CN113861710B

CN113861710B - Antibacterial raw material powder, antibacterial wood-plastic composite material and preparation method thereof

Info

Publication number: CN113861710B
Application number: CN202111019294.9A
Authority: CN
Inventors: 邹智挥; 乔宗伟; 杨涛; 吴津田; 温浩宇; 高灵强; 胡雪菲; 廖斌; 安明哲; 苏建; 陈爽; 曲昌镭; 邹智元; 涂廉婕; 马振禄; 赵文彬; 陈治均; 王若尧; 易佳; 陈彬艺
Original assignee: Sichuan University of Science and Engineering; Wuliangye Yibin Co Ltd
Current assignee: Sichuan University of Science and Engineering; Wuliangye Yibin Co Ltd
Priority date: 2021-09-01
Filing date: 2021-09-01
Publication date: 2023-06-02
Anticipated expiration: 2041-09-01
Also published as: CN113861710A; TW202311412A

Abstract

An antibacterial raw material powder comprises 50% -99% of plant fiber raw material powder and 1% -50% of shell powder after high-temperature calcination; the plant fiber raw material is any one of vinasse, straw or rice husk, and the percentage is the mass ratio. An antibacterial wood-plastic composite material comprises 10% -50% of antibacterial raw material powder and 50% -90% of high polymer material, wherein the high polymer material is any one of polyolefin, polyester, biodegradable high polymer material and polyvinyl chloride, and the percentages are mass ratios. The invention also discloses a preparation method of the antibacterial wood-plastic composite material. The invention has simple production process, low cost, uniform dispersion of antibacterial powder in polymer, good mechanical property and excellent antibacterial property. The process is suitable for mass production, is easy to industrialize, has high product value, and can solve the problems that vinasse is easy to generate peculiar smell, spoil and deteriorate, bacterial mould is bred and is not easy to store for a long time.

Description

Antibacterial raw material powder, antibacterial wood-plastic composite material and preparation method thereof

Technical Field

The invention belongs to the technical field of materials, relates to a sterilization additive technology, and in particular relates to an antibacterial raw material powder, an antibacterial wood-plastic composite material and a preparation method thereof.

Background

The wood plastic products have wide application range and can be used for outdoor floors, decorative wallboards, guardrail posts, plastic-wood pavilions, garden guardrails, tree pools, nursery fences, leisure benches, flower boxes and the like. But it reduces the application due to its antimicrobial, mold-resistant properties.

The related technology of antibacterial mildew-proof wood-plastic is not so much, for example, chinese patent invention patent No. 201510595811.5 discloses a PP-based antibacterial wood-plastic composite board and a preparation method thereof, which mainly uses ethyl vanillin compounds as antibacterial additives, has simple process, only mixes the antibacterial additives into the polypropylene wood-plastic material, and has limited improvement effect.

The Chinese patent with the patent number of 201711434426.8 uses dichloro octyl isothiazolinone as antiseptic and antibacterial agent and adds the PVC wood plastic material, and the antiseptic and antibacterial agent also has certain biological toxicity.

The Chinese patent with the patent number of 201811504892.3 discloses that nano titanium dioxide-nano silver composite antibacterial agent is sprayed on the surface of biomass fiber and is used as an antibacterial wood-plastic raw material. The process comprises the steps of preparing a titanium tetrachloride hydrochloric acid solution, adding ammonia water into the solution to form a titanium hydroxide colloid solution, and adding hydrogen peroxide and silver nitrate aqueous solution into the titanium hydroxide colloid solution to obtain the nano titanium dioxide-nano silver composite antibacterial agent. Further, the powder is sprayed on one or a mixture of a plurality of straw powder, wood scraps, bamboo powder or cotton hull powder. The Chinese patent with the patent number of 202010886423.3 also discloses a similar method, wherein plant fiber powder and silver salt are dispersed in water according to the mass ratio of 20:1-10:1, then silane coupling agent is added, and after uniform stirring, the mixture is adsorbed in a dark place and dried, so that silver-loaded plant fiber powder is obtained and then is used as filling of wood-plastic raw materials. The two kinds of the materials have the similarity, the process is complicated, the cost is high, and the nano silver has a report that the nano silver has certain biotoxicity.

