阅读说明：本技术 一种聚氨酯凝胶泡沫及其制备方法 (Polyurethane gel foam and preparation method thereof ) 是由 袁振 王少华 王宇川 于 2020-05-26 设计创作，主要内容包括：本发明提供了一种聚氨酯凝胶泡沫及其制备方法,所述凝胶泡沫包括以下原料：聚醚多元醇、异氰酸酯、催化剂、扩链剂、水、物理发泡剂、吸水性树脂,扩链剂为聚乙烯胺。将线型聚乙烯胺引入交联网络结构的聚氨酯中,最后形成相互贯穿的交联网络,这种三维交联网络高分子吸水可形成凝胶,赋予聚氨酯凝胶泡沫良好的吸水性能,可反复吸水、脱水使用。少量吸水性树脂的加入,具有协同聚乙烯胺提高聚氨酯凝胶泡沫拉伸强度的作用。本发明制备的聚氨酯泡沫未吸水前为海绵体,吸水后溶胀为水凝胶,作为线缆保护套或保护盒防水封堵材料,能够有效阻挡水分通过,具有明显的经济效益和社会效益。(The invention provides polyurethane gel foam and a preparation method thereof, wherein the gel foam comprises the following raw materials: polyether polyol, isocyanate, a catalyst, a chain extender, water, a physical foaming agent and water-absorbent resin, wherein the chain extender is polyvinylamine. Linear polyvinylamine is introduced into polyurethane with a cross-linked network structure, and finally a cross-linked network which is mutually penetrated is formed, and the three-dimensional cross-linked network polymer absorbs water to form gel, so that the polyurethane gel foam has good water absorption performance and can be repeatedly used for water absorption and dehydration. The addition of a small amount of water-absorbent resin has the function of improving the tensile strength of polyurethane gel foam by cooperating with polyvinylamine. The polyurethane foam prepared by the invention is a sponge before absorbing water, swells into hydrogel after absorbing water, can effectively prevent water from passing through as a waterproof plugging material of a cable protective sleeve or a protective box, and has obvious economic and social benefits.)

1. A polyurethane gel foam comprises the following raw materials: polyether polyol, isocyanate, a catalyst, a chain extender, water, a physical foaming agent and water-absorbent resin, and is characterized in that the chain extender is polyvinylamine.

2. The gel foam of claim 1, wherein the gel foam comprises the following raw materials in parts by weight: 100 parts of polyether polyol, 50-110 parts of isocyanate, 1-3 parts of catalyst, 3-10 parts of chain extender, 0.5-1 part of water, 1-3 parts of physical foaming agent and 5-10 parts of water-absorbent resin.

3. The gel foam of claim 2, wherein the isocyanate is present in an amount of 60 to 90 parts by weight and the chain extender is present in an amount of 5 to 10 parts by weight.

4. A gel foam according to any of claims 1 to 3, wherein the polyvinylamine has a number average molecular weight of 40000 and 80000 and a degree of amination of 35 to 60%.

5. The gelled foam of claim 1, wherein the isocyanate is selected from at least one of a polyisocyanate, a polyisocyanate; preferably, the isocyanate has a functionality > 2 and an NCO content of 5 to 20%.

6. A gelled foam according to claim 5, wherein the isocyanate is selected from at least one of 4, 4', 4 "triphenylmethane triisocyanate, TDI trimer and HDI trimer.

7. The gel foam of claim 1, wherein the polyether polyol has a functionality of 2 to 3 and a hydroxyl number of 30 to 40 mgKOH/g.

8. The gel foam of claim 1, wherein the water-absorbent resin comprises a polyacrylamide derivative, a polyacrylate derivative, and at least one selected from the group consisting of polyacrylamide, sodium polyacrylate, and polycyclopropylacrylamide.

9. A process for preparing a polyurethane gel foam as claimed in any one of claims 1 to 8, comprising the steps of:

s1, respectively dehydrating polyether polyol and isocyanate at high temperature in vacuum, and cooling; adding isocyanate and a catalyst into polyether polyol under the stirring condition, heating, keeping constant temperature, stirring for reaction, and cooling to obtain a prepolymer;

s2, uniformly mixing the chain extender, the physical foaming agent and the water-absorbent resin, adding the mixture and water into the prepolymer prepared in the step S1, stirring at a high speed, quickly pouring the mixture into a mold when the mixture begins to foam, standing, putting the mixture into an oven for curing, finally taking out and cooling to obtain the polyurethane gel foam.

