CN1237211C - Cement concrete reinforced polyethylene fiber and its manufacturing method - Google Patents

Abstract

The invention discloses a cement concrete reinforced polyethylene fiber and a preparation method thereof. Polyethylene resin with a molecular weight of 800,000 to 5 million is used to dissolve decahydronaphthalene, and then extrude, spin and draw through special-shaped spinneret holes, and the obtained frozen After the glue thread is volatilized and dried by decahydronaphthalene, the surface treatment agent is absorbed by the oil pan oiling device equipped with an aqueous solution of alkyl ethanolammonium phosphate, and then fully drawn in the hot tunnel, and cut by a cutting machine to obtain cement concrete reinforced polyethylene. Fiber; it is characterized in that the molecular weight is 800,000-5,000,000, has a special-shaped cross section, the fineness of the fiber is 2.1-14d, the strength is 21-35g/d, the modulus is 56-90GPa, and the elongation at break is 4-6%, including surface treatment The amount of the agent alkyl ethanolammonium phosphate is 0.1-8%, which can be used for cement and concrete reinforcement.

Description

Cement concrete reinforced polyethylene fiber and its manufacturing method

field of invention

The invention relates to a polyethylene fiber and a manufacturing method thereof, in particular to a polyethylene fiber for cement concrete reinforcement and a manufacturing method thereof.

Background technique

Use dispersed fibers to strengthen cement concrete, improve the brittleness of cement substrates, and improve the crack resistance, toughness, blast resistance and impact resistance, impermeability, frost resistance and durability of cement and its concrete to varying degrees properties, tensile, flexural (bending) strength, which can further expand the scope of use of cement and its concrete. In the past, the fibers used for cement and concrete reinforcement were mainly asbestos fibers, steel fibers, glass fibers, and carbon fibers. However, steel fiber or glass fiber has poor corrosion resistance, carbon fiber is expensive, and asbestos fiber has been found to be carcinogenic and its use is restricted. The research, development and application of various cement and synthetic fibers for concrete reinforcement are developed under this background. . Among them, polyolefin fibers have broad application prospects due to their excellent chemical resistance, light specific gravity and low cost.

The tensile strength of the cement paste is 3-6MPa, the elastic modulus is 10-25GPa, and the ultimate elongation is 0.01-0.05%; the tensile strength of the cement mortar is 2-4MPa, the elastic modulus is 25-35GPa, and the ultimate elongation The rate is 0.005-0.015%; the tensile strength of cement concrete is 1-4MPa, the elastic modulus is 30-40GPa, and the ultimate elongation rate is 0.01-0.02%. When used as a reinforcing material for cement and concrete, the strength and modulus of the fiber, especially the modulus, should be higher than the above indicators. EP0743380, EP0091547, JP6313207, CN1071652, CN1147572, etc. have improved the strength and modulus of polypropylene fibers by improving the spinning process, but because the modulus indicators are all below 8GPa, which is lower than that of cement, they cannot achieve reinforcement.

CN1071652A, Chinese application 96116519.7, JP7267709, JP890287189, GB1130612, US4261754 and other patent documents disclose methods for the anti-cracking of cement and concrete with special-shaped cross-section polypropylene fibers. In the existing conventional synthetic fiber technology, special-shaped cross-section synthetic fibers are usually used to improve the hand feel, resilience, pilling, gloss and other properties of fibers. At present, special-shaped cross-section synthetic fibers have been widely used to make bulky fabrics, knitted fabrics, weft Knitting, wool, carpet, etc., but so far there has been no report of spinning polyethylene fibers with special-shaped cross-sections from high-molecular-weight polyethylene solutions.

content of the invention

The object of the present invention is to provide a kind of polyethylene fiber and its manufacture method for reinforcing cement and concrete thereof, described polyethylene fiber has profiled section, high strength and modulus, especially its modulus is higher than cement and its The modulus of concrete, and has good dispersibility and adhesion with cement substrates, and has excellent cement concrete reinforcement performance.

