CN1062211C - Preparation method of sisal fibre-resin base composite material - Google Patents

Abstract

The present invention provides a method. Sisal fiber is used as a raw material of fiber; thermoplastic resin PVC or phenolic resin PF of thermosetting resin or epoxy resin EPo is used as a base body of resin; after pre-processing and short cutting of filament bundles are carried out to filament bundles of fiber or weaved cloth, short fiber or the weaved cloth is mixed with the raw material of the base body of resin; after drying is carried out, hot-press forming is carried out under certain temperature and pressure conditions, and the sisal fiber enhanced thermoplastic resin and a composite material of thermosetting resin are obtained. The method of the present invention has the advantages of simple process, less pollution, wide range of application, controllable content of the fiber of a product from 10% to 65% by weight and small specific weight of the product, and has high specific strength and specific modulus.

Description

Preparation method of sisal fiber/resin matrix composite material

The invention belongs to the preparation method of sisal fiber/resin matrix composite material.

In the existing sisal fiber/resin-based composite material preparation method, there are people such as C.Pavithran adopting the unidirectional sisal fiber/unsaturated polyester laminated composite material prepared by hot pressing method, or unidirectional sisal fiber and unidirectional To glass fiber hybrid/unsaturated polyester laminated composites (Journal of Materials Seience Letters, 1987, 6, P882-884, 1988, 7, P825-826.Journal of Metrials Science, 1991, 26, P455-459), This process first needs to prepare unidirectional sisal fiber impregnated resin non-weft fabric. Since the length of sisal fiber formed by natural growth is generally only 1 to 1.4 meters, it is difficult to prepare continuous non-weft fabric. In addition, this process only It is suitable for the preparation of unidirectional sisal fiber and unsaturated polyester composite material.

J.Giridhar et al prepared unidirectional sisal fiber/epoxy resin laminated composites (Journal of Reinforccd Plastics and Composites, 1986, 5, P141-150) by hot pressing. Sisal fiber/epoxy free weft and is only suitable for epoxy resin substrates.

Kuruvilla Joseph and others used two processes of melt blending and solution blending to manufacture short sisal fiber/low-density polyethylene composite materials. The disadvantage of the melt blending method is that the damage to the sisal fiber is serious, resulting in a decline in the performance of the composite material. However, the solution mixing process needs to use a large amount of toxic solvents, causing environmental pollution, and the cost is also high.

The purpose of the invention is to establish a production method with simple process, wide application range and low pollution to prepare short sisal fibers and sisal fiber woven cloth reinforced thermoplastic resin and thermosetting resin composite materials.

The inventive method is used for preparing sisal fiber/resin-based composite material, by raw material sisal fiber (hereinafter referred to as SF) tow or woven cloth after pretreatment, tow is cut short, short fiber or woven cloth and quantitative resin matrix After the raw materials are mixed and dried, they are hot-pressed and formed under certain temperature and pressure conditions to obtain a composite material with a fiber weight content of 10-56%. The specific process is as follows:

①Preparation of sisal fiber raw material: After the raw sisal fiber tow or woven cloth is pretreated, the tow is cut short to obtain a chopped strand with a linear density of 10-70 tex and a fiber length of 3-10mm. SF or SF woven cloth is used as the sisal fiber raw material for preparing composite materials;

② Mixing: sisal fiber raw material and resin matrix raw material are evenly mixed, and dried if necessary;

③Hot press molding: Put the mixture of sisal fiber and resin into the preheated mold, heat it to a certain temperature, pressurize it under a certain pressure in the press for a certain period of time, and then release the pressure and eject the mold to obtain a composite material.

The pretreatment of raw sisal fiber can adopt methods such as drying, heat treatment, alkali treatment, acetylation, silane treatment, etc. The sisal fiber tow or woven cloth before treatment is referred to as SF or SF cloth.

