CN110115962A - A kind of synthetic method of silica grafting phenolic resin package reversible color change microcapsule - Google Patents

Abstract

The invention relates to a method for synthesizing reversible discoloration microcapsules wrapped with silicon dioxide grafted phenolic resin. The steps of the synthetic synthesis method of the present invention are as follows: (1) Preparation of composite emulsifier; (2) Synthesis of silica grafted phenolic resin coating material; (3) Preparation of shell core of reversible discoloration material; (4) Micro Synthesis of capsules. The invention specifically relates to a method for synthesizing reversible discoloration microcapsules wrapped with silica-grafted phenolic resin. The microcapsule synthesized by the invention has relatively low energy consumption in the technical process, good dispersibility, small particle size and is not easy to be damaged, and has high coating rate. The microcapsule discoloration temperature is about 35.5°C, the discoloration time is about 30s, the recoloring temperature is about 32°C, and the recoloring time is about 35s, blue at low temperature and transparent at high temperature, obviously forming a microcapsule structure. The microcapsules are regular and spherical, and the particle size is nanometer.

Description

A kind of synthesis method of reversible discoloration microcapsules coated with silica grafted phenolic resin

technical field

The invention relates to a method for synthesizing reversible discoloration microcapsules coated with silica-grafted phenolic resin, in particular to a method for synthesizing core-shell type silica-grafted phenolic resin-coated microcapsules of reversible organic heat-sensitive materials based on interfacial polymerization. Synthesis of capsules.

Background technique

Microcapsules are microscopic containers or packages with polymeric walls. Microcapsule granulation technology is to embed and seal solid, liquid or gas in a microcapsule to become a solid particle product. In recent years, microcapsule technology has been widely used in the immobilization of microorganisms, animal and plant cells, enzymes and other biologically active substances and chemical drugs. The commonly used microcapsules are alginic acid/polylysine microcapsules. Due to the complicated preparation technology and the long time of encapsulation process, it has a certain influence on the biological activity of the embedded material, and the price of polylysine is relatively expensive, thus limiting the use of this microcapsule.

The basic materials for preparing microcapsules usually have polyelectrolytes such as proteins, lipids and sugars. Chitosan is partially deacetylated chitin, which has excellent toughness and inertness, and is hydrophilic, non-toxic, porous, and uniform. At the same time, chitin is also very abundant in nature. In view of this, starting from the particularity of chitin, a natural polymer functional group, as well as the advantages of non-toxicity and hydrophilicity, this experiment obtained chitosan by deacetylation with concentrated alkali, and then obtained spherical chitosan by the above method. , and embed the yeast in the spherical chitosan by appropriate method to prepare microcapsules with good performance, and discuss the conditions of chitosan spheroidization, optimal conditions for embedding yeast, and chitosan as an immobilized microcapsule. The feasibility of the material carrier. Traditional microcapsule synthesis methods can be roughly divided into three categories: physical methods, physicochemical methods, and chemical methods. Commonly used physical methods include crushing method, mechanical alloy method and evaporation condensation method. Physical methods include spray drying method, spray freezing method, air suspension method, vacuum evaporation deposition method, complex coacervation method, multi-space centrifugation method, etc.; physical and chemical methods include Water phase separation method, oil phase separation method, capsule core exchange method, extrusion method, orifice method, powder bed method; chemical methods include interfacial polymerization method, in-situ polymerization method, molecular encapsulation method, radiation encapsulation method, etc.

Nanocapsules (nanocapsules) were first proposed by Narty et al. in the late 1970s, and generally refer to microcapsules with a particle size between 1-1000nm. Since nanocapsules are different from ordinary microcapsules mainly in particle size, when synthesizing nanocapsules, various factors affecting particle size should be analyzed to determine process parameters. The synthesis methods of nanocapsules are mainly chemical and physical chemical methods. Among them, Zhu Yinyan and others introduced the methods of synthesizing nanomicrocapsules in different colloidal systems, including interfacial polymerization and interfacial deposition. Recently, the synthesis of nano-microcapsules using electrodeless metals as wall materials has become a global hotspot. However, the obvious disadvantages of the general production of microcapsules are that the process is complex, the process has many synthesis steps, the production energy consumption is large, and it is easy to break, poor water resistance and dispersibility, and the particle size is generally large and uneven.

Contents of the invention

The purpose of the present invention is to synthesize a method for synthesizing core-shell silica-grafted phenolic resin-coated organic reversible discoloration heat-sensitive material microcapsules. The interfacial polymerization method can control the particle size in a smaller and more concentrated range . The particle size of the core-shell type silicon dioxide grafted phenolic resin coated organic heat-sensitive material microcapsules synthesized by the present invention can be controlled to 50-150nm, the particle size is small and the distribution is narrow, the dispersibility is good, and the energy consumption of the process is relatively low. And not easy to break, good water resistance.

