Phytic acid modified starch flame retardant, its preparation method and application in semi-durable flame retardant fabric

Abstract

The application discloses a phytic acid modified starch flame retardant, a preparation method thereof and application of the phytic acid modified starch flame retardant in fabric semi-durable flame retardation, and belongs to the technical field of flame retardants. The preparation method of the phytic acid modified starch flame retardant is as follows: phytic acid and starch are placed in a reactor, and are reacted under heating for a certain time to obtain phytic acid modified starch; the starch is any one of corn starch, sweet potato starch, potato starch, cassava starch, glutinous rice starch, chestnut starch and mung bean starch. The phytic acid modified starch is arranged on fabric by using rolling baking technology, and the fabric is any one of cotton, polyester, polyester-cotton blended fabric, viscose, modal, lyocell, cotton-viscose blended fabric, nylon, wool, silk and the like. The flame retardation performance of the fabric after the flame retardant finishing treatment of the phytic acid modified starch is obviously improved; due to the excellent paste-making effect of the starch, the flame retardant can be adhered to the surface of the fabric, and certain flame retardation durability is given to the system. Compared with the phytic acid finished fabric, the strength retention is also obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flame retardants and fabric flame retardation technology, and in particular to the synthesis of phytic acid modified starch flame retardant and the construction of flame-retardant fabric. BACKGROUND

[0002] With the development of social economy, various fabrics, such as cotton, polyester, polyester-cotton blended fabric, viscose, lyocell, cotton-viscose blended fabric, wool, silk, etc., are used more and more widely in people's life. However, most of the fabrics have low limiting oxygen index and are extremely easy to burn in case of fire, endangering people's life and property safety. Therefore, it is crucial to develop washable flame-retardant fabric to improve the fire safety of fabrics.

[0003] At present, with the continuous enhancement of people's environmental awareness, green, pollution-free, efficient and environmentally friendly bio-based flame retardants have become the first choice. Common biomass materials such as starch, chitosan and tea polyphenol are widely studied because they contain multi-hydroxyl structures and have high carbon content, which can replace traditional petroleum-based charring agents. Phytic acid, as a biomass material with a high phosphorus content of 28%, can be used as an acid-catalyzed flame retardant with high flame retardant performance. Inspired by the application of starch in printing paste, the present application uses phytic acid and starch to obtain a flame retardant product through a simple reaction, which can impart semi-durable flame retardant effect to fabrics. In the flame retardant system of the present application, starch acts as a natural crosslinking agent, which adheres the flame retardant to the surface of the fabric through swelling and adhesion, and at the same time, the reaction between the hydroxyl groups in starch and phytic acid reduces the acidity of the system and reduces the impact on fabric strength. SUMMARY

[0004] To solve the problem of coordination between flame retardant performance and strength retention in existing fabric flame retardant technology, the present application provides a green, environmentally friendly and simple preparation method of reactive flame retardant using starch and phytic acid as raw materials, and uses it to prepare semi-durable flame-retardant fabric.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] A preparation method of phytic acid modified starch flame retardant, the steps are as follows:

[0007] Excess starch and phytic acid are mixed uniformly and subjected to esterification reaction at 60-150℃ to obtain phytic acid modified starch. The reaction temperature is preferably 80-130℃.

[0008] The mass ratio of starch to phytic acid in the step is 5:1-1:5, preferably 1:1, and the reaction time is 1-8h; the starch is any one of corn starch, sweet potato starch, potato starch, cassava starch, glutinous rice starch, chestnut starch and mung bean starch, and of course it can also be other starch that can be realized.

[0009] Use of phytic acid modified starch in flame-retardant fabric, the preparation process of the flame-retardant fabric is:

[0010] Preparation of phytic acid modified starch flame retardant solution, the fabric is soaked in the flame retardant solution, and the flame retardant is finished on the fabric by pad baking technology.

[0011] The specific steps are: the fabric is soaked in 40-500g / L flame retardant solution at a bath ratio of 1:5-1:50 and a temperature of 40-100 DEG C, then the fabric is treated by padding, the weight gain of the fabric after flame-retardant finishing is controlled by adjusting the liquid rate of the fabric, then the fabric is pre-dried at a temperature of 50-100 DEG C, and the fabric is cured at a high temperature of 120-200 DEG C by a setting machine. Specifically, the pre-drying time is 1-10 min, and the curing time is 1-5 min.

