阅读说明：本技术 一种改性植物纤维和含改性植物纤维的耐磨餐具 (Modified plant fiber and wear-resistant tableware containing same ) 是由 刘海林 崔巍 赵原 刘和文 于 2020-05-07 设计创作，主要内容包括：本发明公开了一种改性植物纤维和含改性植物纤维的耐磨餐具,其中,改性植物纤维的制备方法如下：S1、对植物纤维进行碱处理,得到预处理植物纤维；S2、用改性聚四氟乙烯乳液对预处理植物纤维进行改性处理,得到植物纤维复合材料；S3、进行聚多巴胺包覆改性,得到改性植物纤维。本发明制得的改性植物纤维具有高强度和优良的耐磨性能,以其为填充料制成的餐具具有优良的耐磨性以及机械性能,色牢度高,不易褪色,耐用性强。(The invention discloses modified plant fibers and wear-resistant tableware containing the same, wherein the preparation method of the modified plant fibers comprises the following steps: s1, carrying out alkali treatment on the plant fiber to obtain pretreated plant fiber; s2, modifying the pretreated plant fibers by using the modified polytetrafluoroethylene emulsion to obtain a plant fiber composite material; and S3, carrying out polydopamine coating modification to obtain the modified plant fiber. The modified plant fiber prepared by the invention has high strength and excellent wear resistance, and tableware prepared by taking the modified plant fiber as a filler has excellent wear resistance and mechanical property, high color fastness, difficult fading and strong durability.)

1. The modified plant fiber is characterized by being prepared by the following steps:

s1, carrying out alkali treatment on the plant fiber to obtain pretreated plant fiber;

s2, modifying the pretreated plant fibers by using the modified polytetrafluoroethylene emulsion to obtain a plant fiber composite material;

and S3, carrying out polydopamine coating modification to obtain the modified plant fiber.

2. The modified plant fiber according to claim 1, which is prepared by the following method:

s1, carrying out alkali treatment on the plant fiber to obtain pretreated plant fiber;

s2, uniformly spraying the modified polytetrafluoroethylene emulsion into the pretreated plant fiber, and drying to obtain the plant fiber composite material, wherein the modified polytetrafluoroethylene emulsion is prepared by mixing polytetrafluoroethylene emulsion, nano titanium dioxide and potassium titanate whiskers;

s3, dipping the plant fiber composite material obtained in the step S2 in a dopamine hydrochloride solution, washing and drying to obtain the modified plant fiber.

3. The modified plant fiber as claimed in claim 2, wherein in step S1, the alkali treatment is performed by: soaking the plant fiber in 5-8% sodium hydroxide solution at 40-60 deg.C for 5-10 hr, washing, and drying to obtain pretreated plant fiber.

4. The modified plant fiber according to claim 2 or 3, wherein the modified polytetrafluoroethylene emulsion comprises polytetrafluoroethylene emulsion, nano titanium dioxide and potassium titanate whisker in a weight ratio of 1: (0.05-0.1): (0.03-0.05), the solid content of the polytetrafluoroethylene emulsion is 20-30%, the particle size of the nano titanium dioxide is 30-100nm, the diameter of the potassium titanate whisker is 0.1-0.6 μm, the length of the potassium titanate whisker is 3-20 μm, and the weight ratio of the modified polytetrafluoroethylene emulsion to the pretreated plant fiber is 1: (10-20).

5. The modified plant fiber according to any one of claims 2 to 4, wherein the concentration of the dopamine hydrochloride solution is 2 to 5g/L, and the weight ratio of the plant fiber composite material to the dopamine hydrochloride solution is (0.2 to 0.3): 1.

6. the modified plant fiber according to any one of claims 2 to 5, wherein the impregnation treatment in step S3 is carried out at a temperature of 25 to 30 ℃ for 12 to 24 hours.

7. The wear-resistant tableware containing the modified plant fiber is characterized by comprising the following raw materials in parts by weight:

60-80 parts of melamine formaldehyde resin, 5-10 parts of titanium dioxide, 50-70 parts of modified plant fiber according to any one of claims 1-6, 1-2 parts of microcrystalline cellulose, 0.5-1 part of phthalic anhydride, 0.3-0.5 part of polyamide wax, 0.3-0.5 part of antioxidant and 0.01-0.5 part of colorant.

