Hydroxypropyl cellulose solution with fiber reinforcement function as well as preparation method and application thereof

Abstract

The invention discloses a hydroxy propyl cellulose solution with a fiber reinforcing function and a preparation method and application thereof, and belongs to the field of hydroxy propyl cellulose preparation.The method comprises the steps that hydroxy propyl cellulose and 3-glycidyl ether oxypropyl trimethoxy silane are evenly mixed according to the mass ratio of 10: (1-5), then heating treatment is conducted, and the hydroxy propyl cellulose solution with the fiber reinforcing function is obtained; the powdery modified hydroxy propyl cellulose is obtained; and dissolving the modified hydroxy propyl cellulose in deionized water or an organic solvent to obtain a hydroxy propyl cellulose solution with a fiber reinforcement function. The preparation method is simple in process, easy to implement and low in cost, and hydroxy propyl cellulose is modified by using the silane coupling agent KH560, so that the binding power of the hydroxy propyl cellulose and the crosslinking strength of the hydroxy propyl cellulose and various plant fibers are enhanced, and the performance of the hydroxy propyl cellulose is stable.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of hydroxypropyl cellulose, and particularly relates to a hydroxypropyl cellulose solution with fiber reinforcement function, a preparation method and an application thereof. Background Art

[0002] Hydroxypropyl cellulose is considered to be one of the most promising cellulose derivatives. Due to advantages such as simple and low-cost synthesis process, good biocompatibility, degradability, edibility and thermoplasticity, it is widely used in various advanced fields, such as food, paper-making, textile and pharmaceutical industries, biomedical engineering, wastewater treatment, etc.

[0003] In order to develop hydroxypropyl cellulose with better performance and wider applicability, many scholars have done a lot of work in the modification of hydroxypropyl cellulose. Although certain effects have been achieved, there are still some problems. For example, grafting functional monomers or polymers (such as acrylic acid, acrylamide, polyethylene glycol), and introducing responsive groups for functional modification will make the reaction controllability poor, the structure inhomogeneous, and at the same time the characterization is difficult; through physical modification, blending or composite with nanomaterials, there are limitations in performance improvement, poor persistence, insufficient compatibility, sometimes there are certain defects at the interface, the nanoparticles are easy to agglomerate, and the stress is relatively concentrated.

[0004] Therefore, chemical modification methods have been gradually widely applied. For example, introducing cross-linking agents for cross-linking modification can accurately regulate the hydrophilicity-hydrophobicity and bioadhesion, environmental responsiveness of hydroxypropyl cellulose, improve biocompatibility and solvent resistance, and enhance mechanical properties. However, the improvement of performance is relatively easy to depend on cross-linking conditions, the processing difficulty increases, and there are problems of complex process and high cost. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a hydroxypropyl cellulose solution with fiber reinforcement function, a preparation method and an application thereof, which solves the problems that when chemically modifying hydroxypropyl cellulose currently, the performance improvement is relatively easy to depend on cross-linking conditions, the processing difficulty increases, the process is complex and the cost is high. The process is simple, easy to implement, and low in cost. The hydroxypropyl cellulose is modified with silane coupling agent KH560, so as to enhance the adhesion of hydroxypropyl cellulose and the cross-linking strength with various plant fibers, and make its performance stable.

[0006] The present invention is realized through the following technical solutions:

[0007] A preparation method of a hydroxypropyl cellulose solution with fiber reinforcement function, comprising the following steps:

[0008] S1. Mix hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly at a mass ratio of 10:(1 - 5), and then perform heat treatment to obtain powdery modified hydroxypropyl cellulose.

[0009] S2. Dissolve the modified hydroxypropyl cellulose in deionized water or an organic solvent to obtain a hydroxypropyl cellulose solution with fiber reinforcement function.

[0010] A further improvement of the present invention lies in:

[0011] In S1, first mix hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly at room temperature, and then perform heat treatment.

[0012] After mixing hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly in S1, perform heat treatment at 30 - 50 °C to obtain modified hydroxypropyl cellulose.

[0013] After mixing hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly in S1, heat at 30 - 50 °C for 1 - 5 h to obtain modified hydroxypropyl cellulose.