[0012] The fabric is a fabric that can be treated by pad baking technology, including but not limited to any one of cotton, polyester, polyester-cotton blended fabric, viscose, modal, lyocell, cotton-viscose blended fabric, nylon, wool, silk and the like.

[0013] The person skilled in the art can also add optional other auxiliary agents according to the needs to obtain better use performance, which can be selected from whitening agents, bactericides, antistatic agents, crosslinking agents, strength retention agents and the like, which can be added simultaneously or separately.

[0014] The phytic acid modified starch is obtained by a simple esterification reaction between a series of starches and phytic acid in a certain mass ratio, and then the flame retardant is finished on the surface of the fabric by pad baking technology. The starch, as a biomass polysaccharide, can esterify with the phosphate groups on the phytic acid through the hydroxyl groups contained therein, so as to alleviate the problem of low strength retention rate caused by the use of phytic acid, and achieve the coordination of the flame-retardant effect and the strength retention of the fabric. In the process, excess starch is used, and the excess starch after gelatinization can improve the viscosity of the phytic acid modified starch flame retardant solution, so as to be better loaded on the fabric and improve the washing resistance.

[0015] Compared with the prior art, the present application has the following beneficial effects: (1) the present application uses starch as raw material, which has the characteristics of renewable, wide source, diverse types, low price and easy availability; (2) the present application prepares phytic acid modified starch by esterification reaction of starch and phytic acid, which is simple to operate and easy to realize, and the reaction of the phosphoric acid group of starch and phytic acid reduces the acidity of phytic acid; (3) the present application controls the reaction temperature to ensure that the prepared phytic acid modified starch flame retardant can be effectively adhered to the fabric, and has a certain water washing resistance; (4) the prepared phytic acid modified starch is used for fabric flame retardant modification, when the fabric is heated, the flame retardant decomposes in advance and promotes the fabric to form a stable carbon layer, thereby insulating heat and oxygen, protecting the underlying fabric, and effectively improving the flame retardant performance of the fabric; (5) the crosslinking effect of the added flame retardant and the bonding effect of the starch can prevent the breakage caused by the slippage of the molecular chain of the fabric, so that the strength of the fabric can be preserved; (6) phytic acid, starch and water are all environmentally friendly raw materials, and the synthesized flame retardant is an environmentally friendly flame retardant, which reduces the consumption of petrochemical resources and reduces the environmental burden. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a strength test image of the flame-retardant fabric prepared by the flame retardant prepared in Example 1 after reaction with different mass ratios.

[0017] Figure 2 is a strength test image of the flame-retardant fabric prepared by the flame retardant prepared in Example 2 at different reaction temperatures.

[0018] Figure 3 is a residual carbon image of the flame-retardant fabric after vertical combustion test in Example 3, (a) is pure lyocell, (b) is flame-retardant lyocell 1, (c) is flame-retardant lyocell 2, (d) is flame-retardant lyocell 2 after 5 times of washing, and (e) is flame-retardant lyocell 2 after 20 times of washing. DETAILED DESCRIPTION

[0019] The present application will be further illustrated in conjunction with the specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present application and not to limit the scope of the present application. If some non-essential adjustments and improvements are made to the present application by those skilled in the art according to the content of the present application, they still belong to the protection scope of the present application.

[0020] Example 1:

[0021] A preparation method of a phytic acid modified starch flame retardant and its application in fabric flame retardation, the steps are:

[0022] (1) corn starch and phytic acid with different mass ratios are reacted at 130℃ for 3h to obtain a phytic acid modified starch flame retardant.

