A cassava starch adhesive additive composition and a method for preparing the same

Abstract

The application discloses a cassava starch glue additive composition and a preparation method thereof in the technical field of material preparation, and comprises the following components in parts by weight: modified cassava starch 150 parts, modified zein fiber 30-50 parts, 10% sodium hydroxide solution 10-20 parts, sodium chloride 0.1-0.15 parts, borax 5-10 parts, water 250-300 parts, and sodium carboxymethyl cellulose 0.3-0.5 parts; the modified cassava starch is a product obtained after pre-gelatinized cassava starch is crosslinked with sodium trimetaphosphate; and the modified zein fiber is a zein fiber obtained after PEEK modification. The waterproof property, heat resistance and adhesion of the glue are improved by modifying the cassava starch and adding the modified zein fiber, so that the waterproof property, heat resistance and adhesion strength of the cassava starch glue additive composition are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material preparation, and particularly relates to a cassava starch glue additive composition and a preparation method thereof. BACKGROUND

[0002] Starch can be used as a raw material for making glue, and after modification through pre-gelatinization, oxidation and other means, starch can have more excellent performance; the ratio of amylopectin to amylose in cassava starch is as high as 80:20, and cassava starch has very high peak viscosity and is a good raw material for making glue; PEEK (polyether ether ketone) is a special engineering plastic with excellent properties such as high temperature resistance, stable chemical structure and hydrolysis resistance, and is applied to the manufacturing of mechanical parts and the field of aerospace; through modification of PEEK, the combination of PEEK with other materials can be realized, and the comprehensive performance can be improved; the existing environment-friendly starch glue has poor adhesion, and the use effect is poor at high temperature; in the use process, the starch glue is easy to be delaminated when contacting with water; therefore, in view of the above problems, it is a key technical problem to be solved in the field at present to provide a starch glue with good waterproofness, adhesion and heat resistance.

[0003] The existing technology mainly has the following problems:

[0004] 1. The existing starch glue on the market has poor heat resistance;

[0005] 2. The existing starch glue on the market has poor adhesion;

[0006] 3. The existing starch glue on the market has poor waterproofness. SUMMARY

[0007] In view of the above situation, in order to overcome the defects of the prior art, the application provides a preparation method of a cassava starch glue additive composition, the modification of cassava starch is performed, and modified corn protein fiber is added to solve the problems of poor heat resistance, poor waterproofness and poor adhesion of the starch glue, and thus the technical effect of the cassava starch glue additive composition having good heat resistance, waterproofness and adhesion is realized.

[0008] In order to achieve the above purpose, the technical scheme adopted by the application is as follows: the application provides a cassava starch glue additive composition, which comprises the following components in parts by weight: modified cassava starch 150 parts, modified corn protein fiber 30-50 parts, 10% sodium hydroxide solution 10-20 parts, sodium chloride 0.1-0.15 parts, borax 5-10 parts, water 250-300 parts, and sodium carboxymethyl cellulose 0.3-0.5 parts.

[0009] The modified cassava starch is a product obtained after pre-gelatinized cassava starch is crosslinked with sodium trimetaphosphate, and specifically comprises the following steps:

[0010] (1) Weigh cassava starch and dissolve it in distilled water, heat and stir, dry, and grind to 200 mesh to obtain pregelatinized cassava starch;

[0011] (2) Weigh the pregelatinized cassava starch obtained in step (1) and sodium trimetaphosphate and dissolve them in distilled water, adjust the pH to 11, and mix uniformly to obtain a sample;

[0012] (3) Put the sample obtained in step (2) into an extruder, dry, cool, and grind to 100 mesh to obtain modified cassava starch.

[0013] Preferably, in step (1), the heating temperature is 70-80℃, the stirring speed is 80-100r / min, and the stirring time is 0.5h; dry at 35-40℃;

[0014] Preferably, in step (2), the weight ratio of sodium trimetaphosphate to cassava starch is 1:60-100; the weight ratio of distilled water to pregelatinized cassava starch is 3:8;

[0015] Preferably, in step (3), the extrusion temperature is 60-70℃, the screw speed of the extruder is 100-120r / min; the drying temperature is 25-35℃.

[0016] The modified cassava starch is obtained by first pregelatinizing and then crosslinking, realizing the modification of cassava starch; the pregelatinization of cassava starch breaks the hydrogen bonds between starch molecules in hot water, shortens the length of starch molecular chains, changes the structure of starch molecules, and increases the solubility of pregelatinized cassava starch; due to the pregelatinization, the crystal lattice structure inside the starch granules is partially destroyed, the crosslinking agent more easily enters the interior of the starch granules and crosslinks with the starch, the alcohol hydroxyl groups of the starch form ester bonds with the multi-functional groups of sodium trimetaphosphate to form a multi-dimensional spatial network structure, the intermolecular forces of the starch are enhanced, and the adhesion and heat resistance of the modified cassava starch are enhanced.