In order to achieve the above object, the technical solution adopted in the present invention is, a cement and its concrete reinforced polyethylene fiber and its manufacturing method, using polyethylene resin with a molecular weight of 800,000-5 million, dissolving it in a solvent and extruding it through a special-shaped spinneret hole Spinning and drawing to obtain polyethylene fibers with special-shaped cross-sections with a strength ≥ 20g/d (1709MPa) and a modulus ≥ 500g/d (43GPa); surface treatment of the fibers with alkyl ethanolammonium phosphate improves the moisture content of the fibers. Dispersion and affinity with cement, so that the obtained fiber has excellent cement concrete reinforcement performance.

The cement concrete reinforced polyethylene fiber manufactured according to the above method has a special-shaped section, the molecular weight is 80-5 million, the length of the fiber is 5-10mm, the fineness of the fiber is 2.1-14d, the strength is 21-35g/d, and the modulus is 56-90GPa, the elongation at break is 4-6%, and the content of the surface treatment agent ethanolammonium alkyl phosphate is 0.5-5wt%.

In the cement concrete reinforced polyethylene fiber of the present invention, the alkyl ethanolammonium phosphate is triethanolammonium dodecyl phosphate and diethanolammonium octyl phosphate. Wherein the molecular weight of the polyethylene fiber is 1-3 million, has a non-circular cross-section, the fineness of the fiber is 2.1-4.7d, the length of the fiber is 5-10mm, the strength is 25-35g/d, and the modulus is 60- 90GPa, the elongation at break is 4-6%, and the amount of alkyl ethanolammonium phosphate attached to the surface is 0.5-5wt%.

The preparation method of the cement concrete reinforced polyethylene fiber of the present invention is as follows: use polyethylene resin with a molecular weight of 80-5 million, dissolve through decahydronaphthalene, extrude spinning and drawing through the spinneret hole, and obtain the jelly yarn through decahydro After the naphthalene is volatilized and dried, the alkyl ethanolammonium phosphate is sucked by the oil pan oiling device equipped with the aqueous solution of the alkyl phosphate ethanol ammonium, and then drawn in the hot tunnel, and cut by a cutting machine to obtain cement concrete reinforced polyethylene fibers. Specifically, the preparation method of the cement concrete reinforced polyethylene fiber of the present invention is: mixing polyethylene resin powder with a molecular weight of 800,000-5 million and decahydronaphthalene in a ratio of 7:93-40:60; Swell at 97°C for 2.5 hours, feed into a twin-screw dissolving extruder through a feeding device to dissolve and extrude, control the temperature of the extrusion solution at 210°C, extrude through a pre-filter and a metering pump spinneret hole, and obtain jelly filament After decahydronaphthalene is volatilized and dried, the 8-12 carbon alkyl ethanolammonium phosphate is adsorbed by an oil pan oiling device equipped with 5-30% aqueous solution of 8-12 carbon alkyl ethanolammonium phosphate, and then heated at 115-145 ° C It is drawn in the hot tunnel at high temperature and cut by a cutting machine to obtain cement concrete reinforced polyethylene fibers.

The spinneret holes in the above method are spinneret holes with special-shaped cross-sections.

The polypropylene or polyethylene fiber that is used for cement concrete reinforcement in the prior art, adopts conventional molecular weight (molecular weight 5-350,000) to make through conventional melt-spinning process, and its strength and modulus, especially modulus are far lower It depends on the modulus of cement and its concrete, so it can prevent cracking and impermeability after being added to cement and its concrete matrix, but it cannot strengthen it. The present invention adopts ultra-high molecular weight polyethylene (molecular weight 80-5 million), the stock solution preparation process of dissolving in solvent and jelly spinning process, makes the fiber of intensity and modulus higher than cement and its concrete, adds to cement and its The concrete matrix can prevent cracking and strengthen at the same time. The molecular weight of the polyethylene resin described in the present invention is preferably 1 million to 3 million.

In the prior art, polypropylene fibers with special-shaped cross-sections are used for anti-cracking of cement concrete. The invention adopts the ultra-high molecular weight polyethylene jelly spinning process to prepare the special-shaped cross-section polyethylene fiber whose strength and modulus are higher than that of the cement concrete base material, and can simultaneously prevent cracking and strengthen the cement and its concrete.