[0023] (2) Phytic acid modified starch flame retardant was dissolved in water to prepare 100 g / L flame retardant solution, then Lyocell fabric was treated by dip-dyeing and pad-drying in different flame retardant solutions with 1:20 bath ratio at 70℃, and then the fabric was pre-dried at 80℃ for 3 min, and cured at 170℃ for 3 min. The flame retardant properties and strength of the prepared flame retardant fabric were tested and compared, and the best phytic acid: starch mass ratio of 1:1 was selected. The specific experimental results are shown in Table 1 and Figure 1

[0024] Table 1. Flame retardant properties of samples after reaction with different mass ratios

[0025]

[0026] In addition to the above ratio, the mass ratio of phytic acid: starch can also be selected as 5:1, 4:1, 1:4, 1:5, etc., the bath ratio can also be adjusted in the range of 1:5-1:50, and the temperature of dip-dyeing and pad-drying can also be adjusted to 40℃, 50℃, 60℃, 80℃, 90℃, 100℃ according to actual needs, the pre-drying temperature can be adjusted to 50℃, 60℃, 70℃, 90℃ and 100℃, the curing temperature can be adjusted to 120℃, 130℃, 140℃, 150℃, 160℃, 180℃, 190℃, 200℃, and the starch can be selected from commonly used starches such as corn starch, sweet potato starch, potato starch, cassava starch, glutinous rice starch, chestnut starch, and green bean starch.

[0027] Example 2:

[0028] A preparation method of a phytic acid modified starch flame retardant and its application in fabric flame retardation, the steps are:

[0029] (1) Corn starch and phytic acid with a mass ratio of 1:1 were respectively reacted at 30℃, 50℃, 60℃, 80℃, 90℃, 130℃ and 150℃ for 3h.

[0030] ​(2) The phytic acid modified starch flame retardant was dissolved in water to obtain a 100 g / L flame retardant solution. Then, Lyocell fabric was treated by dip-dyeing and padding in the flame retardant solution at a bath ratio of 1:20 at 70°C, followed by pre-drying at 80°C for 3 min and curing at 170°C for 3 min. It was found that when the temperature was lower than 50°C, the phytic acid modified starch flame retardant prepared was easy to fall off the fabric, which might be due to the low temperature and the starch not reaching the gelatinization temperature, resulting in poor adhesion. As the temperature increased, the falling off phenomenon was significantly improved. When the temperature was higher than 80°C, the phytic acid modified starch had good adhesion on the fabric and basically did not fall off. In addition, as the reaction temperature increased, the esterification reaction proceeded more efficiently, and the strength retention rate of the fabric was higher. The flame retardant properties and strength of the prepared flame retardant fabric were tested, and the specific experimental results are shown in Table 2 and Figure 2

[0031] Table 2. Flame retardant properties of samples at different flame retardant reaction temperatures

[0032]

[0033]

[0034] Example 3

[0035] A method for preparing a phytic acid modified starch flame retardant and its application in fabric flame retardation, the steps are as follows:

[0036] (1) Corn starch and phytic acid with a mass ratio of 1:1 were reacted at 100°C for 3h to obtain a viscous phytic acid modified starch flame retardant.

[0037] (2) The phytic acid modified starch flame retardant was added to water using a spoon to prepare 100 g / L and 200 g / L flame retardant solutions (as shown in Table 3). Then, Lyocell fabric was treated by dip-dyeing and padding in the flame retardant solution at a bath ratio of 1:20 at 70°C, followed by pre-drying at 80°C for 3 min and curing at 170°C for 3 min to obtain flame retardant Lyocell 1 and flame retardant Lyocell 2. The flame retardant properties are shown in Table 3 and Figure 3 Figure 1 It can be understood that the strength of the Lyocell fabric treated with pure phytic acid was greatly damaged, while the strength retention of the Lyocell fabric treated with phytic acid modified starch reached 80%.

[0038] Table 3. Vertical burning and limiting oxygen test data of samples

[0039]

[0040] Comparative Example 1

[0041] ​​A preparation method of a phytic acid modified starch flame retardant and application thereof in fabric flame retardation, steps are as follows:

[0042] (1) corn starch, phytic acid and urea with a mass ratio of 2:2:1 are reacted at 100 DEG C for 3h to obtain a phytic acid modified starch flame retardant, compared with example 3, the viscosity of the prepared phytic acid modified starch flame retardant is reduced, and it can be directly poured out.

[0043] (2) the phytic acid modified starch flame retardant is directly poured into water to prepare a 200g / L flame retardant solution, then lyocell fabric is subjected to two-dip-two-nip finishing in different flame retardant solutions at a bath ratio of 1:20 and at 70 DEG C, and then the fabric is pre-dried at 80 DEG C for 3min and cured at 170 DEG C for 3min.

