WO2023124710A1

WO2023124710A1 - Polypropylene material and preparation method therefor

Info

Publication number: WO2023124710A1
Application number: PCT/CN2022/135171
Authority: WO
Inventors: 张栋玮; 陈平绪; 叶南飚; 李晟; 陶四平
Original assignee: 天津金发新材料有限公司
Priority date: 2021-12-31
Filing date: 2022-11-29
Publication date: 2023-07-06
Also published as: CN114196115B; CN114196115A

Abstract

The present invention belongs to the technical field of polypropylene plastics. Disclosed are a polypropylene material and a preparation method therefor, in order to overcome the technical problems of poor compatibility and unbalanced mechanical properties of an existing plant fiber and polypropylene composite material in the prior art. The polypropylene material in the present invention comprises a polypropylene resin and modified plant fibers, wherein the modified plant fibers comprise plant fibers, a POE elastomer, a siloxane coupling agent and an organic peroxide. The present invention further provides a preparation method for a polypropylene material, and the polypropylene material is used as modified polypropylene materials for civil construction, household appliances and vehicles. The polypropylene material in the present invention, as a composite material, has excellent plant fiber-polypropylene compatibility, high rigidity and toughness, balanced mechanical properties and excellent appearance.

Description

A kind of polypropylene material and preparation method thereof

technical field

The invention relates to the technical field of polymer materials, in particular to a polypropylene material and a preparation method thereof.

Background technique

Natural plant fiber composite material is a kind of composite material with natural plant fiber as reinforcement material and resin as matrix. Natural plant fiber has the advantages of cheap, recyclable, degradable, renewable, etc., and has the strength and stiffness of ordinary fibers, and has a small specific gravity, high specific strength and specific stiffness. Composite materials based on natural plant fibers also have excellent properties, such as low price, low density, good strength, and excellent thermal performance.

However, since the plant fiber has strong hydrophilicity, the compatibility between the plant fiber and the hydrophobic polypropylene resin is very poor. As a result, when plant fibers are used to reinforce polypropylene resin to prepare composite materials, it is easy to form voids and defects on the composite interface, resulting in poor mechanical properties of composite materials. In particular, when the content of plant fibers is high, the composites show obvious brittleness, and it is difficult to obtain composites with excellent rigidity. In the prior art, natural fibers are processed to obtain natural fibers with rough surfaces, and then polar monomer graft polymers are used as compatibilizers to improve the interfacial bonding force between natural fibers and polypropylene. Although this technology can improve Natural fibers reinforce the rigidity of polypropylene composites, but the interaction between the grafted polymers of polar monomers, natural fibers and polypropylene only depends on van der Waals force, and the toughness of the material cannot be guaranteed.

Therefore, there is an urgent need to develop a polypropylene material with good interfacial compatibility between plant fibers and polypropylene and good mechanical properties and a preparation method thereof.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a polypropylene material and its preparation method, in order to overcome the technical problems of poor compatibility and unbalanced mechanical properties of existing plant fibers and polypropylene composite materials.

In order to achieve the above object, the technical scheme that the present invention takes is as follows:

In the first aspect, the present invention provides a polypropylene material, comprising the following components in parts by weight: 50-90 parts of polypropylene resin, 10-50 parts of modified plant fiber;

Wherein, the modified plant fiber is made of the following raw materials in parts by weight: 50-80 parts of plant fiber, 20-50 parts of POE elastomer, 0.5-2 parts of siloxane coupling agent, organic peroxide 0.1～1 part;

The melt index of the polypropylene resin is 5-60g/10min, and the test conditions are: 230°C, 2.16kg;

The average length of the plant fibers is 1-30mm;

The siloxane coupling agent is one or more of amino siloxane coupling agents or epoxy siloxane coupling agents;

The organic peroxide is one or more of alkyl peroxides or acyl peroxides.

In the polypropylene material, some groups of organic peroxides are grafted on the surface of plant fibers through the peroxidation reaction of organic peroxides, while POE elastomers are oxidized to form free radicals, and plant fibers and POE elastomers form crosslinks. One end of the siloxane coupling agent has a silane group, the silane group is hydrolyzed to form silanol, and the silanol further chemically reacts with the hydroxyl group in the plant fiber to form a stable covalent bond and reduce the surface of the plant fiber. The number of hydroxyl groups; the other end of the siloxane coupling agent is a carbon functional group, which can react with the polypropylene resin or form a hydrogen bond, so that a crosslinked network is formed between the plant fiber and the polypropylene resin, thereby reducing the swelling of the plant fiber. Further improve the bonding stability between plant fiber and polypropylene resin, so that the modified plant fiber has better compatibility with polypropylene resin, and it is easier to disperse and be compatible after blending with polypropylene resin, thereby having Better and more balanced mechanical properties and surface appearance.