[0017] The modified zein fiber is a zein fiber modified by PEEK (polyether ether ketone), specifically including the following steps:

[0018] [1] Mix dry PEEK with concentrated sulfuric acid uniformly, heat and react, cool and wash, filter and dry to obtain SPEEK;

[0019] [2] Dissolve zein and SPEEK in N-methyl pyrrolidone, stir under heating conditions to obtain a mixed solution;

[0020] [3] Take the mixed solution in step [2] above into a syringe, and prepare a fiber embryo by electrospinning technology, and vacuum dry to obtain a modified zein fiber.

[0021] Preferably, in step 【1】, drying is carried out at 80℃ for 14-16h; the molar concentration of concentrated sulfuric acid is 98%, the mass-volume ratio of PEEK to concentrated sulfuric acid is 1:20; the heating temperature is 60℃, and the reaction time is 6h;

[0022] Preferably, in step 【1】, ice water cooling is used, and the volume ratio of ice water to concentrated sulfuric acid is 3:1; distilled water is used for washing until the pH is 7; and drying is carried out at 80℃ for 24h;

[0023] Preferably, in step 【2】, the molar ratio of SPEEK to zein powder is 1:1, and the weight ratio of SPEEK to N-methylpyrrolidone is 1:4; the heating temperature is 45-60℃, and stirring is carried out at a stirring speed of 500r / min for 1h;

[0024] Preferably, in step 【3】, electrospinning is carried out at an electrospinning voltage of 15kv, a pole distance of 12cm, and room temperature, and the humidity is kept at about 50%; the vacuum drying temperature is 90℃, and the drying time is 6h.

[0025] The modified zein fiber is chemically modified by zein and SPEEK, so that the SPEEK is combined on the surface of the zein fiber, and the heat resistance and hydrophobicity of the modified zein fiber are enhanced; the zein fiber has hydrophobicity and stability, the PEEK has a stable chemical structure, the PEEK is treated by sulfonation to obtain the SPEEK, the SPEEK retains the carbonyl groups in the PEEK molecules, so that the SPEEK exhibits good heat resistance and oxidation resistance under high temperature and limited oxygen conditions; the molecular chain of the SPEEK contains polar sulfonic acid groups, which can form hydrogen bonds with the hydroxyl groups of the zein, so that strong intermolecular forces are generated, the SPEEK is better combined on the zein fiber, and the two together form the modified zein fiber, which has good heat resistance and hydrophobicity.

[0026] The application further provides a preparation method of the cassava starch glue water additive composition.

[0027] The modified cassava starch, sodium hydroxide, modified zein fiber, sodium chloride, borax and carboxymethyl cellulose sodium are dissolved in distilled water, heated and stirred, cooled and placed to prepare the cassava starch glue water additive composition.

[0028] Preferably, the reaction temperature is 75°C, the stirring speed is 150-200r / min, the stirring time is 1.5h, and the standing time is 2h.

[0029] The application has the following beneficial effects:

[0030] The application realizes the improvement of heat resistance, adhesion and water resistance of the cassava starch glue water additive composition by pre-gelatinization and cross-linking treatment of cassava starch and modification of corn protein fiber with PEEK; the hydrogen bonds between cassava starch molecules are destroyed, the crystal lattice structure inside the starch particles is partially destroyed, the cross-linking agent is more easily introduced into the inside of the starch particles to cross-link with the starch, the modified cassava starch molecules form a multi-dimensional space network structure, the interaction between the starches is stronger, and the heat resistance and adhesion of the starch are enhanced; the modified corn protein fiber is modified by introducing SPEEK, PEEK is sulfonated to obtain SPEEK, the carbonyl groups in the PEEK molecules are retained, the heat resistance is achieved, the sulfonic acid groups on the SPEEK can form hydrogen bonds with the hydroxyl groups on the corn protein, strong intermolecular forces are generated, the SPEEK is better combined on the corn protein fiber, and the heat resistance and hydrophobicity of the modified corn protein fiber are enhanced; the modified corn protein fiber is added to the cassava starch glue water additive composition, the modified corn protein fiber plays a filling and strengthening role, the water resistance and heat resistance of the cassava starch glue water additive composition are enhanced, and the adhesion is also enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is the solid content experimental result graph of the cassava starch glue water additive composition prepared in examples 1-4 and comparative examples 1-2 of the application;

