CN104804452A - Method of preparing polyvinyl wood-plastic composite with cotton stalks - Google Patents

Abstract

The invention discloses a method of preparing polyvinyl wood-plastic composite with cotton stalks. The method comprises the following steps: soaking cotton stalks in a sodium hydroxide aqueous solution to alkalify the cotton stalks, washing the alkalified cotton stalks with distilled water, drying the washed cotton stalks, and smashing the dried cotton stalks to obtain cotton stalk powder; weighing and taking raw materials according to the mass ratio of cotton stalk powder to medium density polyethylene to azobisisobutyronitrile to dibutyltin oxide to silicone oil to chlorinated paraffin to dibasic lead phthalate being (20-60):(20-50):(0.05-1.8):(0.02-1.5):(15-20):(1-7):(0.5-4.0); stirring the mixed raw materials at a high speed to obtain mixed materials; performing reactive extrusion in a double-screw extruder to obtain extruded materials; pressing a mold containing the extruded materials on a press vulcanizer to obtain the polyvinyl wood-plastic composite. The method is easy to operate, and the prepared polyvinyl wood-plastic composite is nontoxic, environment-friendly, good in comprehensive performance and wide in application prospect.

Description

A kind of method utilizing cotton stem to prepare polyethylene based wood-plastic composite material

Technical field

The invention belongs to wood plastic composite preparing technical field, particularly a kind of method utilizing cotton stem to prepare polyethylene based wood-plastic composite material.

Background technology

Containing wood powder and thermoplastic cement raw material in wood plastic composite, thermoplastic cement raw material wherein can adopt the dead meal of industry or life, and cotton stem is a kind of important agricultural wastes, and its amount is large, can do the wood powder of wood plastic composite after pulverizing.From the angle of raw materials for production, lignin plastics goods slow down and eliminate the public hazards pollution of plastic refuse, also eliminate cotton stem and pile up and burn the pollution brought to environment.Matrix material has had the advantage of timber and plastics concurrently simultaneously: 1. good processing characteristics.Wood plastic composite includes plastics and fiber, therefore, has the processing characteristics that same timber is similar, can saw, can follow closely, can dig, and use carpenter's utensil to complete, and nail-holding ability is obviously better than other synthetic materialss.Mechanical property is better than wood materials.Nail-holding ability is generally 3 times of timber, is 5 times of shaving board.2. good strength property.Wood plastic composite includes plastics, thus has good Young's modulus.In addition, due to including fiber and through fully mixing with plastics, thus there is the resistance to compression suitable with hardwood, the physical and mechanical properties such as counter-bending, and its wearing quality is obviously better than normal wood material.Surface hardness is high, is generally 2 ~ 5 times of timber.3. there is water-fast, corrosion resistant performance, long service life.Wood-plastic material and products thereof, can anti-strong acid-base, water-fast, corrosion-resistant compared with timber, and not bacterial growth, is not easily damaged by worms, not long fungi.Long service life, can reach more than 50 years.4. excellent adjustable performance.By auxiliary agent, the changes such as plastics can be polymerized, foam, solidify, modification, thus the characteristic such as density, intensity changing Wood-plastic material, can also reach anti-aging, anti-electrostatic, the particular requirement such as fire-retardant.

Because wood plastic composite has so many performance, just decide it will be widely used.1. construction industry.The floor of making by Wood Fiber Composites than superior many in low wood fibre board performance at present, not breathing, waterproof, surface aesthetic.If meet material for multilayer coextrusion section bar, internal layer adopts reclaimed materials, and outer employing virgin material, the every mechanical property of the goods made can compare favourably with hardwood products.2. the application of automobile industry.In recent years, Wood plastic boards, with its rational price, superior performance, is applied and is increased in automobile decoration material, as automobile door-plate, after put thing case, luggage case sidewall, seat plate etc.3. other industry.Except traditional industry, the Application Areas of matrix material constantly expands, started at present apply as pallet, flowerpot, handle for tool, office appliance, attack the engine components such as fast highway route marker, acoustic board and audio amplifier.