In summary, most of the antibacterial wood-plastic materials in the prior art have certain disadvantages, such as complex process, certain biotoxicity of antibacterial bodies, high cost and the like.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention discloses antibacterial raw material powder, a wood-plastic composite material and a preparation method thereof.

The antibacterial raw material powder comprises 50% -99% of plant fiber raw material powder and 1% -50% of shell powder after high-temperature calcination; the plant fiber raw material is any one of vinasse, straw or rice husk, and the percentage is the mass ratio.

The invention also discloses an antibacterial wood-plastic composite material, which comprises 10% -50% of antibacterial raw material powder and 50% -90% of high polymer material, wherein the high polymer material is any one of polyolefin, polyester, biodegradable high polymer material and polyvinyl chloride, and the percentages are mass ratios.

The invention also discloses a preparation method of the antibacterial wood-plastic composite material, which comprises the following steps:

s1, cleaning and drying plant fiber raw materials;

s2, cleaning and drying the shells, and calcining at a high temperature;

s3, crushing and grinding the shells and the plant fiber raw materials together to uniformly disperse and mix the two materials together to form antibacterial raw material powder, and then mixing the antibacterial raw material powder with a filter screen with the same mesh range to ensure that the particle sizes of the antibacterial raw material powder are similar and uniformly distributed; the mass ratio of the shell powder to the plant fiber raw material is 1% -50% and 50% -99% respectively;

s4, mixing the high molecular compound and the antibacterial raw material powder obtained in the step S3 by using a double-screw granulator to prepare an antibacterial and mildew-proof wood-plastic composite material; the mass ratio of the high molecular compound to the antibacterial raw material powder is 50-90% and 10-50% respectively; the polymer material is any one of polyolefin, polyester, biodegradable polymer material and polyvinyl chloride.

Preferably, the biodegradable polymer material is any one of PLA, PBAT, PCL, PBS, TPS, PHA, PHB, PHBV.

Preferably, in the step S4, additives including a compatibilizer, a lubricant and an antioxidant are further added during the mixing.

Preferably, the additive and the compatilizer are selected from any one or a mixture of more of oxazoline type, anhydride type, carboxylic acid type, epoxy type, hydroxyl type, epoxy type reaction type, titanate type, silane type, imide type and isocyanate type, wherein the imide type is modified polyacrylate.

Preferably, in the step S3, the antibacterial raw material powder formed after mixing is further subjected to surface activation together.

Preferably, the surface activation in the step S3 is performed by using one or two of a silica gel coupling agent and a silane coupling agent.

The invention uses biological waste shell to be calcined at high temperature, and then is crushed, ground and sieved together with the washed and dried plant fiber raw materials such as vinasse, straw, rice husk and the like. Finally, the wood-plastic composite material is obtained by blending the wood-plastic composite material with a high polymer material, and the wood-plastic composite material has the advantages of simple production process, low cost, uniform dispersion of antibacterial powder in the high polymer, good mechanical property and excellent antibacterial property. The process is suitable for mass production, is easy to industrialize, has high product value, and can solve the problems that the vinasse is easy to produce peculiar smell, bacteria, mould and the like are easy to breed, and the vinasse is difficult to store for a long time.

Detailed Description

The following describes the present invention in further detail.

The present invention will be described in further detail with reference to the following specific embodiments in order to make the objects, technical solutions and advantages of the present invention more apparent, but it should not be construed that the scope of the above subject matter of the present invention is limited to only the following examples. Various substitutions and alterations are made by those skilled in the art without departing from the spirit and scope of the invention.

The invention discloses antibacterial raw material powder, which comprises 50% -99% of plant fiber raw material powder and 1% -50% of shell powder after high-temperature calcination; the plant fiber raw material is any one of vinasse, straw or rice husk, and the percentage is the mass ratio.