[0014] When S2 dissolves the modified hydroxypropyl cellulose in deionized water, the mass percentage of the modified hydroxypropyl cellulose in the hydroxypropyl cellulose solution is 1% - 5%.

[0015] A hydroxypropyl cellulose solution with fiber reinforcement function obtained by the preparation method of the hydroxypropyl cellulose solution with fiber reinforcement function described in any one of the above.

[0016] Application of the hydroxypropyl cellulose solution with fiber reinforcement function in enhancing the strength of paper.

[0017] Mix the hydroxypropyl cellulose solution with paper pulp, then perform beating, and finally form the paper to obtain paper sheets.

[0018] Dehydrate the paper sheets, and then perform hot pressing and drying in sequence to obtain the strengthened paper.

[0019] Hot press the dehydrated paper sheets at 80 - 90 °C for 5 - 8 min, and then dry at 45 - 55 °C for 4 - 6 h to obtain the strengthened paper.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] A preparation method of a hydroxypropyl cellulose solution with fiber-reinforcing function, using hydroxypropyl cellulose as the matrix, crosslinking and modifying it with silane coupling agent KH560 under heating conditions. The hydroxyl groups on the molecular chain of hydroxypropyl cellulose undergo ring-opening reaction of the epoxy group with the highly reactive epoxy propane in the KH560 molecule to form strong covalent bonds, thereby effectively improving its mechanical properties and thermal stability. The modified organic side chain of hydroxypropyl cellulose has certain flexibility and steric hindrance effect, which can increase the activity of the molecular chain, enabling KH560 to better adapt to and regulate the interaction between interfaces when binding to hydroxypropyl cellulose. The epoxy group, propyl chain and siloxane group in the KH560 molecule introduce hydrophobic groups through chemical bonding with hydroxypropyl cellulose, changing the force between molecular chains, increasing the molecular chain spacing, enhancing the flexibility and interfacial compatibility of the molecular chain, and significantly improving the solubility of hydroxypropyl cellulose, so that hydroxypropyl cellulose can be more easily dissolved in water or organic solvents. The raw materials used in the present invention are non-toxic and pollution-free, more suitable for industrial production. The obtained hydroxypropyl cellulose solution has the advantages of low viscosity, good fluidity, uniform film formation, and strong adhesion. It has a high crosslinking strength, stable performance, fast drying speed, convenient use and low cost when crosslinked with various plant fibers.

[0022] When the hydroxypropyl cellulose solution with fiber-reinforcing function is applied in enhancing the strength of paper in the present invention, the hydroxyl groups and ether bonds in the modified hydroxypropyl cellulose can form hydrogen bonds or van der Waals forces with the cellulose in the paper, thereby having strong adhesiveness, enabling it to bond different paper materials and enhancing the strength and tensile properties of the paper. Description of the Drawings

[0023] Figure 1 It is the infrared spectrum diagram of the modified fiber obtained in Example 1 of the present invention;

[0024] Figure 2 It is the TG curve diagram of the modified fiber obtained in Example 1 of the present invention;

[0025] Figure 3 It is the DSC curve diagram of the modified fiber obtained in Example 1 of the present invention;

[0026] Figure 4a It is the XPS curve diagram of element C in the modified fiber obtained in Example 1 of the present invention;

[0027] Figure 4b It is the XPS curve diagram of element O in the modified fiber obtained in Example 1 of the present invention;

[0028] Figure 5 It is the mechanical property test diagram of the modified fiber obtained in Example 1 of the present invention.

[0029] Figure 6This is the mechanical property test chart of the paper added with modified fibers obtained from Comparative Examples 1-3 and Example 1 of the present invention. Detailed implementation manners

[0030] The present invention will be described in detail below with reference to the embodiments. The description in this part is only exemplary and explanatory, and should not have any restrictive effect on the protection scope of the present invention.

[0031] Silane coupling agent is a commonly used surface modifier. Due to its special molecular structure, it can establish chemical bonds between inorganic substances and organic substances, thereby improving the adhesion and compatibility between fibers and matrix materials. And it has outstanding advantages such as low cost, easy operation, and good effect, and is widely used in surface treatment, filled plastics, and as a tackifier for sealants, adhesives, and coatings, etc.