The "special-shaped cross-section polyethylene fiber" in the present invention refers to any cross-sectional shape of polyethylene fiber whose cross-section is non-circular, which is conducive to increasing its contact area with cement and its concrete and the mosaic effect. It can also be a A combination of the above sections. The special-shaped surface can be "trilobal", "flat", "cross", "five-leaf", "quincunx", "snowflake", etc., such cross-sectional shape can make the rigidity of the fiber better Improvement is beneficial to dispersion and avoids entanglement into agglomerates. At the same time, the polyethylene fiber of the present invention can fully contact with cement.

"Alkyl ethanolammonium phosphate" in the present invention refers to a compound having the following chemical structure:

Wherein m=1-3, n=1-3, R is an alkane of 8-12C.

JP6248506, JP6219797, EP0535373 etc. have once mentioned the method that relevant " alkyl phosphate alkali metal salt " is used to prevent the surface treatment of cement and its concrete cracking polypropylene fiber, and the inventor finds, " alkyl ethanolammonium phosphate " It has better water dispersibility and adhesion to polyethylene fibers. Because when the alkyl phosphate ethanolamine salt reacts and bonds with the chemical components in the cement concrete matrix, part of the ethanolamine can be replaced. Ethanolamine is an additive for the production of high-quality cement. It can not only prevent cement agglomeration, but also increase the fluidity and curing performance of cement, thereby improving the compatibility between the fiber and the cement concrete matrix interface. Therefore, the non-toxicity of alkyl phosphoric acid Metal salts - alkyl phosphoric acid and ethanolamine compounds (monoethanolamine, diethanolamine, triethanolamine) produce alkylphosphoethanolamine salts that have better water dispersibility and adhesion to polyethylene fibers. In addition, because the alkyl (R) part of the carbon chain of the alkyl phosphate ethanol ammonium oligomer of the present invention has good affinity with the polyethylene carbon chain, and the terminal group ethanolammonium phosphate part has a good affinity with cement and its concrete It has affinity and cohesiveness, which plays a role in the connection between fiber and cement and its concrete.

The alkyl ethanolammonium phosphate oligomer of the present invention can be formulated into a 0.5-30% aqueous solution, and the fibers can be adsorbed on the oil pan on the spinning process. After the fiber is heated and drawn in the subsequent stage, the water evaporates, and the amount of the oligomer adsorbed on the fiber is 0.1-8% of the weight of the fiber, preferably 0.5-5%.

The present invention adopts polyethylene with a molecular weight of 800,000 to 5,000,000, and after being dissolved in a solvent, it is extruded through special-shaped spinneret holes for spinning and drawing, and the fiber is adsorbed on the oil pan on the spinning process to absorb the surface treatment agent alkyl ethanolammonium phosphate, Obtain polyethylene fibers with special-shaped cross-section and adsorbed treatment agent, and obtain strength and modulus, especially polyethylene fibers whose modulus is greater than the corresponding value of cement. The special-shaped cross-section and the adsorbent on the surface improve the contact interface between cement and fiber, Affinity and cohesion, the cement concrete reinforced polyethylene fiber of the present invention is used for cement reinforcement, which can improve the flexural strength, impermeability and impact resistance of cement.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, and the described embodiments are used to describe the present invention rather than limit the present invention.

Description of drawings

Fig. 1 is the orifice shape of manufacturing special-shaped fiber spinneret in an embodiment of the present invention;

Fig. 2 is the orifice shape of manufacturing special-shaped fiber spinneret in another embodiment of the present invention;

Fig. 3 is the shape of the orifice of the special-shaped fiber spinneret in another embodiment of the present invention.

Detailed ways

Reference example

Mix polyethylene resin powder with a molecular weight of 2 million and decahydronaphthalene at a ratio of 20:80, swell the suspension in a reactor at 97°C for 2.5 hours, and feed it into a twin-screw dissolving extruder through a feeding device for dissolution and extrusion. The temperature of the extrusion solution is controlled at 210°C, and it is extruded from a Y-shaped special-shaped cross-section spinneret through a pre-filter and a metering pump. The oil pan oiling device of the triethanolammonium aqueous solution absorbs the surface treatment agent, and then fully draws it in the hot tunnel at a temperature of 115-145 ° C. After being cut by a cutting machine, the short fiber obtained has a fineness of 4.7d, a length of 7mm, and a strength of 25.6g/d, the modulus is 812g/d (69.4GPa), the elongation at break is 5.1%, and the amount of surface treatment agent is 1.4%. The fiber was added to the concrete with 0.2% volumetric dosage (1.8kg/m ³ ) of cement (Xiang brand 525 ordinary Portland cement): sand: stone: water in the ratio of 1:2:3:0.6, and controlled steaming The culture temperature is below 100℃, and the flexural strength test body is 10×10×40cm ³ , the flexural strength of the control group (without fiber) is 4.0MPa, and the fiber mixed group is 5.7MPa; the compressive strength test body is 10×10×10cm ³ , The compression resistance of the control group (without fiber) is 29.0MPa, and that of the fiber-mixed group is 31.6MPa. Other properties are: impermeability (tested according to GBJ82-85) increased by 70%; impact resistance (tested according to GB/T15231.5-94) Improvement by 25.8%.