The antibacterial wood-plastic composite material comprises 10% -50% of antibacterial raw material powder and 50% -90% of high polymer material, wherein the high polymer material is any one of polyolefin, polyester, biodegradable high polymer material and polyvinyl chloride, and the percentages are in mass ratio.

The preparation method of the antibacterial wood-plastic composite material comprises the following steps:

s1, cleaning and drying plant fiber raw materials;

s2, cleaning and drying the shells, and calcining at a high temperature;

when the filter screen is screened, a double filter screen can be adopted for screening, the mesh numbers of the double filter screens are different, for example, A1 and A2 are respectively, wherein A1 is larger than A2, and after the double filter screen passes through the filter screen, the particle size is larger than that of the A2 filter screen but smaller than that of the A1 filter screen, and the mesh number ranges from A1 to A2.

For example, a 600 mesh and 1000 mesh screen is used, and the particle size obtained is in the range between the 1000 mesh screen and the 600 mesh screen.

In the step S3, the mixed antibacterial raw material powder is subjected to surface activation together with different polymers, and is needed or not needed. The surface activation can be performed by adopting one or a mixture of two of a silica gel coupling agent and a silane coupling agent.

In the invention, the shell powder calcined at high temperature is taken as a main antibacterial component, and is mixed with the raw materials taking plant fibers as main components, such as vinasse, straw, rice husk and the like, and the shell powder or the plant fibers can play a role in reinforcing high polymers and improving mechanical strength under the condition that the compatibility of the compatilizer is improved, and the compatilizer is uniformly dispersed without agglomeration.

The invention has the positive effects that:

in the invention, the vinasse is extremely difficult to clean completely, a certain peculiar smell can be generated, and the vinasse can be adsorbed and reduced after being mixed with calcined shells, crushed and ground. So that the distillers' grains wood-plastic product has no peculiar smell and emits a natural fragrance.

In the invention, the calcined shell powder is used as an antibacterial component, and the addition of the vinasse powder or the antibacterial straw powder can improve the mechanical strength such as tensile strength, impact resistance and the like of the polymer.

In the invention, the antibacterial vinasse powder or the antibacterial straw powder can solve the problems that vinasse or straw is easy to absorb water, mildew and bacteria are bred, and can be stored for a long time.

In the invention, the antibacterial vinasse powder or the antibacterial straw powder can overcome the defect that the common antibacterial powder has biotoxicity.

In the invention, the antibacterial vinasse powder or the antibacterial straw powder can improve the defect of poor dispersibility of plant fibers and antibacterial powder.

In the specification of the invention, unless specified otherwise, the percentages represent the percentage of the total mass of the antibacterial raw material powder and the polymer material.

Example 1:

the preparation method of the antibacterial raw material powder comprises the following steps:

(1) Preparation of vinasse recovery raw materials: collecting the waste grains after the white spirit fermentation in the brewing factory, cleaning, drying the waste grains in an oven at 125 ℃ for 8 hours,

(2) The oyster shell is recovered, washed and dried, and calcined at the high temperature of 1000 ℃;

(3) Then, the distilled grain and the calcined oyster shell are crushed and ground together, so that the two materials are uniformly dispersed and mixed together to form antibacterial raw material powder, and a filter screen with the mesh number of 600-1000 is used for ensuring that the particle sizes of the antibacterial raw material powder are similar and the antibacterial raw material powder is uniformly distributed; finally, the antibacterial raw material powder is prepared by mixing, and the ratio of the vinasse to the calcined oyster shell is 49:1.

(4) Preparing an antibacterial wood-plastic composite material: putting 25% of antibacterial raw material powder and PLA into an extruder, adding a compatilizer silane coupling agent accounting for 1% of the total mass of the antibacterial raw material powder and PLA, 0.3% of lubricant paraffin and 0.4% of antioxidant triaryl phosphite ester by weight, mixing the antibacterial raw material powder and the PLA together by a double-screw extruder, and granulating by a supercooling water tank after mixing and extruding at 180-195 ℃ to obtain the antibacterial wood-plastic composite material.