As everyone knows, polyethylene is one of four large general-purpose plastics in macromolecular material, and its consumption accounts for 60%.Along with the continuous expansion of polyethylene consumption market, the continuous variation of consumption kind, its poly waste amount is also in continuous increase.At present, the waste of the upper recoverable of annual society of China about has 1Mt, and what reality utilized about has 0.2Mt, 0.8Mt is also had to fail to be recycled, major part waste is disposed with land-fill method, so not only causes secondary pollution, also result in the profligacy of material.Along with science and technology, constantly progress and demand for energy constantly increase, how sooner, the recycling work relationship of carrying out waste better the rich and powerful of country and progress, and one of the recycling solving polyethylene waste important content during to be all waste thing recycle.

Summary of the invention

The object of this invention is to provide a kind of method utilizing cotton stem to prepare polyethylene based wood-plastic composite material.

Concrete steps are:

(1) cotton stem being immersed in mass percent concentration is alkalinisation treatment 2 ~ 3 hours in the aqueous sodium hydroxide solution of 15 ~ 25%, and alkalization temperature is 30 ~ 40 DEG C, obtained alkalinisation treatment cotton stem.

(2) alkalinisation treatment cotton stem distilled water wash step (1) obtained 3 ~ 4 times, the alkali on removing bar and other impurity, then drying treatment, through mechanical disintegration, obtained particle diameter is 50 ~ 70 object cotton stem powder.

(3) raw material is taken according to following mass ratio, the cotton stem powder that step (2) is obtained: medium-density polyethylene: azo-bis-isobutyl cyanide: Dibutyltin oxide: silicone oil: clorafin: Dythal=20 ~ 60:20 ~ 50:0.05 ~ 1.8:0.02 ~ 1.5:15 ~ 20:1 ~ 7:0.5 ~ 4.0, raw material is mixed on homogenizer, the rotating speed of homogenizer is 4000 ~ 8000 revs/min, obtained mixture.

(4) by mixture reactive extrursion in twin screw extruder that step (3) is obtained, extruder temperature is set to 120 ~ 160 DEG C, and rotating speed is 400 ~ 600 revs/min, and the residence time of material in screw rod is 4 ~ 8 minutes, obtained extruded material.

(5) vulcanizing press is heated, the temperature arranging top plate is 190 DEG C, the temperature of lower bolster is 190 DEG C, treat that temperature rises to the temperature of setting, constant temperature 15 minutes, mould to be placed between two templates preheating 30 minutes, then mould is opened, the extruded material that step (4) is obtained is put into the die cavity of mould, to cover in template that mould puts it to vulcanizing press preheating again 10 minutes, carry out first time exhaust, mold pressing 10 minutes under 8 ~ 10Mpa after exhaust, carry out second time exhaust again, then mold pressing 10 minutes under 8 ~ 10Mpa, cool, treat that temperature drops to 35 DEG C, pressure release, take out mould, and open, the plate be pressed into is taken out, naturally cooling under room temperature, i.e. obtained polyethylene based wood-plastic composite material.

The inventive method is simple to operate, utilization of waste material, is easy to large-scale promotion, and obtained polyethylene based wood-plastic composite material asepsis environment-protecting, high comprehensive performance, easily processes, and can substitute traditional timber, have a extensive future.

Embodiment

embodiment:

(1) cotton stem being immersed in mass percent concentration is alkalinisation treatment 2.5 hours in the aqueous sodium hydroxide solution of 20%, and alkalization temperature is 35 DEG C, obtained alkalinisation treatment cotton stem.

(2) alkalinisation treatment cotton stem distilled water wash step (1) obtained 3 times, the alkali on removing bar and other impurity, then drying treatment, through mechanical disintegration, obtained particle diameter is 60 object cotton stem powder.