8. The method for preparing the wear-resistant tableware containing modified plant fiber according to claim 7, comprising the following steps:

s1, weighing the raw materials according to the weight, mixing and stirring the melamine-formaldehyde resin, the titanium dioxide, the modified plant fiber, the microcrystalline cellulose, the polyamide wax, the antioxidant and the colorant uniformly, and then drying until the water content is less than or equal to 10%;

s2, mixing the material obtained in the step S1 with phthalic anhydride, and then ball-milling for 6-10 h;

s3, pouring the material obtained in the step S2 into a mould, heating and pressing for molding to obtain the wear-resistant tableware containing the modified plant fibers.

9. The method as claimed in claim 8, wherein the step S2, the temperature of the heating and pressing is 155-165 ℃, the pressure is 30-40MPa, and the time is 60-150S.

Technical Field

The invention relates to the technical field of composite materials, in particular to modified plant fibers and wear-resistant tableware containing the modified plant fibers.

Background

Melamine tableware, also known as porcelain-like tableware, is made by mixing melamine resin powder with plant fibers, inorganic fillers and other raw materials, heating, pressurizing and pressing to form. Because melamine tableware has the properties of lightness, attractive appearance, low temperature resistance, difficult breakage and the like, the melamine tableware is used in catering industry, children's catering industry and the like and is deeply loved by consumers. In recent years, along with the improvement of living standard of people, the performance requirement of melamine kitchen ware is gradually improved. Although the traditional melamine kitchen ware has the advantages of portability, wide temperature resistance range and the like, the wear resistance of the traditional melamine kitchen ware is deficient, the durability is not favorably improved, and the appearance quality is influenced due to the phenomenon of abrasion and discoloration possibly caused by long-term use. Therefore, the melamine resin composite material with high wear resistance is developed, and has very important practical significance for the field of melamine kitchenware.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides modified plant fiber and wear-resistant tableware containing the modified plant fiber.

The invention provides a modified plant fiber, which is prepared by the following steps:

s1, carrying out alkali treatment on the plant fiber to obtain pretreated plant fiber;

s2, modifying the pretreated plant fibers by using the modified polytetrafluoroethylene emulsion to obtain a plant fiber composite material;

and S3, carrying out polydopamine coating modification to obtain the modified plant fiber.

Preferably, the preparation method of the modified plant fiber comprises the following steps:

s1, carrying out alkali treatment on the plant fiber to obtain pretreated plant fiber;

s2, uniformly spraying the modified polytetrafluoroethylene emulsion into the pretreated plant fiber, and drying to obtain the plant fiber composite material, wherein the modified polytetrafluoroethylene emulsion is prepared by mixing polytetrafluoroethylene emulsion, nano titanium dioxide and potassium titanate whiskers;

s3, dipping the plant fiber composite material obtained in the step S2 in a dopamine hydrochloride solution, washing and drying to obtain the modified plant fiber.

Preferably, in step S1, the alkali treatment specifically includes: soaking the plant fiber in 5-8% sodium hydroxide solution at 40-60 deg.C for 5-10 hr, washing, and drying to obtain pretreated plant fiber.

Preferably, the plant fiber is one or a mixture of cotton fiber, hemp fiber, wood fiber and bamboo fiber.

Preferably, the weight ratio of the plant fiber to the sodium hydroxide solution is 1: (5-10).

Preferably, in the modified polytetrafluoroethylene emulsion, the weight ratio of the polytetrafluoroethylene emulsion to the nano titanium dioxide to the potassium titanate whisker is 1: (0.05-0.1): (0.03-0.05), the solid content of the polytetrafluoroethylene emulsion is 20-30%, the particle size of the nano titanium dioxide is 30-100nm, the diameter of the potassium titanate whisker is 0.1-0.6 μm, the length of the potassium titanate whisker is 3-20 μm, and the weight ratio of the modified polytetrafluoroethylene emulsion to the pretreated plant fiber is 1: (10-20).