Example 2:

the difference from example 1 is that the ratio of distillers grains to calcined oyster shell is 1:1.

example 3:

the difference from example 1 is that the sieving particle size of the distillers grains and the calcined oyster shell is between 100 and 300 meshes;

example 4:

the difference from example 1 is that the distillers grains are replaced with straw.

Comparative example 1:

grinding 24.5% of distilled grain, 0.5% of calcined oyster shell powder respectively, sieving with 600-1000 mesh sieve respectively, placing distilled grain, calcined oyster shell powder and 75% of PLA into an extruder, adding 1% by weight of compatilizer silane coupling agent, 0.3% by weight of lubricant paraffin and 0.4% by weight of antioxidant triaryl phosphite ester based on the total mass of distilled grain, oyster shell powder and PLA, mixing by a double-screw extruder, processing at 180-195 ℃ and granulating by a supercooled water tank after mixing, processing and extrusion to obtain the antibacterial wood-plastic composite material.

Comparative example 2:

the difference from comparative example 1 is distillers grains, and the mass ratio of calcined oyster shell powder to PLA is 12.5%, 12.5% and 7.5%, respectively.

Comparative example 3:

the difference from comparative example 1 is that the grain size of the distilled grain and the calcined oyster shell is 100-300 mesh.

Comparative example 4:

the difference from comparative example 1 is that the distillers grains therein were replaced with straw.

Table one gives the tensile strength and antibacterial rate test data for the composites prepared in examples 1 to 4 and comparative examples 1 to 4;

wherein the tensile strength test method is performed according to ASTM-D638.

The test method of the antibacterial rate is carried out according to ASTM E2149-01 standard.

List one

Sample of	Tensile Strength (MPa)	Antibacterial efficiency (%)
			PLA	45.3	0
Example 1	54.9	98.4
			Comparative example 1	43.4	96.1
Example 2	62.5	99.9
			Comparative example 2	47.2	99.6
Example 3	48.1	91.7
			Comparative example 3	39.6	85.2
Example 4	52.7	98.8
			Comparative example 4	42.9	95.6

As can be seen from Table one, the pure PLA has no antibacterial effect, and all the composite materials have certain antibacterial property because of containing calcined oyster shell powder. And it can be observed that all of examples 1, 2, 3, and 4 were higher in antibacterial effect and tensile strength than comparative examples 1, 2, 3, and 4, respectively. This is because the antibacterial lees or straw powder of examples 1 to 4 is co-crushed, ground and sieved with the calcined oyster shell, and the two different powders are sufficiently and uniformly mixed in the co-crushing and grinding because of the similar particle sizes, so that the agglomeration phenomenon of single components is reduced, and the comparative example is that the maximum and minimum particle sizes are different because of the separate sieving without the co-crushing and co-sieving, and if sieving with a 100-300 mesh sieve, the calcined oyster shell particle size is likely to be nearly 100 mesh, and the lees is likely to be extremely different from 300 mesh; or the calcined oyster shell is mostly close to 300 meshes, and the vinasse is mostly close to 100 meshes, and the like, so that the particle size difference is larger; in addition, the comparative example needs to mix the calcined oyster shell and the distillers' grains uniformly before melting and mixing with the polymer, and if the mixture is not sufficiently uniform, or if the mixture is not mixed and processed directly, the final composite material is easy to form partial agglomeration or defect of the product is caused, and the two reasons are the reasons for reducing the mechanical properties.

It can be seen that the uniform powder, when co-blended with PLA in a mixing mill, can achieve a fully dispersed composite and further achieve reinforcement of PLA.

