Water-retaining liquid mulching film and preparation method and application thereof

Abstract

The invention discloses a preparation method and application of a liquid mulching film capable of forming a layer of hydrophobic film on the surface of an object after spraying. The liquid mulching film is prepared from, by weight, 1-35 parts of polymer emulsion, 0.1-2 parts of film-forming adjuvant and other functional additives, wherein the glass transition temperature of the contained polymer is -50 DEG C to + 50 DEG C, and the particle size distribution of the emulsion is 50 nanometers to 600 nanometers. After being sprayed, the liquid mulching film provided by the invention can quickly form a film which is as hydrophobic as an existing mulching film (with a contact angle of more than 90 degrees), impermeable and capable of blocking moisture volatilization of an object on the surface of the object (such as soil, sand and pavement), plays a role in water retention, moisture preservation and heat preservation, and is applied to agricultural production and the like.

Description

technical field [0001] The invention relates to an emulsion, in particular to a liquid composition mainly composed of a hydrophobic polymer or a low molecular weight oligomer emulsion, which can form a dense hydrophobic film after being sprayed on the surface of soil and the like, and block the volatilization of water to play a role The function of water retention and heat preservation. The liquid mulch film does not form large film fragments after use, which avoids the pollution problem of common agricultural mulch films. Background technique [0002] Agricultural mulch is a layer of film covering the soil, which can block the volatilization of water in the soil and play a role in water and moisture conservation. This is especially important for agricultural production in arid areas and has become an indispensable means of production for modern agriculture. However, a large number of widely used mulches are made of non-degradable vinyl polymer plastics, which are difficult...

AI Technical Summary

Problems solved by technology

Liquid film raw materials are composed of polyvinyl alcohol, foaming agent, film forming agent, vinyl acetate, lignin, sodium benzoate, bone glue, sodium cellulose, etc. The main component is hydrophilic polyvinyl alcohol, and there are also some with poor water retention performance. shortcoming

[0009] Documents CN102477304A and CN101343383A all refer to adopting natural polymer materials: starch, chitosan, cellulose (sodium carboxymethyl cellulose, etc.) as degradable materials to prepare liquid film, but these natural polymers contain a large number of polar groups (Hydroxyl, carboxyl) have strong hydrophilicity and even water solubility, so the formed film cannot exert the characteristics of water resistance and moisture retention; at the same time, these natural polymer materials are expensive and poor in film formation, and graft modification, Adding film-forming adjuvants and other methods increases production costs

[0010] Analyzing the composition of existing liquid mulch formulas, it can be seen that their main film-forming materials are hydrophilic materials such as natural sugar-based polymers and polyvinyl alcohol, and the formed films are hydrophilic. Therefore, the water molecules in the soil reach This kind of hydrophilic film will be absorbed by it, and then volatilized on the upper layer of the film, so it can't play a good role in water retention

Images