Example 1

Others are the same as the reference example, mix the polyethylene resin powder and decahydronaphthalene in proportion, the suspension is swelled in the reactor at 97°C for 2.5 hours, fed into the twin-screw dissolving extruder through the feeding device to dissolve and extrude, and extrude the solution The temperature is controlled at 210°C, and it is extruded from the Y-shaped special-shaped cross-section spinneret through the pre-filter and the metering pump. The oil device absorbs the surface treatment agent, and then fully draws it in the hot tunnel at a temperature of 115-145 ° C, and cuts it by a cutting machine to obtain short fibers. The difference is that the polyethylene resin powder with a molecular weight of 950,000: decahydronaphthalene is a mixed suspension of 30:70, and the Y-shaped special-shaped spinneret hole of a larger size, the concentration of the aqueous solution of triethanolammonium dodecyl phosphate 20%; the length 10mm of the short fiber obtained after being cut by the cutting machine, the fineness is 13.6d, the strength is 21g/d, the modulus is 657g/d (56GPa), the elongation at break is 4.3%, and the amount containing the surface treatment agent is 0.1 wt%. Add this fiber with 0.2% volume dosage (1.8kg/m ³ ) to cement (Xiang brand 525 ordinary portland cement): sand: stone: water is 1: 2: 3: 0.6 concrete, and control steam The culture temperature is below 100°C, and the flexural strength test body is 10×10×40cm ³ , the flexural strength of the control group (without fiber) is 4.0MPa, and the fiber mixed group is 5.1MPa; the compressive strength test body is 10×10×10cm ³ , The compression resistance of the control group (without fiber) was 29.0MPa, and that of the fiber-mixed group was 29.8MPa.

Example 2

Other is the same as embodiment 1 or reference example, adopts flat type (rectangular) spinneret orifice, and difference is that the polyethylene resin powder that adopts molecular weight is 3,000,000: decahydronaphthalene is the mixed suspension of 10: 90, cuts off through cutting machine The length 5mm of post-gained staple fiber is 2.1, and intensity is 35g/d, and modulus is 1050g/d (90GPa), and elongation at break 4.0%, and the amount containing surface treatment agent triethanolammonium dodecyl phosphate is 5wt %. The flexural strength is increased by 55%, the compressive strength is increased by 10%, the impermeability is increased by 72%; the impact resistance is increased by 30%.

Example 3

Other is the same as embodiment 1 or reference example, and difference is that surface treatment agent is diethanolammonium octyl phosphate, adopts cross-shaped special-shaped spinneret holes, and molecular weight is 5 million polyethylene resin powders: decahydronaphthalene is 7: 93 The mixed suspension of the obtained short fiber after being cut by a cutting machine has a length of 7mm, a fineness of 3.4d, a strength of 34g/d, a modulus of 1053g/d (90GPa), and an elongation at break of 6.0%. The amount of diethanolammonium base phosphate is 0.5 wt%. The flexural strength is increased by 56%, the compressive strength is increased by 10%, the impermeability is increased by 73%; the impact resistance is increased by 31%.

Example 4

Others are with embodiment 1 or reference example, and difference is that surface treatment agent is decanyl monoethanolammonium phosphate, adopts five-lobed special-shaped spinneret hole, molecular weight is the polyethylene resin powder of 800,000: decahydronaphthalene is 40: 60 mixed suspension, the length of the short fiber obtained after being cut by a cutting machine is 10mm, the fineness is 14d, the strength is 21g/d, the modulus is 676g/d (58GPa), the elongation at break is 4.2%, and the surface treatment agent decane is contained. The amount of monoethanolammonium base phosphate is 8 wt%. Experiments have shown that it can improve the performance of cement and its concrete.

