypropylene component, but the elongation at break of the blend which containes 50 wt. % of polypropylene or polyethylene is smaller than the value for each homopolymer and other blends. Also the elongation at break diminishes to a very small value by a heat treatment at a high temperature.
In the viscoelastic absorption curves (dynamic loss vs. temperature curves) for blends only one apparent peak is observed in the vicinity of room temperature for samples whose content of polypropylene are more than 50 wt. % and annealed at low temperature such as 90°C., but two peaks are separated for a sample containing 25 wt. % of polypropylene. The one peak for samples containing large amount of polypropylene separates into two peaks by an annealing at a high temperature such as 120°C. or by a slow cooling from the melt.
These mechanical properties are interpreted in relation with the fine structure of blends and it is concluded that the change of the mechanical properties with a heat treatment must arise from the phase separation by proceeding crystallization.
