A kind of preparation method of high-grafting-rate polyolefin graft and application of the high-grafting-rate polyolefin graft

Abstract

A preparing method of a polyolefin graft having a high grafting ratio is disclosed. The method includes (1) replacing air in a reaction kettle with nitrogen, and then heating the reaction kettle to 80-180 DEG C, (2) adding a polyolefin under nitrogen protection to the reaction kettle, adding a reaction monomer, an initiator and a crosslinking inhibiting agent after the polyolefin is melted, and reacting the mixture under stirring, and (3) vacuumizing the reaction kettle, then proceeding with the reaction, and subjecting a material prepared by the reaction to high-pressure extrusion, strip drawing and pelletizing to obtain the polyolefin graft. The polyolefin graft prepared by the method has advantages of the high grafting ratio, a low crosslinking degree, weak smell, light color, a low monomer residual amount, high adhesive force, and the like, wherein the grafting ratio of maleic anhydride can reach 4.89%, the monomer residual amount is 0.05% or below, and the adhesive strength can reach 30 N / 15mm.

Description

technical field [0001] The invention relates to a preparation method of a polyolefin graft, in particular to a preparation method of a high grafting rate polyolefin graft and the application of the high grafting rate polyolefin graft. Background technique [0002] Multi-layer composite film is a film that combines different materials together through multi-layer co-extrusion technology, has the advantages of different materials, and has some special functions; multi-layer composite film is generally composed of a base layer, an adhesive layer and a functional layer. Composition, wherein the function of the bonding layer is to improve the compatibility between the base layer and the functional layer, and the bonding layer is mainly a polyolefin graft. [0003] In the application of engineering plastics, due to the polarity difference between different polymers and between polymers and fillers, it is necessary to add a compatibilizer during the modification or alloying process...

AI Technical Summary

Problems solved by technology

[0004] At present, the preparation of polyolefin grafts is mainly through melt extrusion. During the preparation of polyolefin grafts by melt extrusion, the molecular chains are easily broken, and the macromolecules are easily cross-linked. The cross-linking reaction makes the product gel High content, it is also easy to cause crystal points in the application of multi-layer composite films, resulting in film rupture

In addition, the polyolefin graft prepared by the melt extrusion method has dark color, heavy taste, and high residual monomer content, making it impossible to be used in food packaging films

In the application of compatibilizer and toughening agent, the polyolefin graft prepared by melt extrusion reaction method has a low graft rate, and often needs to add a large amount of graft to achieve the toughening effect or compatibilization purpose. In addition, The crosslinking reaction of the melt grafting method will easily cause the viscosity of the system to increase, the rheological properties will deteriorate, and the processability will be poor, which is not conducive to the application of toughening modification and compatibility modification

In addition, the preparation of polyolefin grafts by melt extrusion requires high equipment requirements, such as corrosion resistance of the extruder, large aspect ratio, high vacuum, complex design and high price.

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