[0044] Comparative example 2:

[0045] A preparation method of a phytic acid modified starch flame retardant and application thereof in fabric flame retardation, steps are as follows:

[0046] (1) corn starch, phytic acid and boric acid with a mass ratio of 2:2:1 are reacted at 100 DEG C for 3h to obtain a phytic acid modified starch flame retardant, compared with example 3, the viscosity of the prepared phytic acid modified starch flame retardant is reduced, and it can be directly poured out.

[0047] (2) the phytic acid modified starch flame retardant is directly poured into water to prepare a 200g / L flame retardant solution, then lyocell fabric is subjected to two-dip-two-nip finishing in different flame retardant solutions at a bath ratio of 1:20 and at 80 DEG C, and then the fabric is pre-dried at 80 DEG C for 3min and cured at 170 DEG C for 3min.

[0048] Comparative example 3:

[0049] A preparation method of a phytic acid modified starch flame retardant and application thereof in fabric flame retardation, steps are as follows:

[0050] (1) corn starch, phytic acid, urea and boric acid with a mass ratio of 2:2:1:1 are reacted at 100 DEG C for 3h to obtain a phytic acid modified starch flame retardant, compared with example 3, the viscosity of the prepared phytic acid modified starch flame retardant is reduced, and it can be directly poured out.

[0051] (2) the phytic acid modified starch flame retardant is directly poured into water to prepare a 200g / L flame retardant solution, then lyocell fabric is subjected to two-dip-two-nip finishing in different flame retardant solutions at a bath ratio of 1:20 and at 70 DEG C, and then the fabric is pre-dried at 80 DEG C for 3min and cured at 170 DEG C for 3min.

[0052] The flame retardant fabrics obtained in comparative examples 1-3 and the three groups of flame retardant fabrics are respectively subjected to 5 times of water washing and 20 times of water washing, and vertical combustion experiments are conducted, and the specific results are shown in table 4:

[0053] Table 4. Sample Vertical Burning and Limiting Oxygen Index Test Data

[0054]

[0055] It is apparent that the addition of urea and boric acid macroscopically reduces the viscosity of the system and reduces the wash durability of the system. This can be due to the fact that the urea and boric acid affect the degree of pasting of the starch or react with the starch to reduce the amount of starch available to paste to provide durability.

[0056] Those skilled in the art should understand that the above description is only the specific embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A process for the production of a semi-durable flame resistant fabric, characterized in that, The steps are as follows: The starch and phytic acid are uniformly mixed, and an esterification reaction is carried out at 60-150 DEG C to obtain phytic acid modified starch, a phytic acid modified starch flame retardant solution is prepared, and the fabric is soaked in the flame retardant solution, and the flame retardant is finished on the fabric by using the pad-dry-cure technology.

2. The method of making a semi-durable flame resistant fabric of claim 1, wherein, The reaction temperature is 80-130 DEG C.

3. The method of making a semidurable flame resistant fabric of claim 1, wherein, The mass ratio of starch to phytic acid is 5:1-1:5, and the reaction time is 1-8 h.

4. The method of making a semidurable flame resistant fabric of claim 1, wherein, The starch is any one of corn starch, sweet potato starch, potato starch, cassava starch, glutinous rice starch, chestnut starch, and green bean starch.

5. The method of making a semidurable flame resistant fabric of claim 1, wherein, The fabric is soaked in the 40-500 g / L flame retardant solution at a bath ratio of 1:5-1:50 and a temperature of 40-100 DEG C, and then the fabric is subjected to padding treatment, the weight gain of the fabric after flame retardant finishing is controlled by controlling the liquid retention rate of the fabric, and then the fabric is pre-dried at a temperature of 50-100 DEG C, and the fabric is cured at a high temperature of 120-200 DEG C by using a setting machine.

6. The method of making a semidurable flame resistant fabric of claim 1, wherein, The pre-drying time is 1-10 min, and the curing time is 1-5 min.

7. The method of making a semidurable flame resistant fabric of claim 1, wherein, The fabric is a fabric that can be finished by using the pad-dry-cure technology.

Images