Drying method: Put SF or SF cloth in an oven at 100°C to dry, and the obtained sisal fiber raw material is called USF or USF cloth raw material;

Heat treatment method: put SF or SF cloth in an oven at 110-180°C for 1-6 hours, and the obtained sisal fiber raw material is called T-SF or T-SF cloth raw material;

Alkali treatment method: Soak SF or SF cloth in 1-5% sodium hydroxide solution, the bath ratio is 1: (15-30), treat it at room temperature to 80°C for 1-6 hours, and then wash it with tap water until medium Drying at 90-100°C, the obtained sisal fiber raw material is called A-SF or A-SF cloth raw material;

Acetylation treatment method: soak the raw material SF or SF cloth with 18% sodium hydroxide solution for 1-10 minutes, then neutralize with 1-5% sulfuric acid solution, wash with water, and then treat with 40-50% acetic acid solution1 ~ 10 minutes, the bath ratio is 1: (15 ~ 30), the obtained sisal fiber raw material is called HAc-SF or HAc-SF cloth raw material;

Silane treatment method: Soak A-SF or A-SF cloth in 1-10% KH-550 silane-ethanol solution for 1-30 minutes, the bath ratio is 1: (15-30), take it out and dry it in the air at 90- Drying at 100°C, the obtained sisal fiber raw material is called KH-SF or KH-SF cloth raw material.

The resin matrix suitable for this method includes thermoplastic resin such as polyvinyl chloride (PVC), thermosetting resin phenolic resin (PF) and epoxy resin (EP ₀ ).

When PVC is used as the resin matrix, PVC must first be prepared into PVC premix, and then short SF raw material and PVC premix or short glass fiber (hereinafter referred to as GF) and PVC premix or short SF and short GF and PVC premix The mixture is mixed by dry powder mixing method, and the composite material is prepared by hot pressing. The specific process is as follows:

Dry the low-viscosity PVC powder synthesized by the suspension method at 70-80°C, take 100 parts and put it into a high-speed mixer preheated to 70-80°C, add 3-5 parts of stabilizer M-103 organotin and flame retardant 3-5 parts of tricresyl phosphate, stir and heat at a speed of 600-1200 rpm when starting the machine, when the temperature of the material rises to 105-115°C, add 1-2 parts of stabilizer calcium stearate, lubricant stearic acid 0.5 to 1 part and 1 to 2 parts of butyl stearate, continue to stir and heat, the material temperature rises to 125 to 135 ° C and then starts to cool down, and then drops to 70 to 75 ° C to add plasticizer dioctyl phthalate ( DOP) 0 to 20 parts, paraffin wax 0.5 to 1 part, continue mixing for 2 to 3 minutes, stop stirring when the temperature of the material drops below 65°C, and obtain a PVC premix. Mix 0-27.4 parts of chopped SF raw materials and 0-43 parts of chopped GF raw materials dried below 100°C with PVC premix at high speed for 1-2 minutes to obtain a mixture of fiber raw materials and resin matrix; then put the mixture into Put it into a metal mold preheated to 100-120°C, continue to heat to 150-180°C, place it on a hydraulic press for hot pressing, press 35-40MPa, cool the mold below 70°C and eject it, and obtain short SF reinforced PVC composite The material is short GF reinforced PVC composite material or short SF and short GF mixed reinforced PVC composite material, and the fiber weight content in the composite material can be controlled at 5-30%.

When the resin matrix used is a thermosetting phenolic resin, the following process is used for mixing and molding: mix 10-185 parts of short SF raw materials dried at 100°C with 100 parts of PF glue (ethanol is the solvent, and the solid content is 56%) , Stir evenly, or SF cloth raw material is coated with PF glue quantitatively, dry at 70-80°C to remove the solvent, then put it into a metal mold that has been preheated to 110-120°C, heat to 150-160°C and press for 10 minutes , the pressure is controlled at 20-40MPa, the mold temperature drops below 70°C and the mold is ejected to obtain a short SF-reinforced phenolic resin composite material or an SF cloth-reinforced phenolic resin laminated composite material. The fiber weight content in the composite material can be controlled at 10-65 % or 35-65%.