As a preferred embodiment of the polypropylene material of the present invention, the melt index of the polypropylene resin is 16-50 g/10 min, and the test conditions are: 230° C., 2.16 kg. The preferred polypropylene resin is more conducive to the uniform dispersion of plant fibers in the resin.

As a preferred embodiment of the polypropylene material in the present invention, the plant fiber is at least one of flax fiber, sisal fiber, hemp fiber, jute fiber, kenaf fiber, ramie fiber and bamboo fiber.

As a preferred embodiment of the polypropylene material of the present invention, the average length of the plant fibers is 2-10 mm.

As a preferred embodiment of the polypropylene material in the present invention, the POE elastomer is at least one of ethylene-octene copolymer and ethylene-butene copolymer.

As a preferred embodiment of the polypropylene material of the present invention, the organic peroxide is benzoyl peroxide, bis(tert-butylperoxyisopropyl)benzene, di-tert-butyl peroxide, decaperoxide At least one of diacyl and dicumyl peroxide.

As a preferred embodiment of the polypropylene material of the present invention, the siloxane coupling agent is γ-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane , γ-ureidopropyltriethoxysilane, β-(3,4 epoxycyclohexyl)-ethyltriethoxysilane at least one.

In a second aspect, the present invention provides a method for preparing the above-mentioned polypropylene material, comprising the following steps:

The polypropylene and the modified plant fiber are weighed and mixed according to the parts by weight, melted, extruded, granulated, and dried to obtain the obtained product.

Wherein, the preparation method of the modified plant fiber is: take the plant fiber, elastomer, siloxane coupling agent, and organic peroxide according to the weight parts and mix to obtain a premix; granulation, grading, cooling, extrusion granulation, and it is ready.

In the third aspect, the present invention applies the above-mentioned polypropylene material to polypropylene modified materials for civil engineering, household appliances and vehicles.

Compared with prior art, the beneficial effect of the present invention is:

In the polypropylene material of the invention, the compatibility between the plant fiber and the polypropylene composite material is good, the polypropylene material has good rigidity and toughness, balanced mechanical properties, and excellent appearance. It is suitable for polypropylene modified materials used in civil engineering, household appliances and vehicles.

Description of drawings

Figure 1 is a reference diagram of the first-class appearance floating fiber;

Figure 2 is a reference diagram of the second-level appearance floating fiber;

Figure 3 is a reference diagram of floating fiber with 3-level appearance;

Figure 4 is a reference diagram of level 4 appearance floating fiber;

Figure 5 is a reference diagram of the appearance of floating fibers of grade 5.

Detailed ways

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific examples. Those skilled in the art should understand that the specific embodiments described here are only used to explain the present invention, and are not intended to limit the present invention.

The test methods used in the examples, unless otherwise specified, are conventional methods; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial sources.

In the following examples, the flexural modulus is detected according to the standard "ISO 178:2001 Determination of Plastic Bending Properties"; the notched impact strength is detected with reference to the standard "ISO 180:2000 Determination of Plastic Izod Impact Strength"; the appearance grade is based on Floating fiber evaluation on the surface of the material, visual observation of the floating fiber condition on the surface, rating according to the whitening of the surface glass fiber, a total of 5 grades, the more * means the worse the floating fiber appearance, * (level 1) refer to Figure 1, ** (Level 2) refer to Figure 2, *** (Level 3) refer to Figure 3, **** (Level 4) refer to Figure 4, ***** (Level 5) refer to Figure 5.

