阅读说明：本技术 一种高强度疏水型无纺布及其制备方法 (High-strength hydrophobic non-woven fabric and preparation method thereof ) 是由 廖国庆 于 2020-06-08 设计创作，主要内容包括：本发明涉及非织造布技术领域,公开了一种高强度疏水型无纺布及其制备方法,该无纺布包括以下重量份的原料：100份纤维素纤维,5～10份三羟甲基氨基甲烷-丙烯酸甲酯-双季戊四醇共聚物,30～35份1,6-二(丙烯酰氧基)-2,2,3,3,4,4,5,5-八氟己烷,2～2.5份季戊四醇四丙烯酸酯。本发明通过在无纺布内部加入三羟甲基氨基甲烷-丙烯酸甲酯-双季戊四醇共聚物,提高了无纺布的强度；通过在无纺布表面接枝1,6-二(丙烯酰氧基)-2,2,3,3,4,4,5,5-八氟己烷和季戊四醇四丙烯酸酯,提高了无纺布的强度和疏水性。(The invention relates to the technical field of non-woven fabrics, and discloses a high-strength hydrophobic non-woven fabric and a preparation method thereof, wherein the non-woven fabric comprises the following raw materials in parts by weight: 100 parts of cellulose fiber, 5-10 parts of trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer, 30-35 parts of 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and 2-2.5 parts of pentaerythritol tetraacrylate. According to the invention, the strength of the non-woven fabric is improved by adding the trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer into the non-woven fabric; the strength and the hydrophobicity of the non-woven fabric are improved by grafting 1, 6-di (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate on the surface of the non-woven fabric.)

1. The high-strength hydrophobic non-woven fabric is characterized by comprising the following raw materials in parts by weight: 100 parts of cellulose fiber, 5-10 parts of trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer, 30-35 parts of 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and 2-2.5 parts of pentaerythritol tetraacrylate.

2. The high-strength hydrophobic nonwoven fabric according to claim 1, wherein the method for preparing the tris-hydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer is as follows:

(i) addition reaction: adding trihydroxymethyl aminomethane into a methanol water solution, heating to 30-35 ℃, and stirring for dissolving; dropwise adding a methanol solution of methyl acrylate, and reacting for 2-3 h at the temperature of 30-35 ℃; after the reaction is finished, vacuumizing to remove methanol, water and excessive methyl acrylate to obtain an addition reaction product;

(ii) ester exchange reaction: adding dipentaerythritol into dimethyl sulfoxide, heating to 90-100 ℃, and stirring for dissolving; dropwise adding the addition reaction product obtained in the step (i), heating to 125-130 ℃, reacting for 2-3 h, and reacting for 1.5-2.5 h at 100-110 ℃ and 0.05-0.08 MPa; and after the reaction is finished, performing reduced pressure rotary evaporation to remove dimethyl sulfoxide to obtain the trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer.

3. The high-strength hydrophobic nonwoven fabric according to claim 2, wherein in the step (i), the mass ratio of the tris to the methyl acrylate is 1:1 to 1.5.

4. The high-strength hydrophobic nonwoven fabric according to claim 2, wherein the mass ratio of dipentaerythritol in step (ii) to tris in step (i) is 1:3.5 to 4.

5. The high-strength hydrophobic nonwoven fabric according to claim 1 or 2, wherein the tris-hydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer is a terpolymer modified by carboxyl grafting in the following way:

(a) ring opening reaction: dissolving a trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer in N, N-dimethylformamide, adding a ring-opening reaction catalyst, dropwise adding an N, N-dimethylformamide solution of 2-oxaproyl ethyl acetate, and reacting for 2-3 h at the temperature of 70-80 ℃; after the reaction is finished, carrying out reduced pressure distillation to remove the N, N-dimethylformamide and obtain a ring-opening reaction product;

(b) and (3) hydrolysis reaction: dissolving the ring-opening reaction product obtained in the step (a) in water, adding a sodium hydroxide solution, and reacting at 60-70 ℃ for 1-2 h; after the reaction is finished, the water is removed by reduced pressure distillation, and the terpolymer modified by carboxyl grafting is obtained.

6. The high-strength hydrophobic nonwoven fabric according to claim 5, wherein in the step (a), the mass ratio of the trihydroxymethylaminomethane-methyl acrylate-dipentaerythritol copolymer to the 2-oxaproyl ethyl acetate is 1: 1.5-2.