[0032] Figure 2 is the initial adhesion experimental result graph of the cassava starch glue water additive composition prepared in examples 1-4 and comparative examples 1-2 of the application;

[0033] Figure 3 is the holding adhesion experimental result graph of the cassava starch glue water additive composition prepared in examples 1-4 and comparative examples 1-2 of the application;

[0034] Figure 4 is the water resistance experimental result graph of the cassava starch glue water additive composition prepared in examples 1-4 and comparative examples 1-2 of the application;

[0035] Figure 5 is the high-temperature adhesion strength experimental result graph of the cassava starch glue water additive composition prepared in examples 1-4 and comparative examples 1-2 of the application;

[0036] Figure 6 is the reaction principle diagram of the SPEEK prepared by sulfonization of PEEK in examples 1-4 of the application;

[0037] Figure 7Fig. 1 is a SEM image of the section of the zein fiber in Example 1 of the present application.

[0038] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and together with the description serve to explain the present application, and do not limit the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art. In addition, any method and material similar or equivalent to those described herein can be used in the present application. The preferred methods and materials described herein are only for demonstration, but cannot limit the content of the present application.

[0041] In the following examples, the experimental methods are all conventional methods unless otherwise specified. In the following examples, the test materials used are all purchased from commercial channels unless otherwise specified.

[0042] Cassava starch CasNo: 9005-25-8, purchased from Shanghai Jizhisheng Biotechnology Co., Ltd., item number 22750-500g;

[0043] Sodium trimetaphosphate CasNo: 7785-84-4, purchased from Shanghai Macklin Biotechnology Co., Ltd., item number T819378-500g;

[0044] Distilled water CasNo: 7732-18-5, purchased from Shanghai Jinpan Biotechnology Co., Ltd., item number 268300025;

[0045] Zein CasNo: 9010-66-6, purchased from Shanghai Jinpan Biotechnology Co., Ltd., item number 179310025;

[0046] PEEK CasNo: 29658-26-2, purchased from Shanghai Macklin Biotechnology Co., Ltd., item number P909311-100g;

[0047] N-methyl pyrrolidone CasNo: 872-50-4, purchased from Beijing Inokai Technology Co., Ltd., item number A28738;

[0048] Concentrated sulfuric acid, Cas No: 7664-93-9, purchased from Shanghai Jinpan Biotechnology Co., Ltd., item number 124230025;

[0049] Sodium hydroxide solution CasNo: 1310-73-2, purchased from Beijing Innocare Technology Co., Ltd., item number A53741;

[0050] Sodium chloride CasNo:7647-14-5, purchased from Beijing Innocare Technology Co., Ltd., item number A63214;

[0051] Borax CasNo:1303-96-4, purchased from Beijing Innocare Technology Co., Ltd., item number A80055;

[0052] Sodium carboxymethyl cellulose (Cas No: 9085-26-1), purchased from Shanghai Maclean Biochemical Technology Co., Ltd., item number C835846-2.5kg.

[0053] Example 1

[0054] A cassava starch adhesive additive composition comprises the following components in parts by weight: 150 parts modified cassava starch, 30 parts modified zein cellulose, 10 parts sodium hydroxide solution (10% by weight), 0.1 parts sodium chloride, 5 parts borax, 250 parts water, and 0.3 parts sodium carboxymethyl cellulose.

[0055] The modified cassava starch is a product obtained by cross-linking pregelatinized cassava starch with sodium tripolyphosphate, specifically including the following steps:

[0056] (1) Weigh out cassava starch and dissolve it in distilled water. Heat the water to 70°C and stir for 0.5 h at a stirring speed of 80 r / min. Dry the cassava starch at 35°C and grind it to 200 mesh to obtain pregelatinized cassava starch.

[0057] (2) Weigh the pregelatinized cassava starch and sodium tripolyphosphate obtained in step 1 and dissolve them in distilled water. The weight ratio of sodium tripolyphosphate to cassava starch is 1:60, and the weight ratio of water to cassava starch is 3:8. Adjust the pH to 11, mix well, and obtain the sample.

[0058] (3) The sample obtained in step (2) is placed in an extruder and extruded. The screw speed of the extruder is 100 r / min and the temperature inside the extruder is set to 60℃. The sample is dried, cooled and ground to 100 mesh at 25℃ to obtain modified cassava starch.