[0032] Based on this, the present invention discloses a preparation method of a hydroxypropyl cellulose solution with fiber reinforcement function, which is obtained by modifying hydroxypropyl cellulose with silane coupling agent 3-glycidoxypropyltrimethoxysilane (KH-560), and specifically includes the following steps:

[0033] Step 1: Preparation of modified hydroxypropyl cellulose

[0034] Mix KH-560 and hydroxypropyl cellulose in a mass ratio of (1-5):10, fully mix and stir evenly at room temperature, and place it in an oven at a temperature of 30°C - 50°C for 1h - 5h to obtain powdery modified hydroxypropyl cellulose.

[0035] Step 2: Preparation of modified hydroxypropyl cellulose solution

[0036] Under room temperature conditions, dissolve the cellulose in Step 1 with deionized water to prepare a hydroxypropyl cellulose solution with fiber reinforcement function with a mass percentage of 1-5%.

[0037] The hydroxypropyl cellulose solution with fiber reinforcement function of the present invention can continue to be applied in enhancing the strength of paper, and specifically includes the following steps:

[0038] Step 3: Mix the hydroxypropyl cellulose solution with fiber reinforcement function with the pulp, and perform beating in a beater (6000 revolutions per minute), and then use a paper former to make samples;

[0039] Step 4: Dehydrate the obtained paper sheets with a press, then use a flat vulcanizing machine to hot press the paper sheets at 80-90°C for 5-8 minutes, transfer the paper sheets to an oven at 45-55°C to dry for 4-6 hours, and then obtain paper specimens.

[0040] Example 1

[0041] Mix KH-560 and hydroxypropyl cellulose (HPC) in a mass ratio of 1:10, and mix and stir well at room temperature, then place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% mass percentage solution.

[0042] Perform infrared testing on the modified hydroxypropyl cellulose powder to obtain Figure 1 The infrared spectrum shown. It can be seen that the disappearance of the epoxy group peak and the formation of Si-O-Si or Si-O-C bonds indicate that KH560 has successfully reacted with HPC. Secondly, the weakening of the O-H peak intensity indicates that the epoxy group of KH560 has reacted with the hydroxyl group of HPC. And a new peak appears at 1600 cm-1, which is due to the formation of carboxylate (COO-) or C=C double bonds during the reaction, or a part of the water remains in the sample.

[0043] Perform thermal analysis testing on the modified hydroxypropyl cellulose powder to obtain Figure 2 The TG curve shown in the figure. It can be seen that the TG curve in the figure shows an initial weight loss at about 100 °C, mainly due to the volatilization of adsorbed water and solvents in the modified sample. And the decomposition temperature of the modified sample increases to 320 °C, indicating that the modification of KH560 improves the thermal stability of the sample. In addition, it can be seen from the DTG curve that the peak temperature of the DTG of the modified sample increases and the peak shape becomes sharper, indicating that the modified sample has a more single thermal decomposition mechanism.

[0044] Perform DSC testing on the modified hydroxypropyl cellulose powder to obtain Figure 3 The DSC curve shown in the figure. It can be seen that the exothermic peak that appears at 120-150 °C is the result of the ring-opening reaction of the epoxy group of KH560 and the hydroxyl group of HPC. In addition, the baseline shifts towards the high temperature direction, indicating that the thermal stability of the modified hydroxypropyl cellulose has been improved.

[0045] Perform X-ray photoelectron spectroscopy testing on the modified hydroxypropyl cellulose powder to obtain Figure 4a and Figure 4b The XPS curves shown in the figure. It can be seen that the appearance of Si-C, Si-O and Si-O-Si peaks indicates that the siloxane groups of KH560 have reacted with HPC or itself.

[0046] Cast the modified cellulose solution into a film using a polytetrafluoroethylene plate and dry it in a vacuum oven at 50 °C. Then perform tensile property testing to obtain Figure 5 The tensile property test diagram shown in the figure. It can be seen that both the tensile strength and the elongation at break of the film have increased, indicating that KH560 has improved the mechanical properties of hydroxypropyl cellulose.

[0047] Comparative Example 1

[0048] Mix KH-570 and hydroxypropyl cellulose in a mass ratio of 5:10, and under room temperature conditions, mix and stir well. Place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% by mass solution.

[0049] Comparative Example 2

[0050] Mix KH-550 and hydroxypropyl cellulose in a mass ratio of 5:10, and under room temperature conditions, mix and stir well. Place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% by mass solution.