10. The method for preparing gel foam according to claim 9, wherein the polyether polyol and the isocyanate are dehydrated at 80-120 ℃ and cooled to 20-40 ℃ after dehydration in step S1; the reaction temperature is 70-100 ℃, and the reaction time is 1-3 h; and/or the standing time in the step S2 is 10-30min, the curing temperature is 60-90 ℃, and the curing time is 1-3 h.

Technical Field

The invention belongs to the technical field of high polymer material foamed plastics, and particularly relates to polyurethane gel foam and a preparation method thereof.

Background

The electric power industry in China develops rapidly, the application amount of electric power facilities, especially cables and wires is very big, in order to make the cables and wires adapt to various indoor and outdoor environments, protective devices are generally additionally arranged on the cables and wires, the service life of the protective devices is prolonged, the protective devices which are commonly used are provided with cable protective sleeves and cable protective boxes, however, the water seepage problem generally existing at the end parts of the protective sleeves or the cable protective boxes can cause the traditional flange sealing device to be corroded, the protective effect can not be normally exerted, and the sealing by using a plugging material is a good method.

Polyurethane is polyurethane, which is called polyurethane for short, and can be made into various materials such as plastics, rubber, fibers, paint, adhesives and the like. The flexible polyurethane sheet foam is a polyurethane foam with certain elasticity and flexibility, and accounts for the largest part in a foam product, and the yield of the flexible polyurethane sheet foam is more than half of the yield of the whole polyurethane foam. The soft foam has the characteristics of low density, good elastic recovery performance, sound insulation, air permeability and the like, and is widely applied to furniture, seat cushion materials, sound insulation materials, shockproof materials, decorative materials and the like. Many new varieties are newly developed, such as low fogging deformation foam, super soft polyurethane foam, high water absorption polyurethane foam, and the like. The high-water-absorption polyurethane foam is a material with strong water absorption, is foam sponge before water absorption, can expand by multiple times after water absorption, can be applied to the sealing of the end part of the cable protection device, can fill small gullies and holes by utilizing the water absorption expansion of the cable protection device, plays a role of thoroughly stopping water, can save flanges, and greatly reduces the replacement frequency and the labor consumption.

Patent CN200710094074.6 discloses a preparation method of hydrophilic polyurethane foam, which comprises the following steps: (1) excessive polyisocyanate and polyoxyethylene polyol react at 70-120 ℃ to form a terminal NCO-based prepolymer with NCO content less than or equal to 15%, wherein: the polyisocyanate is selected from hexamethylene diisocyanate HDI, diphenylmethane diisocyanate MDI, toluene diisocyanate TDI, xylene diisocyanate TODI and mixture of two or more of the above substances; the polyoxyethylene polyol is polyol with the functionality of more than or equal to 2, the molecular weight of 600-3000 and the EO content of more than or equal to 60 percent; (2) mixing the prepolymer with a large amount of water to form a foam, wherein: the molar ratio of water to prepolymer is more than or equal to 5, and although the polyurethane foam prepared by the method has certain water absorption performance, the expansion ratio after water absorption is small, and the polyurethane foam can not play a role in thoroughly stopping water when being applied to the aspects of sealing and water proofing. Patent CN201710530908.7 discloses a high water absorption and high water retention polyurethane foam and a preparation method thereof, wherein water absorption resin polyacrylate particles and polyacrylamide are added in a blending manner in the preparation process to prepare a foam material with good water absorption and water retention. In the above patent, the water-absorbent resin is blended into the polyurethane foam by physical blending, although the water absorption rate is increased, the water-absorbent resin cannot be used repeatedly, and if the water-absorbent resin is used repeatedly by water absorption and dehydration, the water absorption and water absorption expansion properties of the foam are reduced, and the water cannot be stopped well.

In conclusion, the polyurethane foam material with lasting and good water absorption and water expansion performance is developed, and has an important effect on popularization and application of the polyurethane foam material in the field of sealing and waterproofing.

Disclosure of Invention

Aiming at the technical problems, the invention aims to diffuse and prolong the molecular chain of polyurethane by using the polyvinylamine as a chain extender, introduce linear polyvinylamine into the polyurethane with a cross-linked network structure and finally form a cross-linked network which is penetrated with each other; the three-dimensional cross-linked network polymer can form gel after absorbing water, endows polyurethane gel foam with good water absorption performance, and can be repeatedly used for water absorption and dehydration; compared with the conventional diamine micromolecule chain extender, the polyurethane obtained by chain extension of macromolecular polyvinylamine has good water absorption and expansion performance.

In order to solve the technical problems, the invention adopts the following specific technical scheme:

a polyurethane gel foam, comprising the following raw materials: polyether polyol, isocyanate, a catalyst, a chain extender, water, a physical foaming agent and water-absorbent resin, and is characterized in that the chain extender is polyvinylamine.