[0059] The modified zein fiber is a zein fiber obtained by PEEK (polyether ether ketone) modification, specifically including the following steps:

[0060] 【1】PEEK is dried at 80℃ for 14h, PEEK is mixed with concentrated sulfuric acid with molar concentration of 98% uniformly, the mass-volume ratio of PEEK and concentrated sulfuric acid is 1:20, the reaction is carried out at 60℃ for 6h, ice water is used for cooling, the volume ratio of ice water and concentrated sulfuric acid is 3:1, distilled water is used for washing until pH is 7, after filtration, drying is carried out at 80℃ for 24h, and SPEEK is prepared;

[0061] 【2】Zein and SPEEK are dissolved in N-methyl pyrrolidone, the molar ratio of SPEEK and zein powder is 1:1, the weight ratio of SPEEK and N-methyl pyrrolidone is 1:4, stirring is carried out at a heating temperature of 45℃ and a stirring speed of 500r / min for 1h, and a mixed solution is obtained;

[0062] 【3】The mixed solution in the above step 【2】 is taken in a syringe, the voltage of electrospinning is 15kv, the pole distance is 12cm, the temperature of electrospinning is room temperature, the humidity is kept at about 50%, a fiber embryo is prepared by electrospinning technology, and the modified zein fiber is prepared by vacuum drying at 90℃ for 6h.

[0063] The application also provides a preparation method of the cassava starch glue water additive composition, and specifically comprises the following steps:

[0064] The modified cassava starch, the sodium hydroxide solution with a mass fraction of 10%, the modified zein fiber, sodium chloride, borax and carboxymethyl cellulose sodium are dissolved in distilled water, stirring is carried out at a temperature of 75℃ and a stirring speed of 150r / min for 1.5h, cooling and standing are carried out for 2h, and the cassava starch glue water additive composition is prepared.

[0065] Example 2

[0066] A cassava starch glue water additive composition comprises the following components in parts by weight: modified cassava starch 150 parts, modified zein fiber 50 parts, sodium hydroxide solution with a mass fraction of 10% 20 parts, sodium chloride 0.1 part, borax 5 parts, water 250 parts and carboxymethyl cellulose sodium 0.3 part.

[0067] The modified cassava starch is a product obtained after crosslinking of pre-gelatinized cassava starch and sodium trimetaphosphate, and specifically comprises the following steps:

[0068] (1) cassava starch is weighed and dissolved in distilled water, the heating temperature is 80℃, stirring is carried out at a stirring speed of 100r / min for 0.5h, drying is carried out at 40℃, and grinding is carried out to 200 meshes, and pre-gelatinized cassava starch is obtained;

[0069] (2) The pregelatinized tapioca starch obtained in step 1 and sodium trimetaphosphate are weighed and dissolved in distilled water, the weight ratio of sodium trimetaphosphate to tapioca starch is 1:100, the weight ratio of water to tapioca starch is 3:8, the pH is adjusted to 11, and the mixture is uniformly mixed to obtain a sample;

[0070] (3) The sample obtained in step (2) is placed into an extruder, the screw rotation speed of the extruder is 120 r / min, the temperature in the extruder is set to 70℃, and the sample is dried, cooled, and ground to 100 mesh at 25℃ to obtain modified tapioca starch.

[0071] The modified zein fiber is a zein fiber modified by PEEK (polyether ether ketone), and specifically includes the following steps:

[0072] [1] PEEK is dried at 80℃ for 16h, PEEK is uniformly mixed with concentrated sulfuric acid with a molar concentration of 98%, the mass-volume ratio of PEEK to concentrated sulfuric acid is 1:20, and the mixture is reacted at 60℃ for 6h, cooled with ice water, the volume ratio of ice water to concentrated sulfuric acid is 3:1, washed with distilled water until the pH is 7, filtered, and dried at 80℃ for 24h to obtain SPEEK;

[0073] [2] Zein and SPEEK are dissolved in N-methyl pyrrolidone, the molar ratio of SPEEK to zein powder is 1:1, and the weight ratio of SPEEK to N-methyl pyrrolidone is 1:4, the mixture is stirred at a heating temperature of 45℃ and a stirring speed of 500 r / min for 1h to obtain a mixed solution;

[0074] [3] The mixed solution in step [2] is taken into a syringe, the voltage for electrospinning is 15kv, the electrode distance is 12cm, the temperature for electrospinning is room temperature, the humidity is maintained at about 50%, a fiber embryo is prepared by electrospinning technology, and the modified zein fiber is prepared by vacuum drying at 90℃ for 6h.

[0075] The application also provides a preparation method of the tapioca starch glue water additive composition, specifically including the following steps:

[0076] The modified tapioca starch, 10% sodium hydroxide solution, modified zein fiber, sodium chloride, borax, and carboxymethyl cellulose sodium are dissolved in distilled water, stirred at a temperature of 75℃ and a stirring speed of 200 r / min for 1.5h, and cooled and placed for 2h to prepare the tapioca starch glue water additive composition.