When the resin matrix used is a thermosetting epoxy resin, the following process is used for mixing and molding: 10-185 parts of short SF raw materials dried at 100 °C and 100 parts of E-51 epoxy resin and 20-25 parts of 593 #The curing agent is mixed evenly (you can add acetone to dilute when the fiber content is high), then put it into a mold preheated to 55-65°C, keep the temperature for 10-15 minutes until the resin starts to gel, then pressurize to 30-40MPa and hold Press for 2 hours, release the pressure and remove the mold and treat at 80° C. for 2 hours to obtain a short SF reinforced epoxy resin composite material. The fiber weight content in the composite material can be controlled at 10-65%.

The method of the present invention adopts the sisal fiber which is rich in resources, cheap but has excellent characteristics such as fiber length, tough texture, elasticity, strong pulling force, friction resistance, acid and alkali resistance, seawater corrosion resistance and low temperature resistance as raw material, and PVC or PF, EP ₀ and other resin matrices are mixed and hot-pressed in a simple process to prepare sisal short fiber or sisal fiber woven cloth reinforced thermoplastic or thermosetting composite materials, and the fiber weight content of the product can be controlled at 10-65%. , and the specific gravity of the composite product is small (between 1.0 and 1.3×10 ³ Kg/m ³ ), therefore, the product composite material has high specific strength and specific modulus.

The following are specific embodiments of the present invention:

Example 1-7: Dry SG-8 low-viscosity PVC powder at 80°C, take 100 parts and put it into a high-speed mixer preheated to 75°C, and add 5 parts of M-103 organotin and tricresyl phosphate 5 parts, start mixing and heating, after 5 minutes, the temperature of the material rises to 110 ° C, then add 1 part of calcium stearate, 0.5 parts of stearic acid and 1 part of butyl stearate, continue mixing for 2 minutes, the temperature of the material rises to After 130°C, the temperature starts to drop, and after 5 minutes, the material temperature drops to 75°C. Add 10 parts of DOP and 0.5 parts of paraffin, and continue mixing for 3 minutes. After the material temperature drops to 65°C, start mixing for 2 minutes, that is Short SF/PVC or short GF/PVC or short SF/GF/PVC dry powder premix can be obtained; put this short fiber PVC premix into a metal mold preheated to 120°C, and continue heating to 160°C, Then hot-press on a hydraulic machine, the pressure is 35MPa, the mold temperature drops to 70°C and the mold is ejected, and the short SF/PVC or short GF/PVC or short SF/GF/PVC composite material can be obtained. The composition and properties of the composite material are shown in Table 1. shown.

Examples 8-12: Dry the short SF raw material below 100°C and quantitatively mix it with 100 parts of PF (56% solid content), stir evenly and then dry it at 70°C to remove the solvent, and place the dried premix in In the mold preheated to 120°C, hot press at 155°C for 10 minutes, the pressure is 35-40MPa, the excess glue is discharged by controlling the pressure, the mold temperature drops below 70°C, the pressure is released, and the short SF/ The composition and properties of PF composite materials are shown in Table 2.

Examples 13-16: Dry the SF cloth raw material below 100°C, then apply PF glue on both sides quantitatively, dry at 75°C to remove the solvent, and then stack the three layers of the glue-coated SF cloth in the same direction Together, put them on an oil press at 155°C for 10 minutes, press 20-40MPa, discharge excess glue by controlling the pressure, and make SF cloth/PF laminated composite material after pressure relief, its composition and properties as shown in Table 3.

Examples 17-19: After drying the short SF raw material below 100°C, quantitatively mix it with 100 parts of E-51 epoxy resin and 20 parts of 593 ^# curing agent, and add the premix into the mold preheated to 60°C Constant temperature for 15 minutes until the resin starts to gel, then pressurize to 35MPa and hold constant temperature and pressure at 60°C for 2 hours, release the pressure and release the mold and cure at 80°C for 2 hours to obtain a short SF/epoxy resin composite material, its composition and properties As shown in Table 4.

