CN102911385A - Preparation method of high-strength degradable composite film - Google Patents

Abstract

The invention discloses a preparation method of a high-strength degradable composite film, which comprises the following steps of a, adding polyvinyl alcohol and a reinforcing agent to 20-50 g/L of soybean protein solution, dissolving and stirring uniformly, then adding ethyl acetate and stirring uniformly; b, adjusting pH to be 6-7, heating to 75-90 DEG C and adding 12-20 g/L glycerol to react for 1-2 h; and c, vacuumizing a reaction vessel, coating a reaction product, and drying to obtain the film, wherein the mass ratio of the polyvinyl alcohol to soybean protein is 1:(1-1.5); the reinforcing agent is a mixture of carboxymethyl cellulose and artemisia glue with the mass ratio of 1:(1-1.5); and the addition amount of the reinforcing agent is 0.5-2 g/L. The prepared composite film according to the method is degradable, the tensile strength, the elongation at break and other mechanical properties are improved greatly, and the strength requirements of film packages are met.

Description

A kind of preparation method of high-strength degradable laminated film

Technical field

The invention belongs to field of food industry, relate in particular to degradable food product packing film.

Background technology

The plastics film of oil by product, impels degradable macromolecule membrane progress of research environment owing to hard degradation.But the physical strength of present most degradable films is inadequate, is difficult to satisfy the requirement of packing.

Summary of the invention

Goal of the invention: for the problem and shortage of above-mentioned existing existence, the purpose of this invention is to provide a kind of preparation method of high-strength degradable laminated film.

Technical scheme: for achieving the above object, the present invention by the following technical solutions: a kind of preparation method of high-strength degradable laminated film may further comprise the steps:

A, in the soy bean proteinous soln of 20～50g/L, add polyvinyl alcohol and toughener, dissolve and stir, then add vinyl acetic monomer, stir; The mass ratio of wherein said polyvinyl alcohol and soybean protein is 1:1～1.5; Described toughener is the carboxymethyl cellulose of 1:1～1.5 and the mixture of husky punt-pole glue by mass ratio, and addition is 0.5～2g/L;

B, then to regulate pH be 6～7, is heated to 75～90 ℃ and add the glycerine of 12～20g/L, reaction 1～2h;

C, reaction vessel vacuumized after, reaction product is filmed, and drying obtains film.

Beneficial effect: compared with prior art, the present invention has the following advantages: the laminated film of the present invention preparation has degradability, and the mechanical propertys such as tensile strength, elongation at break are largely increased, and satisfies the requirement of film packaging intensity.

Embodiment

Below in conjunction with specific embodiment, further illustrate the present invention, should understand these embodiment only is used for explanation the present invention and is not used in and limits the scope of the invention, after having read the present invention, those skilled in the art all fall within the application's claims limited range to the modification of the various equivalent form of values of the present invention.

In the soy bean proteinous soln of 30g/L, add successively the polyvinyl alcohol of 30g/L, the carboxymethyl cellulose of 0.8g/L and the husky punt-pole glue of 1g/L, dissolving also stirs, and then at the vinyl acetic monomer that adds 100ml/L, then regulating pH is 7.0, and heat to after 85 ℃ the glycerine that adds 15g/L, reaction 2h obtains the thickness product, and reaction vessel is vacuumized the bubble of getting rid of in the product, then films, and dry, finish.

The degradable films that aforesaid method obtains is translucent, and transmittance is 15%, and it is done measuring mechanical property: tensile strength is 4.2～5.1MPa, and elongation at break is 36 ± 1%, and is higher than general degradable film, satisfies the film strength requirement.

Claims (1)

1. the preparation method of a high-strength degradable laminated film is characterized in that may further comprise the steps:

A, in the soy bean proteinous soln of 20～50g/L, add polyvinyl alcohol and toughener, dissolve and stir, then add vinyl acetic monomer, stir; The mass ratio of wherein said polyvinyl alcohol and soybean protein is 1:1～1.5; Described toughener is the carboxymethyl cellulose of 1:1～1.5 and the mixture of husky punt-pole glue by mass ratio, and addition is 0.5～2g/L;

B, then to regulate pH be 6～7, is heated to 75～90 ℃ and add the glycerine of 12～20g/L, reaction 1～2h;

C, reaction vessel vacuumized after, reaction product is filmed, and drying obtains film.