[0077] Example 3

[0078] A cassava starch glue additive composition, comprising the following components by weight: modified cassava starch 150 parts, modified zein fiber 50 parts, 10% sodium hydroxide solution 10 parts, sodium chloride 0.1 part, borax 5 parts, water 250 parts, sodium carboxymethyl cellulose 0.5 parts.

[0079] The modified cassava starch is a product obtained after cross-linking of pre-gelatinized cassava starch and sodium trimetaphosphate, and specifically comprises the following steps:

[0080] (1) cassava starch is weighed and dissolved in distilled water, the heating temperature is 70°C, and stirring is carried out at a stirring speed of 80 r / min for 0.5 h, and then dried at 35°C, ground to 200 mesh to obtain pre-gelatinized cassava starch;

[0081] (2) the pre-gelatinized cassava starch obtained in step 1 and sodium trimetaphosphate are weighed and dissolved in distilled water, the weight ratio of sodium trimetaphosphate to cassava starch is 1:80, the weight ratio of water to cassava starch is 3:8, the pH is adjusted to 11, and the mixture is uniformly mixed to obtain a sample;

[0082] (3) the sample obtained in step (2) is placed in an extruder and extruded, the screw rotation speed of the extruder is 120 r / min, the temperature in the extruder is set to 60°C, and then dried, cooled, and ground to 100 mesh at 25°C to obtain modified cassava starch.

[0083] The modified zein fiber is a zein fiber modified by PEEK (polyether ether ketone), and specifically comprises the following steps:

[0084] [1] PEEK is dried at 80°C for 14 h, PEEK is uniformly mixed with concentrated sulfuric acid with a molar concentration of 98%, the mass-volume ratio of PEEK to concentrated sulfuric acid is 1:20, and the mixture is reacted at 60°C for 6 h, cooled with ice water, the volume ratio of ice water to concentrated sulfuric acid is 3:1, washed with distilled water until the pH is 7, filtered, and then dried at 80°C for 24 h to obtain SPEEK;

[0085] [2] zein and SPEEK are dissolved in N-methyl pyrrolidone, the molar ratio of SPEEK to zein powder is 1:1, and the weight ratio of SPEEK to N-methyl pyrrolidone is 1:4, the mixture is stirred at a heating temperature of 45°C and a stirring speed of 500 r / min for 1 h to obtain a mixed solution;

[0086] [3] the mixed solution in step [2] above is taken in a syringe, the voltage for electrospinning is 15kv, the electrode distance is 12 cm, the temperature for electrospinning is room temperature, the humidity is maintained at about 50%, a fiber embryo is prepared by electrospinning technology, and then vacuum dried at 90°C for 6 h to obtain modified zein fiber.

[0087] The application further provides a preparation method of the cassava starch glue additive composition, and specifically comprises the following steps:

[0088] The modified cassava starch, 10% sodium hydroxide solution, modified zein fiber, sodium chloride, borax and sodium carboxymethyl cellulose are dissolved in distilled water, stirred at a temperature of 75℃ and a stirring speed of 150r / min for 1.5h, cooled and placed for 2h, and a cassava starch glue additive composition is prepared.

[0089] Example 4

[0090] The cassava starch glue additive composition comprises the following components in parts by weight: 150 parts of modified cassava starch, 50 parts of modified zein fiber, 20 parts of 10% sodium hydroxide solution, 0.15 parts of sodium chloride, 10 parts of borax, 300 parts of water and 0.5 parts of sodium carboxymethyl cellulose.

[0091] The modified cassava starch is a product obtained by crosslinking pre-gelatinized cassava starch and sodium trimetaphosphate, and specifically comprises the following steps:

[0092] (1) The cassava starch is weighed and dissolved in distilled water, heated to a temperature of 80℃, stirred at a stirring speed of 100r / min for 0.5h, dried at 40℃, and ground to 200 meshes to obtain pre-gelatinized cassava starch;

[0093] (2) The pre-gelatinized cassava starch obtained in step 1 and sodium trimetaphosphate are weighed and dissolved in distilled water, the weight ratio of sodium trimetaphosphate to cassava starch is 1:100, the weight ratio of water to cassava starch is 3:8, the pH is adjusted to 11, and the mixture is uniformly mixed to obtain a sample;

[0094] (3) The sample obtained in step (2) is put into an extruder, the screw rotation speed of the extruder is 120r / min, the temperature in the extruder is set to 70℃, and the sample is dried, cooled and ground to 100 meshes at 35℃ to obtain modified cassava starch.