7. A method for preparing the high-strength hydrophobic nonwoven fabric as claimed in any one of claims 1 to 4, comprising the steps of:

(1) loosening cellulose fibers, and dispersing the loosened cellulose fibers in water to prepare a fiber suspension;

(2) mixing the fiber suspension with a trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer, and performing wet-laid to prepare a fiber web;

(3) carrying out spunlace reinforcement, washing and drying on the fiber web to obtain a spunlace fiber web;

(4) 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate are taken as grafting monomers, and ultraviolet surface grafting is carried out on the spunlace fiber web to obtain a fiber web subjected to grafting treatment;

(5) and cutting the grafted fiber web to obtain the high-strength hydrophobic non-woven fabric.

8. The method for preparing a high-strength hydrophobic nonwoven fabric according to claim 7, wherein in the step (4), the ultraviolet surface grafting method comprises the following steps: dissolving 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane, pentaerythritol tetraacrylate and a photoinitiator in acetone to prepare a mixed solution; immersing the spunlace fiber web into the mixed solution, and carrying out grafting reaction under ultraviolet light; after the reaction, the spunlace fiber web is transferred into acetone, monomers and polymers which are not grafted to the spunlace fiber web are removed through ultrasonic treatment, and the monomers and polymers which are not grafted to the spunlace fiber web are further removed through acetone extraction.

9. A method for preparing the high-strength hydrophobic nonwoven fabric as claimed in any one of claims 5 to 6, comprising the steps of:

(1) loosening cellulose fibers, and dispersing the loosened cellulose fibers in water to prepare a fiber suspension;

(2) adding an esterification reaction catalyst into the fiber suspension, dropwise adding an aqueous solution of a carboxyl graft modified terpolymer under stirring, and reacting for 2-3 h at 80-85 ℃; after the reaction is finished, wet-laying to prepare a fiber web;

(3) carrying out spunlace reinforcement, washing and drying on the fiber web to obtain a spunlace fiber web;

(4) 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate are taken as grafting monomers, and ultraviolet surface grafting is carried out on the spunlace fiber web to obtain a fiber web subjected to grafting treatment;

(5) and cutting the grafted fiber web to obtain the high-strength hydrophobic non-woven fabric.

10. The method for preparing the high-strength hydrophobic nonwoven fabric according to claim 9, wherein in the step (4), the ultraviolet surface grafting method comprises the following steps: dissolving 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane, pentaerythritol tetraacrylate and a photoinitiator in acetone to prepare a mixed solution; immersing the spunlace fiber web into the mixed solution, and carrying out grafting reaction under ultraviolet light; after the reaction, the spunlace fiber web is transferred into acetone, monomers and polymers which are not grafted to the spunlace fiber web are removed through ultrasonic treatment, and the monomers and polymers which are not grafted to the spunlace fiber web are further removed through acetone extraction.

Technical Field

The invention relates to the technical field of non-woven fabrics, in particular to a high-strength hydrophobic non-woven fabric and a preparation method thereof.

Background

Nonwoven fabrics, also known as nonwovens, are sheets, webs, or batts made of oriented or randomly arranged fibers that are bonded to one another by abrasion, cohesion, or bonding, or a combination of these methods. Due to the characteristics of wide raw materials, short production flow, low cost and the like, the non-woven fabric is widely applied to the fields of civil textiles and industrial textiles. Among various raw materials for producing nonwoven fabrics, cellulose-based nonwoven fabrics have unique applications in medical, nursing, hygienic, cosmetic and other industrial fields because cellulose fibers have properties that cannot be possessed by a series of synthetic fibers, such as easy manageability and easy biodegradability. However, cellulose-based nonwoven fabrics cannot be used in applications requiring water repellency due to their high water absorption.

At present, the hydrophobic modification method for cellulose fiber fabric mostly focuses on water and oil repellent finishing of the fabric by using nano materials, namely, a proper super-hydrophobic nano particle special function mother solution is adopted to carry out padding treatment and sizing treatment on the fiber surface, the nano particles are highly dispersed among yarns, among fibers and on the fiber surface through the combination of the adhesive and the fibers, the nano particles and the adhesive are in concave-convex arrangement on the fiber surface, and a nano-sized air film is formed in a nano-sized groove, so that the hydrophobicity of the fabric surface is improved. However, the hydrophobic fabric obtained by this method has poor durability, and the nanoparticles are not firmly bonded to the fabric, and easily fall off to affect the hydrophobicity of the fabric.