Table 1 Composition and properties of short fiber PVC composites ^* Example fiber raw material SF dosage (parts) GF dosage (parts) σb/ρ(×10 ^-3 MPa·m ³ /Kg) Eb/ρ(MPa·m ³ /Kg) αk/ρ(×10 ^-3 KJ·m/Kg) HB/ρ(×10 ^-3 MPa·m ³ /Kg) 1 USF 27.4 0 35.2 1.86 7.4 49.6 2 HAc-SF 27.4 0 30.2 1.80 8.5 57.3 3 KH-SF 27.4 0 32.5 1.69 5.8 49.6 4 T-SF 27.4 0 34.7 1.70 6.6 65.6 5 T-SF/GF 6.8 39.6 32.4 2.04 14.5 52.7 6 T-SF/GF 20.5 13.2 33.8 2.04 10.1 56.9 7 GF 0 52.7 40.1 2.47 14.3 57.1

^* σb/ρ——Specific bending strength, Eb/ρ——Specific bending modulus, αb/ρ——Specific unnotched impact strength, HB/ρ——Specific Brinell strength.

Table 2 Composition and properties of short SF/PF composites Example fiber raw material SF content (%) σb/ρ(×10 ^-3 MPa·m ³ /Kg Eb/ρ(MPa·m ³ /Kg) αk/ρ(×10 ^-3 KJ·m/Kg) HB/ρ(×10 ^-3 MPa·m ³ /Kg) 8 USF 45 70.4 5.71 18.0 142 9 A-SF 45 55.9 5.71 15.5 160 10 KH-SF 45 66.5 6.56 13.0 160 11 KH-SF 55 86.6 6.90 16.9 158 12 KH-SF 25 47.6 4.87 6.10 165

Table 3 Composition and properties of SF/PF laminated composites Example fiber raw material SF content (%) portrait σb/ρ(×10 ^-3 MPa·M ³ /Kg) Eb/ρ(MPa·m ³ /Kg) αk/ρ(×10 ^-3 KJ·m/Kg) 13 USF 65 49.1 4.28 32.2 14 KH-SF 35 56.0 4.81 13.9 15 KH-SF 55 67.3 6.61 16.9 16 KH-SF 65 63.8 6.54 18.9 horizontal σb/ρ(×10 ^-3 MPa·M ³ /Kg) Eb/ρ(MPa·m ³ /Kg) αk/ρ(×10 ^-3 KJ·m/Kg) 13 USF 65 34.8 1.98 17.3 14 KH-SF 35 48.5 1.92 6.10 15 KH-SF 55 54.8 5.02 13.0 16 KH-SF 65 48.6 3.98 13.1

Table 4 Composition and properties of short SF/epoxy composites Example fiber raw material SF content (%) σb/ρ(×10 ^-3 MPa·M ³ /Kg) Eb/ρ(MPa·m ³ /Kg) αk/ρ(×10 ^-3 KJ·m/Kg) HB/ρ(×10 ^-3 MPa·m ³ /Kg) 17 USF 30 62.3 4.00 10.3 95.0 18 A-SF 30 55.0 4.71 7.48 118 19 KH-SF 30 60.7 4.00 6.13 112

Claims (4)

1, a kind of preparation method of sisal fibre-resin base composite material is characterized in that technical process is:

1. the preparation of sisal fiber raw material: after raw material sisal fiber tow or the processing of woven cloth employing preprocess method, tow prescinds, and the weak point that obtains line density and be 10～70 Tekes, fibre length and be 3～10mm is cut sisal fiber or the sisal fiber woven cloth sisal fiber raw material as the preparation composite; Said preprocess method is one of following method:

A. seasoning: the raw material sisal fiber is put into 100 ℃ of baking ovens dry;

B. heat treating process: the raw material sisal fiber is put into 110～180 ℃ of baking ovens dried by the fire 1～6 hour;

C. alkali treatment method: the raw material sisal fiber is soaked in 1～5% the sodium hydroxide solution, bath raio is 1: 15～1: 30, ℃ handled 1～6 hour in room temperature to 80, then with the running water flushing to neutral, in 90～100 ℃ of oven dry;