[0095] The modified zein fiber is a zein fiber modified by PEEK (polyether ether ketone), and specifically comprises the following steps:

[0096] 【1】PEEK is dried at 80℃ for 16h, PEEK is uniformly mixed with concentrated sulfuric acid with a molar concentration of 98%, the mass-volume ratio of PEEK to concentrated sulfuric acid is 1:20, the mixture is reacted at 60℃ for 6h, the mixture is cooled by ice water, the volume ratio of ice water to concentrated sulfuric acid is 3:1, the mixture is washed by distilled water until the pH is 7, the mixture is filtered, and the filter is dried at 80℃ for 24h to obtain SPEEK.

[0097] [2] Dissolve zein and SPEEK in N-methylpyrrolidone. The molar ratio of SPEEK to zein powder is 1:1, and the weight ratio of SPEEK to N-methylpyrrolidone is 1:4. Stir for 1 hour at a heating temperature of 45℃ and a stirring speed of 500r / min to obtain a mixture.

[0098] [3] Take the mixture from step [2] into a syringe. The electrospinning voltage is 15kv, the electrode distance is 12cm, the electrospinning temperature is room temperature, and the humidity is kept at about 50%. The fiber preform is obtained by electrospinning technology and vacuum dried at 90℃ for 6h to obtain modified corn glycol fiber.

[0099] This invention also provides a method for preparing a cassava starch adhesive additive composition, specifically comprising the following steps:

[0100] Modified cassava starch, 10% sodium hydroxide solution, modified zein fiber, sodium chloride, borax, and sodium carboxymethyl cellulose were dissolved in distilled water and stirred for 1.5 hours at 75°C and 200 r / min. The mixture was then cooled and allowed to stand for 2 hours to prepare a cassava starch adhesive additive composition.

[0101] Comparative Example 1

[0102] This comparative example provides a cassava starch adhesive additive composition, which differs from Example 1 only in that it does not contain modified zein fiber in any of its components, while the remaining components and their contents are the same as in Example 1.

[0103] Comparative Example 2

[0104] This comparative example provides a cassava starch adhesive additive composition, which differs from Example 1 in that only the modified cassava starch is replaced with ordinary cassava starch in all components, while the remaining components and their contents are the same as in Example 1.

[0105] Experimental Example

[0106] 1. Solid content experiment

[0107] Take 1g of each of the samples from Examples 1-4 and Comparative Examples 1-2, heat them in a forced-air constant temperature oven at 100~105℃ for 175~185min, and then place them in a desiccator containing color-changing silica gel to cool to room temperature. Measure the mass of the sample after heating and calculate the mass ratio of the sample before and after heating. The formula is: X=(m1 / m2)*100%, where X is the content of non-volatile matter, %, m1 is the mass of the sample after heating (g), and m2 is the mass of the sample before heating (g).

[0108] 2. Initial viscosity test

[0109] The samples of Examples 1-4 and Comparative Examples 1-2 were made into adhesive tapes, which were placed without overlapping each other for more than 2 hours under the conditions of a test temperature of 21-25°C and a relative humidity of 40-60%; a ball rolling test was performed using a specified ball, and the test results were recorded.

[0110] 3. Holding adhesion test

[0111] The samples of Examples 1-4 and Comparative Examples 1-2 were made into adhesive tapes, which were attached to test boards, and the test boards were placed under the conditions of a temperature of 21-25°C and a relative humidity of 60-70% for 20 minutes. The test boards were vertically fixed to a test frame and placed in a test environment, and the start time of the test was recorded. After a specified time was reached, the weight was removed, and the time at which the test sample fell off the test board was recorded.

[0112] 4. Waterproof test

[0113] Ten grams of the samples of Examples 1-4 and Comparative Examples 1-2 were taken, and two pieces of wood boards of the same size were taken. The wood boards were coated with 150 g / m 2 The two contact surfaces were overlapped and pressed, and a pressure of 1 MPa was applied to the contact surfaces. The wood boards were assembled at room temperature for 12 hours, and then the pressure was removed and the wood boards were placed for another 12 hours. The wood boards were immersed in water at 30-35°C, and the time at which the adhesive was separated was measured, and the test results were recorded.

[0114] 5. High-temperature adhesion strength test

[0115] Ten grams of the samples of Examples 1-4 and Comparative Examples 1-2 were taken, and two pieces of wood boards of the same size were taken. The wood boards were coated with 150 g / m 2 The two contact surfaces were overlapped and pressed, and a pressure of 1 MPa was applied to the contact surfaces. The wood boards were assembled at room temperature for 12 hours, and then the pressure was removed and the wood boards were placed for another 12 hours. The wood boards were immersed in water at 30-35°C, and the time at which the adhesive was separated was measured, and the test results were recorded.