Example 5

Others are the same as embodiment 1 or reference example, and the difference is that the surface treatment agent is monoethanolammonium decyl phosphate, adopts plum-shaped special-shaped spinneret holes, and the molecular weight is 1,000,000 polyethylene resin powder: decahydronaphthalene is 40: 60 The mixed suspension of the obtained short fiber after being cut by a cutting machine has a length of 8mm, a fineness of 9d, a strength of 23g/d, a modulus of 62GPa, and an elongation at break of 4%. The amount is 3 wt%. The flexural strength is increased by 38%, the compressive strength is increased by 8%, the impermeability is increased by 68%, and the impact resistance is increased by 27%.

Claims (9)

1. A cement concrete reinforced polyethylene fiber is characterized in that the molecular weight of the polyethylene fiber is 80-5 million, has a non-circular section, the fineness of the fiber is 2.1-14d, and the length of the fiber is 5-10mm, The strength is 21-35g/d, the modulus is 56-90GPa, the elongation at break is 4-6%, and the amount of alkyl phosphate ethanol ammonium attached to the surface is 0.1-8wt%. 2. a kind of cement concrete reinforced polyethylene fiber according to claim 1, is characterized in that the structure of described alkyl ethanolammonium phosphate is:

Wherein m=1-3, n=1-3, R is an alkane with 8-12 carbons. 3. A kind of cement concrete reinforced polyethylene fiber according to claim 2, characterized in that said alkyl ethanolammonium phosphate is triethanolammonium dodecyl phosphate or diethanolammonium octyl phosphate. 4. a kind of cement concrete reinforced polyethylene fiber according to claim 1, is characterized in that polyethylene molecular weight is 1,000,000-3,000,000, has non-circular cross-section, and the fineness of fiber is 2.1-4.7d, and the length of fiber is 5-10mm, the strength is 25-35g/d, the modulus is 60-90GPa, the elongation at break is 4-6%, and the amount of alkyl ethanolammonium phosphate attached to the surface is 0.5-5wt%. 5. A cement concrete reinforced polyethylene fiber according to any one of claims 1-3, characterized in that the cross-section is flat, trilobal, quatrefoil, five-lobal, quincunx or snowflake A kind of shape. 6. according to the preparation method of a kind of cement concrete reinforced polyethylene fiber described in any one of claim 1-3, it is characterized in that with the polyethylene resin that molecular weight is 80-5,000,000, after decahydronaphthalene is dissolved, by spinning Hole extrusion spinning and drawing, after decahydronaphthalene volatilization and drying of the obtained jelly yarn, the alkyl ethanolammonium phosphate is absorbed by the oil pan oiling device equipped with an aqueous solution of alkyl ethanolammonium phosphate, and then drawn in the hot tunnel , After being cut by a cutting machine, the cement concrete reinforced polyethylene fiber is obtained. 7. The preparation method of a kind of cement concrete reinforced polyethylene fiber according to claim 6, characterized in that polyethylene resin powder and decahydronaphthalene with a molecular weight of 80-5 million are mixed according to the ratio of 7:93-40:60 , the suspension was swelled in the reactor at 97°C for 2.5 hours, fed into the twin-screw dissolving extruder through the feeding device to be dissolved and extruded. Extrude, after the obtained jelly silk is volatilized and dried by decahydronaphthalene, the 8-12 carbon alkyl ethanolammonium phosphate is adsorbed by an oil pan oiling device equipped with a 5-30 wt% aqueous solution of 8-12 carbon alkyl ethanolammonium phosphate , and then drawn in a hot shaft at a temperature of 115-145 ° C, and then cut by a cutting machine to obtain cement concrete reinforced polyethylene fibers. 8. A method for preparing cement concrete reinforced polyethylene fibers according to claim 7, characterized in that the polyethylene has a molecular weight of 1-3 million. 9. according to the preparation method of a kind of cement concrete reinforced polyethylene fiber described in any one of claim 6-8, it is characterized in that the cross-section of described polyethylene is flat, trilobal, quatrefoil or snowflake-shaped kind of.