The polyurethane gel foam is characterized by comprising the following raw materials in parts by weight: 100 parts of polyether polyol, 50-110 parts of isocyanate, 1-3 parts of catalyst, 3-10 parts of chain extender, 0.5-1 part of water, 1-3 parts of physical foaming agent and 5-10 parts of water-absorbent resin, wherein the chain extender is polyvinylamine.

The polyvinylamine is a water-soluble chain high polymer material, the side chain contains a large amount of high-reactivity amine groups, and the amine groups can react with isocyanic acid radicals.

Preferably, the isocyanate is used in an amount of 60-90 parts, and the chain extender is used in an amount of 5-10 parts.

The physical foaming agent is a low-boiling point foaming agent and comprises at least one of hexane, isohexane, propane and dichloromethane.

The polyvinylamine is prepared by Hofmann degradation rearrangement of polyacrylamide or by hydrolysis of (N-methyl/acetamide) vinylamine, the number average molecular weight of the polyvinylamine is 40000-80000, and the amination degree is 35-60%.

The isocyanate has a functionality of > 2 and an NCO content of 5-20% and comprises at least one of polyisocyanate and polyisocyanate.

The isocyanate includes but is not limited to at least one of 4, 4' -triphenylmethane triisocyanate, TDI trimer and HDI trimer.

The polyether polyol has a functionality of 2-3 and a hydroxyl value of 30-40mgKOH/g (number average molecular weight of 2000-6500).

The catalyst is not particularly limited, and an organic tin catalyst commonly used in the art may include at least one of dibutyltin dilaurate and stannous octoate.

The polyurethane gel foam also comprises the following raw materials in parts by weight: 1-3 parts of foam stabilizer.

The water-absorbent resin comprises polyacrylamide derivatives and polyacrylate derivatives, and is specifically selected from at least one of polyacrylamide, sodium polyacrylate and poly (cyclopropyl acrylamide).

The foam stabilizer is an organosilicon foam stabilizer, and is specifically selected from one or more of AK-8818, B8525, B8545, DC5598 and DC 193.

The invention also provides a preparation method of the polyurethane gel foam, which comprises the following steps:

s1, respectively dehydrating polyether polyol and isocyanate at high temperature in vacuum, and cooling; adding isocyanate and a catalyst into polyether polyol under the stirring condition, heating, keeping constant temperature, stirring for reaction, and cooling to obtain a prepolymer;

s2, uniformly mixing the chain extender, the physical foaming agent and the water-absorbent resin, adding the mixture and water into the prepolymer prepared in the step S1, stirring at a high speed, quickly pouring the mixture into a mold when the mixture begins to foam, standing, putting the mixture into an oven for curing, finally taking out and cooling to obtain the polyurethane gel foam.

Step S1, dehydrating the polyether polyol and the isocyanate at 80-120 ℃, and cooling to 20-40 ℃ after dehydration; the reaction temperature is 70-100 ℃, and the reaction time is 1-3 h;

and step S2, standing for 10-30min, curing at 60-90 deg.C for 1-3 h.

Compared with the prior art, the invention has the beneficial effects that:

firstly, by using polyvinylamine as a chain extender, not only polyurethane molecular chains are diffused and prolonged, but also linear polyvinylamine is introduced into polyurethane with a cross-linked network structure, and finally a cross-linked network which is penetrated through each other is formed; the three-dimensional cross-linked network polymer can form gel after absorbing water, endows polyurethane gel foam with good water absorption performance, and can be repeatedly used for water absorption and dehydration; compared with the conventional diamine micromolecule chain extender, the polyurethane obtained by chain extension of macromolecular polyvinylamine has good water absorption and swelling properties.

Secondly, the inventors have unexpectedly found that the addition of a small amount of water-absorbent resin has the effect of improving the tensile strength of the polyurethane gel foam in cooperation with polyvinylamine.

The polyurethane foam prepared by the invention is a sponge body when not absorbing water, swells into hydrogel after absorbing water, has wide application range, can effectively prevent water from passing through particularly as a waterproof plugging material of a cable protective sleeve or a protective box, and has obvious economic benefit and social benefit.

Detailed Description

The present invention will be further described with reference to the following examples, but the present invention is not limited to the descriptions in the following. Unless otherwise specified, the parts of the reagents are parts by weight. All reagents used are commercially available in the art.

Polyvinylamine is purchased from Wuhan Bolei chemical Co., Ltd.

In the examples of the present invention, "part" means part by weight unless otherwise specified.