Rotomolded polyolefin composition and preparation method thereof

Abstract

The invention relates to a polyolefin composition, in particular to a rotomolded polyolefin composition and a preparation method thereof. The rotomolded polyolefin composition comprises polyethylene,hyperbranched polyethylene, a nucleating agent, an acid absorbent, an ultraviolet absorbent, and an antioxidant, wherein the hyperbranched polyethylene, the nucleating agent, the antioxidant and the acid absorbent are pretreated; to be specific, the hyperbranched polyethylene, the nucleating agent, the antioxidant and the acid absorbent are mixed, n-hexane is added, a solvent is removed after heating and reflowing, and drying is performed. The rotomolded polyolefin composition and the preparation method thereof have the advantages that mechanical properties of rotomolding materials can be significantly improved, melt viscosity (low zero-cut viscosity) is reduced, the produced rotomolded product has smooth inner and outer surfaces and good plasticity, the section of the product has no evident bubbles, heating time is short, demolding is facilitated, and the product has long-term ultraviolet ageing resistance. The invention also provides the preparation method of the rotomolded polyolefin composition.

Description

technical field [0001] The invention relates to a polyolefin composition, in particular to a rotationally molded polyolefin composition and a preparation method thereof. Background technique [0002] In rotational molding, the rotational speed of the mold is relatively low, and the shearing effect received by the raw material is almost zero. At such a low rotational speed, the plastic powder is always kept at the bottom of the cavity by the action of gravity. With the rotation of the hot mold, the plastic powder flows continuously. When the mold is heated to a certain degree, the plastic powder continuously melts and adheres uniformly. onto the inner surface of the mold cavity to form the desired shape. [0003] Due to the particularity of the rotational molding process, the raw materials for rotational molding are required to have a higher MFR than raw materials such as blow molding and extrusion. If the body viscosity is too low, there will be a large number of bubbles i...

AI Technical Summary

Problems solved by technology

[0003] Due to the particularity of the rotational molding process, the raw materials for rotational molding are required to have a higher MFR than raw materials such as blow molding and extrusion. If the body viscosity is too low, there will be a lot of air bubbles in the product, which will increase the rotational molding time and the amount of additives

The performance of the product can be improved by modification, but because there is almost no shear in the whole process of rotomolding, the heating and cooling rate of the raw material is slow, any melt viscosity different from the raw material matrix, different crystallization temperature, inorganic fillers, etc. will have a negative impact on the matrix resin. , so the key to improving the performance of rotomolded products by modification is the selection of foreign components and how to solve the compatibility between matrix resin and foreign components

[0004] Patent CN201510234531 provides a highly filled polyethylene composition and its preparation method and application. The amount of hyperbranched polymer is 0.5-2 parts. Through the combination of various components, the purpose is to increase the proportion of filler in the resin to more than 60%. Suitable for rotational molding

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