[0051] Comparative Example 3

[0052] Mix KH-540 and hydroxypropyl cellulose in a mass ratio of 5:10, and under room temperature conditions, mix and stir well. Place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% by mass solution.

[0053] Add the above modified cellulose solution into the pulp in an amount of 3% during paper making, and conduct a tensile property test on the made paper to obtain Figure 6 the stress-strain diagram. It can be seen from the figure that the hydroxypropyl cellulose modified by KH560 has the most obvious strengthening effect on the paper. The stress can reach 38.76 MPa and the strain is 3.27%. Therefore, KH560 is used to modify hydroxypropyl cellulose.

[0054] Example 2

[0055] Mix KH-560 and hydroxypropyl cellulose in a mass ratio of 2:10, and under room temperature conditions, mix and stir well. Place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% by mass solution.

[0056] Example 3

[0057] Mix KH-560 and hydroxypropyl cellulose in a mass ratio of 3:10, and under room temperature conditions, mix and stir well. Place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% by mass solution.

[0058] Example 4

[0059] Mix KH-560 and hydroxypropyl cellulose in a mass ratio of 4:10, and under room temperature conditions, mix and stir well. Place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% (mass percentage) solution.

[0060] Example 5

[0061] Mix KH-560 and hydroxypropyl cellulose in a mass ratio of 5:10, and under room temperature conditions, mix and stir well. Place it in an oven at 50 °C for 5 h. Under room temperature conditions, dissolve the modified cellulose with deionized water to prepare a 1% (mass percentage) solution.

Claims

1. A preparation method of a hydroxypropyl cellulose solution with fiber reinforcement function, characterized in that, It includes the following steps: S1. Mix hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly at a mass ratio of 10:(1 - 5), and then heat-treat to obtain modified hydroxypropyl cellulose; S2. Dissolve the modified hydroxypropyl cellulose in deionized water or an organic solvent to obtain a hydroxypropyl cellulose solution with fiber-reinforcing function.

2. The preparation method of the hydroxypropyl cellulose solution with fiber reinforcement function according to claim 1, characterized in that, In S1, first mix hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly at room temperature, and then heat-treat.

3. The preparation method of the hydroxypropyl cellulose solution with fiber reinforcement function according to claim 2, characterized in that, After mixing hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly in S1, heat-treat at 30 - 50 °C to obtain modified hydroxypropyl cellulose.

4. The preparation method of the hydroxypropyl cellulose solution with fiber reinforcement function according to claim 3, characterized in that, After mixing hydroxypropyl cellulose and 3-glycidoxypropyltrimethoxysilane evenly in S1, heat at 30 - 50 °C for 1 - 5 h to obtain modified hydroxypropyl cellulose.

5. The preparation method of the hydroxypropyl cellulose solution with fiber reinforcement function according to claim 1, characterized in that, The modified hydroxypropyl cellulose described in S1 is in powder form.

6. The preparation method of the hydroxypropyl cellulose solution with fiber reinforcement function according to claim 2, characterized in that, When the modified hydroxypropyl cellulose is dissolved in deionized water in S2, the mass percentage of the modified hydroxypropyl cellulose in the hydroxypropyl cellulose solution is 1% - 5%.

7. A hydroxypropyl cellulose solution with fiber-reinforcing function obtained by the preparation method of the hydroxypropyl cellulose solution with fiber-reinforcing function described in any one of claims 1 - 6.

8. Application of the hydroxypropyl cellulose solution with fiber-reinforcing function as described in claim 7 in enhancing the strength of paper.

9. Use of the hydroxypropyl cellulose solution with fiber reinforcement function according to claim 8 in enhancing the strength of paper, characterized in that, Mix the hydroxypropyl cellulose solution with paper pulp, then defibrate, and finally form the paper to obtain paper sheets; Dehydrate the paper sheets, and then hot-press and dry them in sequence to obtain the strengthened paper.

10. Use of the hydroxypropyl cellulose solution with fiber strengthening function according to claim 9 in strengthening the strength of paper, characterized in that, Hot-press the dehydrated paper sheets at 80 - 90 °C for 5 - 8 min, and then dry them at 45 - 55 °C for 4 - 6 h to obtain the strengthened paper.

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