A method for synthesizing reversible discoloration microcapsules coated with silica-grafted phenolic resin, the synthesis method specifically comprising the following steps:

(1) Preparation of composite emulsifier: under normal temperature, take 5g of n-hexane, 0.4g of Span-80 and 0.1g of OP-10 in a 100ml beaker, mix and stir for 10-20min to obtain solution A;

(2) Synthesis of silica-grafted phenolic resin coating material: at room temperature, take 0.1g sodium hydroxide and 3.5g resorcinol, add 100ml distilled water to a 200ml beaker, mix and stir for 10-20min, then add 6ml The silica sol was reacted for 30 minutes to obtain solution B;

(3) Preparation of reversible discoloration material shell core: the temperature is controlled at 55°C, crystal violet lactone, bisphenol A, and cetyl alcohol are poured into a four-necked bottle with a stirrer and heated to dissolve, and the stirring speed is set 600-800r/min, and add 6g formaldehyde solution and 0.1gOS-10, slowly drop solution A into the four-neck flask, the dropping speed is 30-40mL/min, after stirring for 30min, the emulsion C is obtained and cooled to room temperature;

(4) Synthesis of microcapsules: under normal temperature conditions, drop solution B into a four-necked bottle, the dropping rate is 3-4mL/min, the stirring speed is 600-800r/min, and after keeping for 5-6h, the core-shell is obtained Type silica-grafted phenolic resin coated organic reversible discoloration thermosensitive material microcapsules.

Synthetic method of the present invention has the following advantages:

(1) The present invention adopts thermoplastic silica-grafted phenolic resin to replace conventional thermosetting resin and ungrafted thermoplastic resin to synthesize microcapsules, so that the particle size is small and uniform, not easily damaged, and the coating rate is high;

(2) The preparation process of the microcapsules is basically room temperature, which is convenient for production operation and reduces production energy consumption.

Description of drawings

Fig. 1 is the SEM image of a synthetic method of silica-grafted phenolic resin-wrapped reversible discoloration microcapsules in Example 1.

Fig. 2 is an SEM image of a synthesis method of silica-grafted phenolic resin-wrapped reversible discoloration microcapsules in Example 2.

Fig. 3 is a SEM image of a synthesis method of silica-grafted phenolic resin-wrapped reversible discoloration microcapsules in Example 3.

Detailed ways

The above-mentioned content of the present invention will be further described in detail through specific implementation in the form of examples below.

Embodiment one:

(1) Synthesis of compound emulsifier: under normal temperature, take 5g of n-hexane, 0.4g of Span-80 and 0.1g of OP-10 in a 100ml beaker, mix and stir for 10-20min to obtain solution A;

(2) Synthesis of silica grafted phenolic resin coating material: at room temperature, take 0.1g sodium hydroxide and 3.5g resorcinol, add 80ml distilled water to a 200ml beaker, mix and stir for 10-20min, then add 1ml The silica sol was reacted for 30 minutes to obtain solution B;

(3) Synthesis of reversible discoloration material shell core: the temperature is controlled at 55°C, crystal violet lactone, bisphenol A, and cetyl alcohol are poured into a four-necked bottle with a stirrer and heated to dissolve, and the stirring speed is set 600-800r/min, and 6g of formaldehyde solution was added, and solution A was slowly added dropwise into a four-necked bottle at a rate of 30-40mL/min, and after stirring for 30min, emulsion C was obtained and cooled to room temperature;

(4) Synthesis of microcapsules: under normal temperature conditions, drop solution B into a four-necked bottle, the dropping rate is 3-4mL/min, the stirring speed is 600-800r/min, and after keeping for 5-6h, the core-shell is obtained Type silica-grafted phenolic resin coated organic color-changing heat-sensitive material microcapsules.

The microcapsules synthesized in this implementation case have a discoloration temperature of about 35.5°C, a discoloration time of about 30s, a recoloring temperature of about 32°C, and a recoloring time of about 35s. They are blue at low temperature and transparent at high temperature, with serious agglomeration.