The raw materials used in the following examples and comparative examples are described below, but are not limited to these materials:

Polypropylene resin 1: PP, EP548R, block copolymerized polypropylene, melt index is 30g/10min, purchased from Shell;

Polypropylene resin 2: PP, T30S, homopolypropylene, melt index is 3g/10min, purchased from Sinopec;

Polypropylene resin 3: PP, K9017, block copolymerized polypropylene, melt index is 16g/10min, purchased from Taihua;

Polypropylene resin 4: PP, BX3900, block copolymer polypropylene, melt index is 50g/10min, purchased from SK;

Polypropylene resin 5: PP, BX3920, block copolymerized polypropylene, melt index is 100g/10min, purchased from SK;

The melt mass flow rate of the above resin is tested under the condition of 230°C/2.16kg according to the standard ISO 1133:2005.

Plant fiber 1: jute fiber, the average fiber length is 2-10mm, purchased from Hedi Technology;

Plant fiber 2: sisal fiber, the average fiber length is 2-10 mm, purchased from Hedi Technology;

Plant fiber 3: bamboo fiber, the average fiber length is 2-10 mm, purchased from Hedi Technology;

Plant fiber 4: jute fiber, the average fiber length is 40-50 mm, purchased from Hedi Technology;

Plant fiber 5: jute fiber, the average fiber length is 0.1-0.5mm, purchased from Hedi Technology;

Elastomer 1: POE 7467, ethylene-butylene copolymer, available from Dow;

Elastomer 2: POE 8842, ethylene-octene copolymer, available from Dow;

Elastomer 3: SEBS 1657, hydrogenated styrene-butadiene block copolymer, purchased from Kraton, USA;

Coupling agent 1: γ-glycidyl etheroxypropyl trimethoxysilane (epoxy siloxane coupling agent), Z-6040, purchased from Dow Corning Corporation of the United States;

Coupling agent 2: 3-(2,3-glycidoxy)propyltrimethoxysilane (epoxy siloxane coupling agent), A-187, purchased from Momentive;

Coupling agent 3: γ-ureidopropyltriethoxysilane (amino siloxane coupling agent), A-1160, purchased from Momentive;

Coupling agent 4: bis(γ-triethoxysilylpropyl) tetrasulfide, Z-6940, purchased from Dow Corning, USA;

Organic peroxide 1: benzoyl peroxide, purchased from sigma-aldrich;

Organic peroxide 2: dicumyl peroxide, available from sigma-aldrich;

Organic peroxide 3: lauryl peroxide, purchased from sigma-aldrich;

Organic peroxide 4: Dicarbonate peroxydicarbonate (liquid, low in active oxygen), purchased from sigma-aldrich.

The composition of the modified plant fiber is shown in Table 1.

The preparation method of modified plant fiber is:

Weigh the plant fiber, elastomer, coupling agent, and organic peroxide according to the parts by weight in Table 1, and put them into a banbury mixer for 10 to 20 minutes of banburying, so that the plant fiber and the elastomer are fully mixed evenly to obtain a premix; The obtained premixed material is granulated by a single-screw extruder, classified, cooled, and the process of extrusion and granulation is repeated three times to obtain the modified plant fiber.

Table 1: Formulation composition (parts by weight) of different modified fibers

Continuation of Table 1: Formulations (parts by weight) of different modified fibers

The components of the polypropylene materials in Examples 1-12 and Comparative Examples 1-14 are shown in Table 2.

The preparation method of polypropylene material is:

Weigh the polypropylene and modified plant fibers according to the parts by weight in Table 2, add them into the high-speed mixer and mix them at high speed for 1 to 3 minutes, and mix evenly to obtain the premix; add the premix to the main feeding port of the twin-screw extruder , melt-extruded, granulated and dried to obtain polypropylene material.

Wherein, the conditions of the melting extrusion step are: the temperature of the first zone is 80-120°C, the temperature of the second zone is 190-210°C, the temperature of the third zone is 210-230°C, the temperature of the fourth zone is 210-230°C, and the temperature of the fifth zone is 210-230°C. ℃, the temperature in the sixth zone is 210-230 ℃, the temperature in the seventh zone is 210-230 ℃, the temperature in the eighth zone is 210-230 ℃, the temperature in the ninth zone is 210-230 ℃, the speed of the main engine is 250-600 rpm; the length of the twin-screw extruder The diameter ratio is 40:1.

Table 2: Examples and comparative examples polypropylene material components (parts by weight) and test results thereof

Continued Table 2: Components (parts by weight) and test results thereof of embodiment and comparative example polypropylene material

The polypropylene materials in Examples 1-12 have good rigidity and toughness, balanced mechanical properties, and excellent appearance. It is suitable for polypropylene modified materials used in civil engineering, household appliances and vehicles.