Example 5:

the difference from experimental example 1 is that step (4) is as follows:

25% of antibacterial raw material powder is subjected to surface activation for 30 minutes at 110 ℃ through a silane coupling agent, the silane coupling agent accounts for 1% of the total amount of the antibacterial raw material powder, the antibacterial raw material powder and 75% of PP are placed into an extruder, and a compatilizer acrylic grafted polypropylene accounting for 5% by weight of the total mass of the PP and the antibacterial raw material powder, 1% by weight of lubricant paraffin and 0.4% by weight of antioxidant are additionally added, wherein 168 = 0.3% by weight of antioxidant and 1010 = 0.1% by weight of antioxidant are mixed together through a double-screw extruder, the processing temperature is 180-190 ℃, and the mixture is subjected to blending processing and extrusion, and then is subjected to supercooling water tank granulation, so that the antibacterial wood plastic PP composite material is prepared.

Example 6:

the difference from example 5 is that the mass ratio of distillers grains to calcined oyster shell is 1:1.

Example 7:

the difference from example 5 is that the grain size of the distillers grains and the calcined oyster shell is between 100 and 300 mesh.

Example 8:

the difference from example 5 is that the distillers grains are replaced with straw.

Comparative example 5:

according to 24.5% of vinasse, 0.5% of calcined oyster shell powder, respectively crushing and grinding, respectively sieving with 600-1000 mesh sieve, respectively carrying out surface activation at 110 ℃ for 30 minutes by using silane coupling agents, then placing the vinasse, the calcined oyster shell powder and 75% of PP (polypropylene) in an extruder, and adding 1% by weight of compatilizer acrylic grafted polypropylene, 0.3% by weight of lubricant paraffin and 0.4% by weight of antioxidant into the extruder, wherein 168 = 0.3% by weight of antioxidant and 1010 = 0.1% by weight of antioxidant are mixed together by using a double screw extruder, the processing temperature is 180-195 ℃, and granulating by using a supercooled water tank after mixing, processing and extrusion to obtain the antibacterial wood-plastic composite material.

Comparative example 6:

the difference from comparative example 5 is that distillers grains 12.5%, and calcined oyster shell powder 12.5% and 75% pla were placed in an extruder.

Comparative example 7:

the difference from comparative example 5 is that the grain size of the distilled grain and the calcined oyster shell is 100-300 mesh.

Comparative example 8:

the difference from comparative example 5 is that the distillers grains therein were replaced with straw.

Table two gives the tensile strength and antibacterial rate test data for the composites prepared in examples 5 to 8 and comparative examples 5 to 8;

watch II

Sample of	Tensile Strength (MPa)	Antibacterial efficiency (%)
			PP	23.2	0
Example 5	28.7	97.6
			Comparative example 5	22.1	92.4
Example 6	30.4	99.9
			Comparative example 6	25.8	99.2
Example 7	24.1	90.9
			Comparative example 7	21.0	83.7
Example 8	27.6	98.2
			Comparative example 8	22.4	94.8

As can be seen from Table II, the pure PP has no antibacterial effect, and all the composite materials have certain antibacterial property because of containing calcined oyster shell powder. And it can be observed that all of examples 5, 6, 7, 8 are higher in antibacterial effect and tensile strength than comparative examples 5, 6, 7, 8, respectively.

Example 9:

the difference from experimental example 1 is that step (4) is as follows:

putting 25% of antibacterial raw material powder and 75% of PBAT into an extruder, adding 0.8wt% of compatilizer silane coupling agent, 0.6wt% of lubricant paraffin and 0.4wt% of antioxidant which are the total mass of the PBAT and the antibacterial raw material powder, wherein 168-0.3wt% of antioxidant and 1010-0.1wt% of antioxidant are mixed together by a double-screw extruder, and granulating by a supercooling water tank after mixing, processing and extrusion at 170-185 ℃ to obtain the antibacterial wood-plastic PBAT composite material.

Example 10:

the difference from example 5 is that the ratio of distillers grains to calcined oyster shell is 1:1.

Example 11:

the difference from example 5 is that the PBAT is changed to PBS.

Example 12:

the difference from example 5 is that the PBAT is changed to PET.

Example 13:

the difference from example 5 is that the PBAT is changed to PVC, the compatilizer and its content are changed to PVC-g-AA ( pieces of acrylic acid polyvinyl chloride) and 5%.