(3) raw material is taken according to following mass ratio, the cotton stem powder that step (2) is obtained: medium-density polyethylene: azo-bis-isobutyl cyanide: Dibutyltin oxide: silicone oil: clorafin: Dythal=40:35:0.9:0.78:18:4:2.4, raw material is mixed on homogenizer, the rotating speed of homogenizer is 6000 revs/min, obtained mixture.

(4) by mixture reactive extrursion in twin screw extruder that step (3) is obtained, extruder temperature is set to 140 DEG C, and rotating speed is 500 revs/min, and the residence time of material in screw rod is 6 minutes, obtained extruded material.

(5) vulcanizing press is heated, the temperature arranging top plate is 190 DEG C, the temperature of lower bolster is 190 DEG C, treat that temperature rises to the temperature of setting, constant temperature 15 minutes, mould to be placed between two templates preheating 30 minutes, then mould is opened, the extruded material that step (4) is obtained is put into the die cavity of mould, to cover in template that mould puts it to vulcanizing press preheating again 10 minutes, carry out first time exhaust, mold pressing 10 minutes under 9Mpa after exhaust, carry out second time exhaust again, then mold pressing 10 minutes under 9Mpa, cool, treat that temperature drops to 35 DEG C, pressure release, take out mould, and open, the plate be pressed into is taken out, naturally cooling under room temperature, i.e. obtained polyethylene based wood-plastic composite material.

The shock strength of the polyethylene based wood-plastic composite material that the present embodiment obtains is 5.211 KJ/m ², tensile strength is 51.437 MPa, flexural strength 43.862 KJ/m ², water-intake rate is 3.021 %, all comparatively excellent.

Claims (1)

1. utilize cotton stem to prepare a method for polyethylene based wood-plastic composite material, it is characterized in that concrete steps are:

(1) cotton stem being immersed in mass percent concentration is alkalinisation treatment 2 ~ 3 hours in the aqueous sodium hydroxide solution of 15 ~ 25%, and alkalization temperature is 30 ~ 40 DEG C, obtained alkalinisation treatment cotton stem;

(2) alkalinisation treatment cotton stem distilled water wash step (1) obtained 3 ~ 4 times, the alkali on removing bar and other impurity, then drying treatment, through mechanical disintegration, obtained particle diameter is 50 ~ 70 object cotton stem powder;

(3) raw material is taken according to following mass ratio, the cotton stem powder that step (2) is obtained: medium-density polyethylene: azo-bis-isobutyl cyanide: Dibutyltin oxide: silicone oil: clorafin: Dythal=20 ~ 60:20 ~ 50:0.05 ~ 1.8:0.02 ~ 1.5:15 ~ 20:1 ~ 7:0.5 ~ 4.0, raw material is mixed on homogenizer, the rotating speed of homogenizer is 4000 ~ 8000 revs/min, obtained mixture;

(4) by mixture reactive extrursion in twin screw extruder that step (3) is obtained, extruder temperature is set to 120 ~ 160 DEG C, and rotating speed is 400 ~ 600 revs/min, and the residence time of material in screw rod is 4 ~ 8 minutes, obtained extruded material;

(5) vulcanizing press is heated, the temperature arranging top plate is 190 DEG C, the temperature of lower bolster is 190 DEG C, treat that temperature rises to the temperature of setting, constant temperature 15 minutes, mould to be placed between two templates preheating 30 minutes, then mould is opened, the extruded material that step (4) is obtained is put into the die cavity of mould, to cover in template that mould puts it to vulcanizing press preheating again 10 minutes, carry out first time exhaust, mold pressing 10 minutes under 8 ~ 10Mpa after exhaust, carry out second time exhaust again, then mold pressing 10 minutes under 8 ~ 10Mpa, cool, treat that temperature drops to 35 DEG C, pressure release, take out mould, and open, the plate be pressed into is taken out, naturally cooling under room temperature, i.e. obtained polyethylene based wood-plastic composite material.