High-toughness polypropylene and preparation method thereof

Abstract

The invention belongs to the technical field of polymer processing, and particularly relates to high-toughness polypropylene and a preparation method thereof. The polypropylene is only composed of pure isotactic polypropylene, the axial tensile strength of the polypropylene is 50-60MPa, and the elongation at break of the polypropylene is 700-800%. According to the high-toughness polypropylene andthe preparation method thereof, the concept of grain refinement in metal materials is applied to isotactic polypropylene material processing for the first time, and meanwhile the influence of grain orientation is considered. The preparation method of the high-toughness polypropylene comprises the steps that polypropylene melt is stretched at a high speed at a certain temperature, molecular chain orientation is promoted, then high-speed cooling is conducted immediately, the melt is solidified, and a polypropylene product with a high-density and strong-orientation microcrystalline structure is prepared. Meanwhile, the obtained polypropylene has the large elongation at break and shows ultrahigh toughness under the condition that the high tensile strength is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of polymer processing, and in particular relates to a high-toughness polypropylene and a preparation method thereof. Background technique [0002] Polypropylene material has many excellent physical properties such as light weight, good transparency, flex resistance and chemical stability, and is widely used in many fields such as packaging, automobiles and national defense. At present, industrial polypropylene is mainly isotactic polypropylene, which has high molecular regularity and strong crystallization ability. However, the glass transition temperature of isotactic polypropylene is close to -20°C to -30°C, which is slightly lower than normal temperature, that is, the molecular chain movement ability is weak, and it is easy to cause poor toughness and impact resistance of its products such as injection molded parts, pipes, and films. The strength is low, which greatly limits its application range. [00...

AI Technical Summary

Problems solved by technology

However, on the one hand, the addition of functional additives will affect the intrinsic optical, density and other physical properties of polypropylene materials. On the other hand, the change of crystal form increases the elongation at break, and is often accompanied by a decrease in modulus and tensile strength.

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