Disclosure of Invention

In order to solve the technical problems, the invention provides a high-strength hydrophobic non-woven fabric and a preparation method thereof. The non-woven fabric has good hydrophobicity, and the hydrophobic interface is firmly combined with the non-woven fabric, so that the non-woven fabric has good durability; in addition, the non-woven fabric has high strength, is durable and is not easy to damage.

The specific technical scheme of the invention is as follows:

a high-strength hydrophobic non-woven fabric comprises the following raw materials in parts by weight: 100 parts of cellulose fiber, 5-10 parts of trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer, 30-35 parts of 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and 2-2.5 parts of pentaerythritol tetraacrylate.

A method for preparing the high-strength hydrophobic non-woven fabric comprises the following steps:

(1) loosening cellulose fibers, and dispersing the loosened cellulose fibers in water to prepare a fiber suspension;

(2) mixing the fiber suspension with a trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer, and performing wet-laid to prepare a fiber web;

(3) carrying out spunlace reinforcement, washing and drying on the fiber web to obtain a spunlace fiber web;

(4) 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate are taken as grafting monomers, and ultraviolet surface grafting is carried out on the spunlace fiber web to obtain a fiber web subjected to grafting treatment;

(5) and cutting the grafted fiber web to obtain the high-strength hydrophobic non-woven fabric.

In the invention, the trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer and the cellulose fiber are blended and exist in the non-woven fabric, and the strength of the non-woven fabric is enhanced, and the mechanism is as follows: the trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer has a large number of terminal hydroxyl groups, and can form hydrogen bonds with free hydroxyl groups in cellulose fibers, so that more hydrogen bonds exist in a crosslinking area of the cellulose fibers, the crosslinking degree of the fibers is improved, and the strength of the non-woven fabric is increased; meanwhile, the terpolymer molecules have higher branching degree and can be crosslinked with cellulose fibers in all directions, so that the crosslinking degree of the fibers can be further improved, and the strength of the non-woven fabric is increased.

Since there are few hydroxyl groups liberated from cellulose fibers in the process of manufacturing a nonwoven fabric, the strength of the nonwoven fabric is improved to a limited extent by the tris/hydroxymethyl aminomethane/methylacrylate/dipentaerythritol copolymer. According to the invention, 1, 6-di (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate are grafted on the surface of the non-woven fabric, so that the strength of the non-woven fabric is further increased, and meanwhile, the non-woven fabric can obtain hydrophobicity, and the mechanism is as follows: the two grafting monomers are grafted to the surface of the spunlace fiber web through carbon-carbon double bonds; meanwhile, a plurality of carbon-carbon double bonds exist in the two grafting monomers, and the carbon-carbon double bonds can generate photoinitiated polymerization reaction, so that a cross-linked network-shaped structure is formed on the surface of the spunlace fiber web, and the strength of the non-woven fabric is increased; meanwhile, the fluorine-containing group in the 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane has better hydrophobicity, can form a hydrophobic interface on the surface of the non-woven fabric, and is not easy to fall off and has better durability because the hydrophobic interface is grafted on the surface of the non-woven fabric through a covalent bond.

Preferably, the tris-hydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer is a terpolymer modified by carboxyl grafting, and the modification method is as follows:

(a) ring opening reaction: dissolving a trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer in N, N-dimethylformamide, adding a ring-opening reaction catalyst, dropwise adding an N, N-dimethylformamide solution of 2-oxaproyl ethyl acetate, and reacting for 2-3 h at the temperature of 70-80 ℃; after the reaction is finished, carrying out reduced pressure distillation to remove the N, N-dimethylformamide and obtain a ring-opening reaction product;

(b) and (3) hydrolysis reaction: dissolving the ring-opening reaction product obtained in the step (a) in water, adding a sodium hydroxide solution, and reacting at 60-70 ℃ for 1-2 h; after the reaction is finished, the water is removed by reduced pressure distillation, and the terpolymer modified by carboxyl grafting is obtained.

A method for preparing the high-strength hydrophobic non-woven fabric comprises the following steps:

(1) loosening cellulose fibers, and dispersing the loosened cellulose fibers in water to prepare a fiber suspension;

(2) adding an esterification reaction catalyst into the fiber suspension, dropwise adding an aqueous solution of a carboxyl graft modified terpolymer under stirring, and reacting for 2-3 h at 80-85 ℃; after the reaction is finished, wet-laying to prepare a fiber web;

(3) carrying out spunlace reinforcement, washing and drying on the fiber web to obtain a spunlace fiber web;

(4) 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate are taken as grafting monomers, and ultraviolet surface grafting is carried out on the spunlace fiber web to obtain a fiber web subjected to grafting treatment;

(5) and cutting the grafted fiber web to obtain the high-strength hydrophobic non-woven fabric.

The trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer is grafted with carboxyl by modification, the carboxyl is subjected to esterification reaction with hydroxyl in cellulose fiber in the step (2), covalent crosslinking is formed between the terpolymer and the cellulose fiber, and compared with hydrogen bonds, the covalent crosslinking has larger bond energy, so that the strength of the non-woven fabric can be further improved.

Preferably, the method for preparing the tris-hydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer is as follows:

(i) addition reaction: adding trihydroxymethyl aminomethane into a methanol water solution, heating to 30-35 ℃, and stirring for dissolving; dropwise adding a methanol solution of methyl acrylate, and reacting for 2-3 h at the temperature of 30-35 ℃; after the reaction is finished, vacuumizing to remove methanol, water and excessive methyl acrylate to obtain an addition reaction product;

(ii) ester exchange reaction: adding dipentaerythritol into dimethyl sulfoxide, heating to 90-100 ℃, and stirring for dissolving; dropwise adding the addition reaction product obtained in the step (i), heating to 125-130 ℃, reacting for 2-3 h, and reacting for 1.5-2.5 h at 100-110 ℃ and 0.05-0.08 MPa; and after the reaction is finished, performing reduced pressure rotary evaporation to remove dimethyl sulfoxide to obtain the trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer.

In the step (i), amino in the trihydroxymethyl aminomethane and carbon-carbon double bond in the methyl acrylate are subjected to addition reaction; in the step (ii), the hydroxyl groups in the addition reaction product and the dipentaerythritol undergo transesterification with the ester groups in the addition reaction product, thereby obtaining the copolymer. The terpolymer prepared by the method contains a large number of terminal hydroxyl groups, has higher branching degree, and can effectively improve the strength of the non-woven fabric.

Preferably, in the step (i), the mass ratio of the tris (hydroxymethyl) aminomethane to the methyl acrylate is 1:1 to 1.5.

Preferably, the mass ratio of dipentaerythritol in step (ii) to tris (hydroxymethyl) aminomethane in step (i) is 1:3.5 to 4.

Preferably, in the step (a), the mass ratio of the tris-hydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer to the 2-oxaproyl ethyl acetate is 1: 1.5-2.

Preferably, in the step (a), the ring-opening reaction catalyst is at least one of a tertiary amine and a quaternary ammonium salt.

Preferably, in the step (4), the method of ultraviolet surface grafting is as follows: dissolving 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane, pentaerythritol tetraacrylate and a photoinitiator in acetone to prepare a mixed solution; immersing the spunlace fiber web into the mixed solution, and carrying out grafting reaction under ultraviolet light; after the reaction, the spunlace fiber web is transferred into acetone, monomers and polymers which are not grafted to the spunlace fiber web are removed through ultrasonic treatment, and the monomers and polymers which are not grafted to the spunlace fiber web are further removed through acetone extraction.

Under the irradiation of ultraviolet light, hydrogen on the surface of the cellulose is abstracted by a photoinitiator, so that free radicals are generated on the surface of the cellulose, and are combined with carbon-carbon double bonds in the grafting monomer 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate, thereby initiating the grafting reaction and the polymerization reaction of the grafting monomer on the surface of the cellulose.

Preferably, the mass fraction of the 1, 6-bis (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane in acetone is 40% to 50%.

Preferably, the photoinitiator is benzophenone; the mass fraction of the photoinitiator in acetone is 4.5-5%.

Compared with the prior art, the invention has the following advantages:

(1) the strength of the non-woven fabric can be improved by adding the trihydroxymethyl aminomethane-methyl acrylate-dipentaerythritol copolymer into the non-woven fabric;

(2) the strength of the non-woven fabric can be further improved by grafting a cross-linked network formed by 1, 6-di (acryloyloxy) -2,2,3,3,4,4,5, 5-octafluorohexane and pentaerythritol tetraacrylate on the surface of the non-woven fabric, and the non-woven fabric is endowed with a hydrophobic surface which has better durability.

Detailed Description

The present invention will be further described with reference to the following examples.