Preferably, the concentration of the dopamine hydrochloride solution is 2-5g/L, and the dopamine hydrochloride solution is prepared by dissolving dopamine hydrochloride in a Tris-HCl solution with the pH value of 8.5; the weight ratio of the plant fiber composite material to the dopamine hydrochloride solution is (0.2-0.3): 1.

preferably, in the step S3, the temperature of the dipping treatment is 25-30 ℃ and the time is 12-24 h.

The wear-resistant tableware containing the modified plant fiber comprises the following raw materials in parts by weight:

60-80 parts of melamine formaldehyde resin, 5-10 parts of titanium dioxide, 50-70 parts of modified plant fiber, 1-2 parts of microcrystalline cellulose, 0.5-1 part of phthalic anhydride, 0.3-0.5 part of polyamide wax, 0.3-0.5 part of antioxidant and 0.01-0.5 part of colorant.

Preferably, the preparation method of the wear-resistant tableware containing the modified plant fiber comprises the following steps:

s1, weighing the raw materials according to the weight, mixing and stirring the melamine-formaldehyde resin, the titanium dioxide, the modified plant fiber, the microcrystalline cellulose, the polyamide wax, the antioxidant and the colorant uniformly, and then drying until the water content is less than or equal to 10%;

s2, mixing the material obtained in the step S1 with phthalic anhydride, and then ball-milling for 6-10 h;

s3, pouring the material obtained in the step S2 into a mould, heating and pressing for molding to obtain the wear-resistant tableware containing the modified plant fibers.

Preferably, in the step S2, the temperature for heating and pressure forming is 155-165 ℃, the pressure is 30-40MPa, and the time is 60-150S.

Preferably, the antioxidant is one or a mixture of several of antioxidant 168, antioxidant 1076 and antioxidant DLTP.

Preferably, the preparation method of the melamine formaldehyde resin comprises the following steps:

adding 100-120 parts by weight of formaldehyde solution with the concentration of 37% into a reactor, adjusting the pH to 9.3-9.5 by using NaOH solution, then heating to 35 ℃, stirring for 0.5-1h until the pH is stable, and then adding 30-40 parts by weight of melamine to react for 2-3h at 90-95 ℃ to obtain the melamine formaldehyde-formaldehyde resin.

The invention has the following beneficial effects:

the method comprises the steps of firstly pretreating the plant fiber by alkali, improving the surface group activity, the surface porosity and the porosity of the plant fiber, then coating and modifying the plant fiber by using a polytetrafluoroethylene emulsion modified by potassium titanate whisker and nano titanium dioxide, forming a potassium titanate whisker-nano titanium dioxide modified polytetrafluoroethylene layer on the surface of the plant fiber, finally carrying out dipping treatment by using a dopamine hydrochloride solution, and forming a polydopamine crosslinking layer on the surface of the modified polytetrafluoroethylene layer by utilizing the self-polymerization-crosslinking reaction of dopamine in water, thereby obtaining the modified plant fiber. Wherein, the alkali treatment is beneficial to improving the surface porosity of the plant fiber, thereby improving the load performance and the bonding force of the polymer emulsion and the plant fiber; the modified polytetrafluoroethylene layer formed by compounding the potassium titanate whiskers, the nano titanium dioxide and the polytetrafluoroethylene emulsion can effectively improve the surface hardness and lubricity of the plant fibers, so that the wear resistance of the plant fibers is improved; the polydopamine crosslinking layer is regenerated on the surface of the modified polytetrafluoroethylene layer, so that the compatibility and the binding force of the polydopamine crosslinking layer with resin can be improved, the modified plant fibers can be more uniformly dispersed in a resin matrix, the enhancement and the wear resistance of the modified plant fibers can be better exerted, and the mechanical property and the wear resistance of the tableware can be further improved. The modified plant fiber prepared by the invention has high strength and excellent wear resistance, and has extremely high compatibility and bonding force with melamine resin materials, so that tableware prepared by taking the modified plant fiber as a filler has excellent wear resistance and mechanical property, high color fastness, difficult fading and strong durability.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.