D. acetylation facture: the raw material sisal fiber was soaked 1～10 minute with 18% sodium hydroxide solution, and then with 1～5% sulfuric acid solution neutralization, with 40～50% acetic acid processing 1～10 minute, bath raio was 1: 15～1: 30 again;

E. silane treatment method: will handle the sisal fiber raw material soaking that obtains in 1～10% KH-550 silane ethanolic solution 1～30 minute through the alkali treatment method, bath raio is 1: 15～1: 30, and taking-up is dried, in 90～100 ℃ of oven dry;

2. batch mixing and hot-forming: the low viscosity PVC powder that suspension method is synthetic is in 70～80 ℃ of dryings, getting 100 parts puts into and is preheated to 70～80 ℃ high-speed mixer, add 3～5 parts of 3～5 parts of stabilizing agent M-103 organotins and fire retardant tricresyl phosphates, start is stirred and heating with 600～1200 rev/mins rotating speed, add 1～2 part of stabilizing agent calcium stearate during material temperature rise to 105～115 ℃, 1～2 part of 0.5～1 part of lubricant stearic acid and butyl stearate, material begins cooling behind temperature rise to 125～135 ℃, reduce to 70～75 ℃ and add plasticizer phthalic acids two sad 0～20 part, 0.5～1 part in paraffin, continue to mix 2～3 minutes, wait to expect to stop below the temperature drop to 65 ℃ stirring, obtain PVC premix.To cut 0～43 part of 0～27.4 part of sisal fiber raw material and short glass fiber raw material through the weak point of oven dry below 100 ℃ mixed 1～2 minute with PVC premix high-speed stirred, taking-up is put into and is preheated to 100～120 ℃ metal die, continue to be heated to 150～180 ℃, moulding on hydraulic press, pressure is 35～40MPa, mould is cooled to below 70 ℃ and moves back mould, obtain short sisal fibers Reinforced PVC composite or short sisal fibers and short glass fiber and mix the Reinforced PVC composite, the fibre weight percentage composition in the composite is controlled at 5～30%.

2, a kind of preparation method of sisal fibre-resin base composite material is characterized in that technical process is:

1. the preparation of sisal fiber raw material: after raw material sisal fiber tow or the processing of woven cloth employing preprocess method, tow prescinds, and the weak point that obtains line density and be 10～70 Tekes, fibre length and be 3～10mm is cut sisal fiber or the sisal fiber woven cloth sisal fiber raw material as the preparation composite; Said preprocess method is one of following method:

A. seasoning: the raw material sisal fiber is put into 100 ℃ of baking ovens dry;

B. heat treating process: the raw material sisal fiber is put into 110～180 ℃ of baking ovens dried by the fire 1～6 hour;

C. alkali treatment method: the raw material sisal fiber is soaked in 1～5% the sodium hydroxide solution, bath raio is 1: 15～1: 30, ℃ handled 1～6 hour in room temperature to 80, then with the running water flushing to neutral, in 90～100 ℃ of oven dry;

D. acetylation facture: the raw material sisal fiber was soaked 1～10 minute with 18% sodium hydroxide solution, and then with 1～5% sulfuric acid solution neutralization, with 40～50% acetic acid processing 1～10 minute, bath raio was 1: 15～1: 30 again;

E. silane treatment method: will handle the sisal fiber raw material soaking that obtains in 1～10% KH-550 silane ethanolic solution 1～30 minute through the alkali treatment method, bath raio is 1: 15～1: 30, and taking-up is dried, in 90～100 ℃ of oven dry;

2. batch mixing and hot-forming: the weak point of 100 ℃ of oven dry is cut 10～185 parts of sisal fiber raw materials mix for 100 parts with phenolic resin glue, in 70～80 ℃ of oven dry remove desolvate after, put into and be preheated to 110～120 ℃ metal die, continue to be heated to 150～160 ℃, hot pressing 10 minutes, pressure are 2.0～40MPa, and mould is cooled to below 70 ℃ and moves back mould, obtain short sisal fibers and strengthen phenolic resin composite, the fibre weight percentage composition in the composite is controlled at 10～65%.