[0116] Results analysis

[0117] Figure 1The solid content experimental results of the cassava starch glue water additive compositions prepared in the embodiments 1-4 and the comparative examples 1-2 are shown in the figure, the solid contents of the embodiments 1-4 are all higher than 35%, which are higher than those of the comparative examples 1-2, and the decrease of the solid content is mainly caused by the evaporation of water; compared with the comparative example 1, the zein fibers and the surface SPEEK molecules in the modified zein fibers both have good heat resistance, under the heating condition, the modified zein fibers can absorb more heat, thereby reducing the influence of the heat on the cassava starch glue water additive composition, playing a heat insulation protection role, the cassava starch glue water additive composition is heated more slowly, and the evaporation of water can be effectively reduced; compared with the comparative example 2, the modified cassava starch has a multi-dimensional network space structure, the interaction between the starch molecules is stronger, and the heat resistance of the starch is enhanced, so that the water volatilization is slow.

[0118] Figure 2 The initial adhesion experimental results of the cassava starch glue water additive compositions prepared in the embodiments 1-4 and the comparative examples 1-2 are shown in the figure, the initial adhesion of the embodiments 1-4 are all higher than those of the comparative examples 1-2, and it can be seen that the cassava starch glue water prepared in the application has good initial adhesion.

[0119] Figure 3 The holding adhesion experimental results of the cassava starch glue water additive compositions prepared in the embodiments 1-4 and the comparative examples 1-2 are shown in the figure, the holding adhesion of the embodiments 1-4 are all greater than 40h, which are higher than those of the comparative examples 1-2, and it can be seen that the cassava starch glue water prepared in the application has long-lasting adhesion.

[0120] According to the results of Figure 2 and Figure 3 , compared with the comparative example 1, the modified zein fibers have a filling and strengthening effect in the cassava starch glue water additive composition, the addition of the modified zein fibers leads to the increase of the specific surface area of the cassava starch glue water additive composition, the combination between the fibers and the glue water molecules is more closely, the addition of the modified zein fibers increases the friction between the cassava starch glue water additive composition and the rolling ball and the wood board, and the initial adhesion and the holding adhesion of the cassava starch glue water additive composition are enhanced; compared with the comparative example 2, the interaction between the starch molecules of the modified cassava starch is greater than that of the ordinary cassava starch, and the initial adhesion and the holding adhesion are enhanced.

[0121] Figure 4The waterproof experiment results of the cassava starch glue additive compositions prepared in examples 1-4 and comparative examples 1-2 are shown in the figure, and the waterproof time of examples 1-4 is greater than 55 minutes, and the waterproof effect is better than that of comparative examples 1-2; compared with comparative example 1, the modified zein fiber plays a filling and strengthening role in the cassava starch glue additive composition, the intermolecular combination is more closely, and the water molecules are not easy to enter the starch glue structure; at the same time, the SPEEK on the surface of the modified zein fiber has good waterproof property, the addition of the modified zein fiber reduces the position of the water molecules entering the starch structure, and the waterproof property of the cassava starch glue additive composition is improved; compared with comparative example 2, compared with cassava starch, the modified cassava starch forms a multi-dimensional space network structure between molecules, the molecular combination is more closely, the structure is more stable, and the water molecules are not easy to enter the starch structure, so the waterproof property of the cassava starch glue additive composition prepared from the modified cassava starch is better.

[0122] Figure 5 The high temperature bonding strength experiment results of the cassava starch glue additive compositions prepared in examples 1-4 and comparative examples 1-2 are shown in the figure, and the joints formed in examples 1-4 have better bonding strength, which is much higher than that of comparative examples 1-2, so the cassava starch glue prepared by the application has good high temperature bonding strength. Compared with comparative example 1, the modified zein fiber plays a heat insulation protection role in the cassava starch glue additive composition, the modified zein fiber introduces SPEEK, the SPEEK retains the carbonyl group in the PEEK molecule, so that it has good heat resistance under high temperature conditions, and the filling and strengthening effect of the modified zein fiber in the cassava starch glue additive composition enhances the adhesion, so the high temperature bonding strength of the cassava starch glue additive composition is higher; compared with comparative example 2, compared with cassava starch, the modified cassava starch forms a multi-dimensional space network structure between starch molecules, the molecular combination is more closely, and the starch molecular structure is more stable, so the high temperature bonding strength of the cassava starch glue additive composition prepared from the modified cassava starch is greater.

[0123] Figure 6 is the reaction principle diagram of SPEEK prepared by sulfonating PEEK in examples 1-4 of the application, as shown in the figure, PEEK is reacted with concentrated sulfuric acid at 60 DEG C for 6h to obtain SPEEK.