Embodiment two:

(1) Synthesis of compound emulsifier: under normal temperature, take 5g of n-hexane, 0.4g of Span-80 and 0.1g of OP-10 in a 100ml beaker, mix and stir for 10-20min to obtain solution A;

(2) Synthesis of silica grafted phenolic resin coating material: at room temperature, take 0.1g sodium hydroxide and 3.5g resorcinol, add 80ml distilled water to a 100ml beaker, mix and stir for 10-20min, then add 5ml The silica sol was reacted for 30 minutes to obtain solution B;

(3) Synthesis of reversible discoloration material shell core: the temperature is controlled at 55°C, crystal violet lactone, bisphenol A, and cetyl alcohol are poured into a four-necked bottle with a stirrer and heated to dissolve, and the stirring speed is set 600-800r/min, and add 6g formaldehyde solution and 0.1gOS-10, slowly drop solution A into the four-neck flask, the dropping speed is 30-40mL/min, after stirring for 30min, the emulsion C is obtained and cooled to room temperature;

(4) Synthesis of microcapsules: under normal temperature conditions, drop solution B into a four-necked bottle, the dropping rate is 3-4mL/min, the stirring speed is 600-800r/min, and after keeping for 5-6h, the core-shell is obtained Type silica-grafted phenolic resin coated organic color-changing heat-sensitive material microcapsules.

The microcapsules synthesized in this implementation case have a discoloration temperature of about 35.5°C, a discoloration time of about 30s, a recoloring temperature of about 32°C, and a recoloring time of about 35s. They are blue at low temperature and transparent at high temperature, and the phenomenon of agglomeration is reduced.

Embodiment three:

(1) Preparation of composite emulsifier: under normal temperature, take 5g of n-hexane, 0.4g of Span-80 and 0.1g of OP-10 in a 100ml beaker, mix and stir for 10-20min to obtain solution A;

(2) Synthesis of silica grafted phenolic resin coating material: under normal temperature, take 0.1g sodium hydroxide and 3.5g resorcinol, add 80ml distilled water to a 200ml beaker, mix and stir for 10-20min, then add 6ml The silica sol was reacted for 30 minutes to obtain solution B;

(3) Synthesis of reversible discoloration material shell core: the temperature is controlled at 55°C, crystal violet lactone, bisphenol A, and cetyl alcohol are poured into a four-necked bottle with a stirrer and heated to dissolve, and the stirring speed is set 600-800r/min, and add 6g formaldehyde solution and 0.1gOS-10, slowly drop solution A into the four-neck flask, the dropping speed is 30-40mL/min, after stirring for 30min, the emulsion C is obtained and cooled to room temperature;

(4) Synthesis of microcapsules: under normal temperature conditions, drop solution B into a four-necked bottle, the dropping rate is 3-4mL/min, the stirring speed is 600-800r/min, and after keeping for 5-6h, the core-shell is obtained Type silica-grafted phenolic resin coated organic color-changing heat-sensitive material microcapsules.

The microcapsules synthesized in this implementation case have a discoloration temperature of about 35.5°C, a discoloration time of about 30s, a recoloring temperature of about 32°C, and a recoloring time of about 35s. They are blue at low temperature and transparent at high temperature, obviously forming a microcapsule structure.

Claims (4)

1. a kind of synthetic method of silicon dioxide grafted phenolic resin wrapping reversible discoloration microcapsules, it is characterized in that described method step is as follows: (1) Preparation of composite emulsifier: under normal temperature, take 5g n-hexane, 0.4g Span-80 and 0.1g OP-10 in a 100ml beaker, mix and stir for 10-20min to obtain solution A; (2) Synthesis of silica grafted phenolic resin coating material: at room temperature, take 0.1g sodium hydroxide and 3.5g resorcinol, add 100ml distilled water to a 200ml beaker, mix and stir for 10-20min, then add 6ml The silica sol was reacted for 30 minutes to obtain solution B; (3) Preparation of reversible discoloration material shell core: the temperature is controlled at 55°C, crystal violet lactone, bisphenol A, and cetyl alcohol are poured into a four-necked bottle with a stirrer and heated to dissolve, and the stirring speed is set 600-800r/min, add 6g formaldehyde solution and 0.1g OS-10, slowly drop solution A into the four-necked bottle at a rate of 30-40mL/min, stir for 30min, obtain emulsion C and cool down to room temperature; (4) Synthesis of microcapsules: Add solution B dropwise into a four-necked bottle at room temperature, the dropping rate is 3-4mL/min, the stirring speed is 600-800r/min, and keep for 5-6h to obtain the core-shell Type silica-grafted phenolic resin coated organic reversible discoloration thermosensitive material microcapsules. 2. The synthesis method of silica-grafted phenolic resin-wrapped reversible discoloration microcapsules according to claim 1, characterized in that the non-ionic surfactant Span-80 in the step (1) (3) , The mass ratio of OS-10 and OP-10 is 4:1:1. 3. A method for synthesizing reversible discoloration microcapsules coated with silica-grafted phenolic resin according to claim 1, characterized in that in the step (2), sodium hydroxide, silica sol and resorcinol The mass ratio is 1:70:35. 4. The synthesis method of silica-grafted phenolic resin-wrapped reversible discoloration microcapsules according to claim 1, characterized in that in the step (3), crystal violet lactone, bisphenol A, cetyl The mass ratio of alcohol is 1:3:20.