3, a kind of preparation method of sisal fibre-resin base composite material is characterized in that technical process is:

1. the preparation of sisal fiber raw material: after raw material sisal fiber tow or the processing of woven cloth employing preprocess method, tow prescinds, and the weak point that obtains line density and be 10～70 Tekes, fibre length and be 3～10mm is cut sisal fiber or the sisal fiber woven cloth sisal fiber raw material as the preparation composite; Said preprocess method is one of following method:

A. seasoning: the raw material sisal fiber is put into 100 ℃ of baking ovens dry;

B. heat treating process: the raw material sisal fiber is put into 110～180 ℃ of baking ovens dried by the fire 1～6 hour;

C. alkali treatment method: the raw material sisal fiber is soaked in 1～5% the sodium hydroxide solution, bath raio is 1: 15～1: 30, ℃ handled 1～6 hour in room temperature to 80, then with the running water flushing to neutral, in 90～100 ℃ of oven dry;

D. acetylation facture: the raw material sisal fiber was soaked 1～10 minute with 18% sodium hydroxide solution, and then with 1～5% sulfuric acid solution neutralization, with 40～50% acetic acid processing 1～10 minute, bath raio was 1: 15～1: 30 again;

E. silane treatment method: will handle the sisal fiber raw material soaking that obtains in 1～10% KH-550 silane ethanolic solution 1～30 minute through the alkali treatment method, bath raio is 1: 15～1: 30, and taking-up is dried, in 90～100 ℃ of oven dry;

2. batch mixing and hot-forming: phenolic resin glue is coated on the sisal fiber cloth raw material two sides of 100 ℃ of oven dry, removed in 70～80 ℃ of oven dry and desolvate, three layers of the sisal fiber cloth of gluing are superimposed together by equidirectional then, are placed on

Hot pressing is 10 minutes on 155 ℃ the hydraulic press, and pressure is 20～40MPa, and release obtains sisal fiber cloth enhancing phenolic resins laminar composite after moving back mould, and the fibre weight percentage composition in the composite is controlled at 35～65%.

4, a kind of preparation method of sisal fibre-resin base composite material is characterized in that technical process is:

1. the preparation of sisal fiber raw material: after raw material sisal fiber tow or the processing of woven cloth employing preprocess method, tow prescinds, and the weak point that obtains line density and be 10～70 Tekes, fibre length and be 3～10mm is cut sisal fiber or the sisal fiber woven cloth sisal fiber raw material as the preparation composite; Said preprocess method is one of following method:

A. seasoning: the raw material sisal fiber is put into 100 ℃ of baking ovens dry;

B. heat treating process: the raw material sisal fiber is put into 110～180 ℃ of baking ovens dried by the fire 1～6 hour;

C. alkali treatment method: the raw material sisal fiber is soaked in 1～5% the sodium hydroxide solution, bath raio is 1: 15～1: 30, ℃ handled 1～6 hour in room temperature to 80, then with the running water flushing to neutral, in 90～100 ℃ of oven dry;

D. acetylation facture: the raw material sisal fiber was soaked 1～10 minute with 18% sodium hydroxide solution, and then with 1～5% sulfuric acid solution neutralization, with 40～50% acetic acid processing 1～10 minute, bath raio was 1: 15～1: 30 again;

E. silane treatment method: will handle the sisal fiber raw material soaking that obtains in 1～10% KH-550 silane ethanolic solution 1～30 minute through the alkali treatment method, bath raio is 1: 15～1: 30, and taking-up is dried, in 90～100 ℃ of oven dry;

2. batch mixing and hot-forming: the weak point of 100 ℃ of oven dry is cut 10～185 parts of sisal fiber raw materials and 100 parts of E-51 epoxy resin and 20～25 part 593 ^#Curing agent mixes, put into and be preheated to 55～65 ℃ metal die, constant temperature 10～15 minutes, treat that resin begins gel, be forced into 30～40MPa then, and constant temperature and pressure 2 hours, release was handled 2 hours in 80 ℃ after moving back mould, obtain short sisal fibers reinforced epoxy composite, the fibre weight percentage composition in the composite is controlled at 10～65%.