Preparation method of 1,3-2,4-di(p-methyl)benzylidene-1-allyl sorbitol

Abstract

The invention relates to a preparation method of 1,3-2,4-bis(p-methyl) benzal-1-allyl sorbitol. The method comprises the following steps: performing a stirring reaction on glucose and allyl bromide which are taken as raw materials as well as Sn powder and SnCl2 which are taken as catalysts in an acid solution in which water and ethyl alcohol are taken as solvents for 24 to 48 hours at a room temperature; performing neutralization and suction filtration after the reaction so as to remove the solvents to obtain an intermediate product 1-allyl sorbitol; reacting within 62 DEG C to 67 DEG C in a slow heating manner by taking the 1-allyl sorbitol and p-methyl formaldehyde as the raw materials, p-methyl benzenesulfonic acid as the catalyst, cyclohexane as the solvent and methyl alcohol as an accelerant; cooling to the room temperature when water is no longer generated in the reaction; performing the neutralization and the suction filtration; sequentially washing and refining the mixture with boiling water and an organic solvent so as to obtain the 1,3-2,4-bis(p-methyl) benzal-1-allyl sorbitol.

Description

technical field [0001] The invention relates to a preparation method of acetal compounds, in particular to a preparation method of 1,3-2,4-di(p-methyl)benzylidene-1-allyl sorbitol. Background technique [0002] Polypropylene (PP) has become the fastest growing general-purpose plastic in the world and is widely used due to its light weight, low price, non-toxic, tasteless, corrosion resistance, high temperature resistance, high mechanical strength, and good chemical stability. In chemical industry, construction, light industry and other fields. However, PP is a partially crystalline resin. Under normal processing conditions, the crystallinity of PP is low. The diameter of spherulites is larger than the wavelength of visible light, and the incident light is scattered, thereby reducing the light transmittance. Therefore, the gloss and transparency of the product are poor, and the appearance The lack of aesthetic feeling limits its application in packaging, medical equipment, h...

AI Technical Summary

Problems solved by technology

The first-generation nucleating agent is unsubstituted dibenzylidene sorbitol, which can improve the surface gloss and physical and mechanical properties of the product, but its anti-reflection effect on PP is not ideal, and it is unstable at high temperatures. During the processing of PP, it is easy to decompose and release the parent aldehyde, which has a certain odor

The second-generation product introduces substituent groups such as alkyl, alkoxy, and halogen on the basis of the first generation. The second-generation nucleating agent has good nucleation effect and better transparency, but there are bubbles during processing and use. Problems such as large number and strong smell

However, in the process of preparing intermediate products, the allylation reaction of raw glucose needs to be carried out under the protection of nitrogen gas at the reflux temperature of the solvent, and after the reaction, it needs to be repeatedly decolorized and filtered with activated carbon. The operation steps are cumbersome and the reaction process is not easy to control. , and the final product has a low melting point

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