Comparative example 9:

grinding 24.5% of distilled grains, 0.5% of calcined oyster shell powder respectively, sieving with 600-1000 mesh sieve respectively, placing distilled grains, calcined oyster shell powder and 75% of PBAT (poly (butylene terephthalate)) into an extruder, adding 0.8wt% of compatilizer silane coupling agent, 0.6wt% of lubricant paraffin and 0.4wt% of antioxidant, wherein the antioxidant 168=0.2wi% and the antioxidant 1010=0.2wi% into the extruder, mixing the materials by a double screw extruder at the processing temperature of 170-185 ℃, and granulating by a supercooled water tank after mixing, extruding and granulating to obtain the antibacterial wood-plastic composite material.

Comparative example 10:

the difference from comparative example 9 is that the ratio of distillers grains to calcined oyster shell is 1:1.

Comparative example 11:

the difference from comparative example 9 is that the PBAT was changed to PBS.

Comparative example 12:

the difference from comparative example 9 is that the PBAT was changed to PET.

Comparative example 13:

the difference from comparative example 9 is that PBAT was changed to PVC, and the compatibilizing agent and the content thereof were changed to PVC-g-AA ( -branched polyvinyl chloride acrylate) and 5%.

Table III shows the tensile strength and antibacterial rate test data for the composite materials prepared in examples 9 to 13 and comparative examples 9 to 13

Watch III

Sample of	Tensile Strength (MPa)	Antibacterial efficiency (%)
			Example 9	26.5	98.1
Comparative example 9	24.1	93.5
			Example 10	31.2	98.6
Comparative example 10	25.9	95.5
			Example 11	25.2	94.4
Comparative example 11	22.7	89.4
			Example 12	21.9	95.1
Comparative example 12	18.6	91.8
			Example 13	43.5	98.7
Comparative example 13	38.1	96.3

From table three, it was observed that all of examples 9, 10, 11, 12, 13 were higher in antibacterial effect and tensile strength than comparative examples 9, 10, 11, 12, 13, respectively.

The foregoing description of the preferred embodiments of the present invention is not obvious contradiction or on the premise of a certain preferred embodiment, but all the preferred embodiments can be used in any overlapped combination, and the embodiments and specific parameters in the embodiments are only for clearly describing the invention verification process of the inventor, and are not intended to limit the scope of the invention, and the scope of the invention is still subject to the claims, and all equivalent structural changes made by applying the content of the description of the present invention are included in the scope of the invention.

Claims

1. The preparation method of the antibacterial wood-plastic composite material is characterized by comprising the following steps of:

s1, cleaning and drying plant fiber raw materials;

s2, cleaning and drying the shells, and calcining at a high temperature;

s3, crushing and grinding the shell powder and the plant fiber raw material after high-temperature calcination together, uniformly dispersing and mixing the two materials to form antibacterial raw material powder, and then uniformly mixing the antibacterial raw material powder with a filter screen with the same mesh range to obtain antibacterial raw material powder, wherein the particle sizes of the antibacterial raw material powder are similar;

s4, mixing the high polymer material and the antibacterial raw material powder obtained in the step S3 by using a double-screw granulator to prepare an antibacterial and mildew-proof wood-plastic composite material;

the mass fractions of the polymer material and the antibacterial raw material powder are respectively 50% -90% and 10% -50%; the high polymer material is any one of polyolefin, polyester and biodegradable high polymer plastic;

in the step S4, additives including compatilizer, lubricant and antioxidant are added during mixing;

the antibacterial raw material powder comprises 50% -99% of plant fiber raw material powder and 1% -50% of shell powder after high-temperature calcination; the plant fiber raw material is any one of vinasse, straw or rice husk, and the percentage is the mass ratio;

the compatilizer is a silane coupling agent.

2. The method of claim 1, wherein the biodegradable polymer plastic is any one of PLA, PBAT, PCL, PBS, TPS, PHA, PHB, PHBV.