阅读说明：本技术 天然植物高分子淀粉的二阶式表面反应处理方法 (Two-stage surface reaction treatment method of natural plant high molecular starch ) 是由 吴勇 于 2018-08-07 设计创作，主要内容包括：本发明公开了天然植物高分子淀粉的二阶式表面反应处理方法；其有效改善了现有技术中,因淀粉的热塑性、相容性不佳,在加工制造热塑性淀粉塑料或热塑性淀粉改性塑料时随着淀粉用量的增加其机械和物理性能下降严重的问题。本发明提供的方法可以使淀粉的热塑性、相容性得到极大改善,可大大地提高加工制造热塑性淀粉塑料或热塑性淀粉改性塑料的机械和物理性能；同时绿色环保、生态安全。(The invention discloses a two-order surface reaction treatment method of natural plant high molecular starch; the method effectively solves the problem that the mechanical and physical properties of the starch are seriously reduced along with the increase of the using amount of the starch when thermoplastic starch plastic or thermoplastic starch modified plastic is processed and manufactured in the prior art due to poor thermoplasticity and compatibility of the starch. The method provided by the invention can greatly improve the thermoplasticity and the compatibility of the starch, and can greatly improve the mechanical and physical properties of the thermoplastic starch plastic or the thermoplastic starch modified plastic; meanwhile, the method is green, environment-friendly and ecologically safe.)

1. The second-order surface reaction treatment method of the natural plant high molecular starch is characterized in that: the surface of the natural plant high molecular starch reacts with one or more ecologically safe acids or anhydrides.

2. The surface reaction treatment method according to claim 1, characterized in that: in the surface reaction treatment, the weight percentage of the acid component (acid and acid anhydride) and the starch is 0-20% (the weight of the starch is 100).

3. The surface reaction treatment method according to claim 1, characterized in that: completely ecologically safe acids or anhydrides are used, for example organic acids such as citric acid, malic acid, stearic acid, acetic acid, etc., or anhydrides thereof.

4. The surface reaction treatment method according to claim 1, characterized in that: the two-step surface reaction is adopted, namely the reaction is carried out in a two-step mode.

5. The surface reaction treatment method according to claim 1, characterized in that: the reaction is controlled to occur on the surface of natural plant high molecular starch particles.

6. The surface reaction treatment method according to claim 1, characterized in that: in the first-stage reactor, keeping a set temperature, adding starch and stirring at a high speed; uniformly spraying acid or acid anhydride (such as citric acid) and a small amount of other additives into the starch under high-speed stirring, and uniformly mixing; the starch surface reacts with an acid or acid anhydride (e.g., citric acid). After the specified reaction time in the first stage reactor, the material is put into a second stage reactor for continuous reaction, and after the specified time in the second stage reactor, the starch with the surface treated is obtained.

7. The surface reaction treatment method according to claim 1, characterized in that: the temperature of the first-stage reactor is set to be 20-180 ℃, and the temperature in the second-stage reactor can be set according to the reaction requirement and the process relation.

8. The surface reaction treatment method according to claim 1, characterized in that: the material residence time of the first-stage reactor is set to be 2-120 minutes, and the material residence time of the second-stage reactor is set to be 2-120 minutes.

The technical field is as follows:

the invention relates to the processing and treatment of natural plant high molecular starch; in particular to a two-order surface reaction treatment method of natural plant high molecular starch.

Background art:

at present, the plastic waste is large in quantity and difficult to degrade, and the environment and the ecology are seriously influenced. Therefore, the application of biodegradable polymer materials is increasing. Compared with common plastic, the biodegradable high polymer material has high cost, great difficulty and complex processing technology; the application of the biodegradable high polymer material is limited to a great extent.

The natural plant high molecular starch has poor thermoplasticity and poor compatibility with other biodegradable high molecular materials due to the molecular structure of the natural plant high molecular starch. When the starch is used for processing and manufacturing thermoplastic starch plastics or thermoplastic starch modified plastics, the starch is generally subjected to coupling treatment, gelatinization treatment or direct use without treatment; the mechanical and physical properties of the thermoplastic starch plastics or thermoplastic starch modified plastics processed and manufactured in such a way are seriously reduced along with the increase of the using amount of starch, and improvement is urgently needed. The starch is natural plant polymer powder, is green and environment-friendly, is ecologically safe, has low price and good biodegradability, and if the performances of thermoplasticity, compatibility and the like of the starch can be effectively improved, the application of the biodegradable plastic, namely the ecologically friendly plastic, can be greatly improved, and the pollution caused by the production of waste general plastic can be reduced.

The invention content is as follows:

the invention provides a two-step surface reaction treatment method of natural plant high molecular starch, which is a method for modifying the surface of natural plant high molecular starch (such as starch) by the surface reaction of the natural plant high molecular powder and acid or acid anhydride in a two-step mode. The natural plant high molecular powder (starch) treated by the method greatly improves the thermoplasticity and the compatibility, thereby greatly improving the mechanical and physical properties of the thermoplastic starch plastic or the thermoplastic starch modified plastic.

The method of the invention is used for surface treatment of natural plant polymer powder (such as starch). The reaction is controlled to occur at the surface of the starch granules. Improve the thermoplasticity of natural plant polymer powder (such as starch), improve the compatibility of starch and other polymer materials, particularly biodegradable polymer materials, and improve various properties of the blend of starch and polymer materials.

In the first-stage reactor, keeping a set temperature, adding starch and stirring at a high speed; uniformly spraying acid or acid anhydride (such as citric acid) and a small amount of other additives into the starch under high-speed stirring, and uniformly mixing; the starch surface reacts with an acid or acid anhydride (e.g., citric acid). After a specified reaction time in the first stage reactor, the material is put into the second stage reactor and continues to react. After a prescribed time in the second stage reactor, the surface-treated starch is obtained.

The temperature of the first-stage reactor is set to be 20-180 ℃, and the temperature in the second-stage reactor can be set according to the reaction requirement and the process relation. The material residence time of the first-stage reactor is set to be 2-120 minutes, and the material residence time of the second-stage reactor is set to be 2-120 minutes.

In the reaction treatment, the acid component may be acid or acid anhydride (such as organic acid like citric acid, malic acid, stearic acid, maleic acid, etc. or acid anhydride thereof), preferably ecologically safe acid or acid anhydride (such as organic acid like citric acid, malic acid, stearic acid, acetic acid, etc. or acid anhydride thereof); the acid or acid anhydride may be used singly or in combination of two or more. The weight percentage of the acid component (acid and acid anhydride) and the starch is 0-20% (the weight of the starch is 100).

Compared with the prior art, the method provided by the invention can achieve the following technical effects:

1. the natural plant polymer powder (starch) treated by the method greatly improves the thermoplasticity and the compatibility, thereby greatly improving the mechanical and physical properties of the thermoplastic starch plastic or the thermoplastic starch modified plastic.

2. The method of the invention has high efficiency, energy saving and low manufacturing cost.

3. The method of the invention is used for processing starch, and the processing process is green and pollution-free; the treated starch does not contain harmful substances completely, and is ecological and safe.