[0124] Figure 7 is the SEM image of the cross section of the zein fiber in examples 1-4 of the application, as shown in the figure, the SPEEK molecules are distributed on the surface of the zein fiber to realize modification.

[0125] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and spirit of the application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

[0126] The above description of the application and its embodiments is not restrictive, and the embodiments shown in the drawings are only one of the embodiments of the application, and the actual application is not limited thereto. In general, if a person skilled in the art is inspired by it, without departing from the purpose of the application, without creative design, similar ways and embodiments of the technical solution should belong to the protection scope of the application.

Claims

1. A cassava starch glue additive composition characterized by: The components include the following weight parts: modified cassava starch 150 parts, modified zein fiber 30-50 parts, 10% sodium hydroxide solution 10-20 parts, sodium chloride 0.1-0.15 parts, borax 5-10 parts, water 250-300 parts, and sodium carboxymethyl cellulose 0.3-0.5 parts; the modified cassava starch is a product obtained by crosslinking pre-gelatinized cassava starch with sodium trimetaphosphate, and the modified zein fiber is a zein fiber obtained by modification with PEEK; The preparation method of the modified zein fiber specifically includes the following steps: 【1】Dry PEEK is mixed with concentrated sulfuric acid, heated for reaction, cooled and washed, filtered, and dried to obtain SPEEK; 【2】Zein and SPEEK are dissolved in N-methyl pyrrolidone, and stirred under heating to obtain a mixed solution; 【3】The mixed solution in step 【2】 is taken in a syringe, and a fiber embryo is prepared by electrospinning technology, and vacuum drying is performed to obtain modified zein fiber.

2. A cassava starch adhesive additive composition according to claim 1, characterized by: The preparation method of the modified cassava starch specifically includes the following steps: (1) Cassava starch is dissolved in distilled water, heated, stirred, dried, and ground to 200 mesh to obtain pre-gelatinized cassava starch; (2) The pre-gelatinized cassava starch obtained in step (1) and sodium trimetaphosphate are dissolved in distilled water, the pH is adjusted to 11, and the mixture is uniformly mixed to obtain a sample; (3) The sample obtained in step (2) is placed in an extruder for extrusion, dried, cooled, and ground to 100 mesh to obtain modified cassava starch.

3. A cassava starch adhesive additive composition according to claim 2, characterized by: In step (1), the heating temperature is 70-80℃, the stirring speed is 80-100 r / min, and the stirring time is 0.5 h; and the drying is performed at 35-40℃.

4. A cassava starch adhesive additive composition according to claim 3, characterised by: In step (2), the weight ratio of sodium trimetaphosphate to cassava starch is 1:60-100, and the weight ratio of distilled water to pre-gelatinized cassava starch is 3:8; in step (3), the extrusion temperature is 60-70℃, the screw rotation speed of the extruder is 100-120 r / min, and the drying temperature is 25-35℃.

5. A cassava starch adhesive additive composition according to claim 4, characterised in that: In step 【1】, drying is performed at 80℃ for 14-16 h; the molar concentration of concentrated sulfuric acid is 98%, the mass-volume ratio of PEEK to concentrated sulfuric acid is 1:20; the heating temperature is 60℃, the reaction time is 6 h; ice water cooling is performed, the volume ratio of ice water to concentrated sulfuric acid is 3:1; distilled water is used for washing until the pH is 7; and drying is performed at 80℃ for 24 h.

6. A cassava starch adhesive additive composition according to claim 5, characterised in that: In step 【2】, the molar ratio of SPEEK to zein powder is 1:1, and the weight ratio of SPEEK to N-methyl pyrrolidone is 1:4; the heating temperature is 45-60℃, and stirring is performed at a stirring speed of 500 r / min for 1 h.

7. A cassava starch adhesive additive composition according to claim 6, characterised by: In step 【3】, electrospinning is performed at an electrospinning voltage of 15 kv, a pole distance of 12 cm, and a room temperature, and the humidity is maintained at about 50%; vacuum drying is performed at a temperature of 90℃ for 6 h.

8. A process for the preparation of a cassava starch adhesive additive composition according to any one of claims 1 to 7, characterized in that: Specifically includes the following steps: Modified cassava starch, 10% sodium hydroxide solution, modified zein fiber, sodium chloride, borax, sodium hydroxymethyl cellulose are dissolved in distilled water, heated and stirred, cooled and placed, and a cassava starch glue water additive composition is prepared.

9. A process for the preparation of a cassava starch adhesive additive composition according to claim 8, characterized by: The heating temperature is 75°C, the stirring speed is 150-200r / min, the stirring time is 1.5h, and the standing time is 2h.

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