The properties of the polypropylene materials in Comparative Examples 1-6 were unbalanced.

Compared with Example 1, in the polypropylene material of Comparative Example 7, the coupling agent in the modified plant fiber used is bis(γ-triethoxysilylpropyl)tetrasulfide, and the prepared polypropylene Although the mechanical properties of the material are balanced, there are many floating fibers in the appearance.

Compared with Example 2, in the polypropylene material of Comparative Example 8, the organic peroxide in the modified plant fiber used was diester peroxydicarbonate, and although the mechanical properties of the prepared polypropylene material were balanced, the appearance was blunt. Fiber is more.

Compared with Example 1, in the polypropylene material of Comparative Example 9, the elastic body of the modified plant fiber used is SEBS. Although the mechanical properties of the prepared polypropylene material are balanced, there are more floating fibers in appearance.

Compared with Example 1, in the polypropylene material of Comparative Example 10, the average fiber length of the plant fiber in the modified plant fiber used is 40-50mm, and although the mechanical properties of the prepared polypropylene material are balanced, the appearance is floating and fibrous. More; in the polypropylene material of comparative example 11, the average length of the plant fiber in the modified plant fiber used is 0.1-0.5mm, although the obtained polypropylene material basically has no floating fiber in appearance, it has poor rigidity and toughness. Well, the mechanical properties are uneven.

Compared with Example 1, among the polypropylene materials of Comparative Example 12 and Comparative Example 13, the melt indices of the polypropylene resins used were respectively 3g/10min and 100g/10min, although the obtained polypropylene materials had good rigidity, but The toughness is poor, and there are many floating fibers in the appearance.

In the polypropylene material of Comparative Example 14, the unmodified jute fiber was used, and the obtained polypropylene material had poor rigidity, poor toughness, and more floating fibers in appearance.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that The technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims

A polypropylene material, characterized in that, in parts by weight, it comprises the following components: 50-90 parts of polypropylene resin, 10-50 parts of modified plant fiber;

Wherein, the modified plant fiber is made of the following raw materials in parts by weight: 50-80 parts of plant fiber, 20-50 parts of POE elastomer, 0.5-2 parts of siloxane coupling agent, 0.1 parts of organic peroxide ~ 1 copy;

The melt index of the polypropylene resin is 5-60g/10min, and the test conditions are: 230°C, 2.16kg;

The average length of the plant fibers is 1-30mm;

The siloxane coupling agent is one or more of amino siloxane coupling agents or epoxy siloxane coupling agents;

The organic peroxide is one or more of alkyl peroxides or acyl peroxides.
The polypropylene material according to claim 1, characterized in that the melt index of the polypropylene resin is 16-50g/10min, and the test conditions are: 230°C, 2.16kg.
The polypropylene material according to claim 1, wherein the plant fiber is at least one of flax fiber, sisal fiber, hemp fiber, jute fiber, kenaf fiber, ramie fiber and bamboo fiber.
The polypropylene material according to claim 1, characterized in that the average length of the plant fibers is 2-10mm.
The polypropylene material according to claim 1, wherein the POE elastomer is at least one of ethylene-octene copolymer and ethylene-butene copolymer.
The polypropylene material according to claim 1, wherein the organic peroxide is benzoyl peroxide, two (tert-butylperoxyisopropyl) benzene, di-tert-butyl peroxide, peroxide At least one of lauryl oxide and dicumyl peroxide.
The polypropylene material according to claim 1, wherein the siloxane coupling agent is γ-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxy At least one of base silane, γ-ureidopropyl triethoxysilane, β-(3,4 epoxycyclohexyl)-ethyl triethoxysilane.
The preparation method of the polypropylene material according to any one of claims 1 to 7, characterized in that it comprises the following steps:

Take polypropylene and modified plant fiber by weight and mix, melt extrude and granulate, and dry to obtain final product;

Wherein, the preparation method of the modified plant fiber is: take the plant fiber, POE elastomer, siloxane coupling agent, and organic peroxide according to the weight parts, and mix to obtain a premix; The premix is granulated, graded, cooled, extruded and granulated, and it is ready.
The application of the polypropylene material according to any one of claims 1 to 7 in polypropylene modified materials for civil construction, household appliances and vehicles.