Polyphenylene sulfide-containing composition and method for preparing a thermoplastic composite material

Abstract

The present invention relates to the field of polymer materials, and discloses a polyphenylene sulfide-containing composition and a method for preparing a thermoplastic composite material. The polyphenylene sulfide-containing composition contains polyphenylene sulfide, carbon fiber and a microspherical ionomer having a crosslinked structure, and the ionomer is prepared by the following steps: (1) in an organic solvent, in the presence of a first part of an initiator, maleic anhydride is contacted with a first part of monomer M for reaction, and then a solution containing a crosslinking agent is introduced to continue the reaction, wherein the solution containing the crosslinking agent contains a crosslinking agent, an optional second part of monomer M and an optional second part of an initiator, and monomer M is provided by C4 and / or C5; (2) reacting the product obtained in step (1) with an alkali and a saturated monohydric alcohol. The thermoplastic material prepared from the composition of the present invention can still ensure that the composite material has excellent properties when the amount of carbon fiber used is low.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular, to a composition containing polyphenylene sulfide and a method for preparing a thermoplastic composite material. Background Art

[0002] Polyphenylene sulfide (PPS for short) is a linear crystalline thermoplastic resin with a phenylthio group in the main chain of the molecule. It has excellent heat resistance and a melting point of about 280°C. Polyphenylene sulfide is resistant to high temperature, corrosion, radiation, and wear, and has good dielectric properties, flame retardancy, and mechanical properties. In particular, the heat distortion temperature of the PPS composite material after fiber reinforcement modification can exceed 260°C, and the long-term continuous use temperature is 200 - 240°C. Even in high temperature and high humidity environments, it still has excellent material properties. Due to the large number of benzene rings on the main chain of the PPS molecule, the rigidity of the polymer chain is increased, and the extremely symmetric and regular main chain structure also endows PPS with strong crystallization ability, enabling it to form spherulites even during isothermal crystallization below 200°C. When crystallizing at 160°C, its half-crystallization period is the shortest. Therefore, the forming die temperature of general PPS is required to reach 150°C. Generally, appropriately accelerating the cooling rate can increase the crystallization rate of PPS, but if the cooling rate is too fast, some PPS molecules will not have time to arrange regularly, resulting in a decrease in the crystallinity of PPS, making the material brittle and having poor impact toughness. During the processing and forming process of PPS, factors such as the cooling rate, forming temperature, and heat treatment time will all affect the crystallinity of its resin.

[0003] The crystallization process of thermoplastic polymers directly affects the various properties of polymer materials. When the PPS composite material is formed into a product, its crystallization process directly affects the crystallization morphology and crystallinity of the material. The PPS resin is brittle and has low impact toughness. After being reinforced with carbon fiber, its tensile and bending properties can be significantly improved, but the impact performance is still low. The carbon fiber plays a role of heterogeneous nucleation in the matrix, but due to its content and fiber distribution, it will also affect the movement of molecular chains and inhibit crystallization. Generally, polymers mainly achieve the regulation of the crystallization behavior of polymers by adding nucleating agents or components that promote crystallization nucleation. For example, CN104693802A discloses a high-strength polyphenylene sulfide composite material and its preparation method, using inorganic nano-fillers as nucleating agents to improve the crystallization behavior of the material. In addition, there is also a method of adding copolyether ester as a crystallization promoter for regulation. For example, CN103709750A discloses a carbon fiber-reinforced polyphenylene ether hybrid modified polyphenylene sulfide composite material, which has the advantages of high rigidity, corrosion resistance, and good toughness.

[0004] However, the polyphenylene sulfide composite materials prepared by existing methods still have defects such as poor impact resistance and high brittleness, especially when the amount of carbon fiber used is low. Summary of the Invention

[0005] The object of the present invention is to overcome the problems existing in the prior art, such as poor impact resistance and high brittleness, especially when the amount of carbon fiber used is low. A composition containing polyphenylene sulfide and a method for preparing a thermoplastic composite material are provided.

[0006] The inventors of the present invention have found through research that when the crystallization process of a polymer material (especially polyphenylene sulfide) is regulated by using the microspherical ionomer provided by the present invention, the crystallization temperature can be effectively increased, the crystallization rate can be accelerated, and the impact performance of the material can be improved.

[0007] Therefore, in order to achieve the above object, in the first aspect of the present invention, a composition containing polyphenylene sulfide is provided. The composition contains polyphenylene sulfide, carbon fiber, and a crystallization promoter. Among them, the crystallization promoter is a microspherical ionomer having a cross-linked structure, and the ionomer is prepared by a method including the following steps:

[0008] (1) In an organic solvent, in the presence of a first part of initiator, maleic anhydride and a first part of monomer M are contacted for reaction, and then a solution containing a cross-linking agent is introduced to continue the reaction. Among them, the solution containing the cross-linking agent contains a cross-linking agent, an optional second part of monomer M, and an optional second part of initiator. Monomer M is provided by C4 and / or C5.

[0009] (2) The product obtained in step (1) is mixed with an alkali and a saturated monohydric alcohol for reaction.

[0010] In the second aspect of the present invention, a method for preparing a polyphenylene sulfide thermoplastic composite material is provided. The method includes melt blending the above composition.

[0011] Compared with the prior art, the technical solution provided by the present invention has at least the following advantages:

[0012] 1) By using the ionomer, the composite material prepared from the composition of the present invention has good crystallization properties, and thus has the advantages of high rigidity, corrosion resistance, excellent mechanical properties, good toughness, and high thermal stability.

[0013] 2) When carbon fiber is used as a reinforcing material, the cost of composite processing is relatively high. Therefore, reducing its usage amount is of great significance. In addition, when the amount of carbon fiber used is too much, it will also hinder the movement of molecular chains, resulting in a decrease in crystallinity. However, by using the ionomer of the present invention, the usage amount of carbon fiber can be greatly reduced, and at the same time, the composite material can still have excellent mechanical properties and thermal stability.

[0014] (3) In the composition of the present invention, only a small amount of a crystallization promoter (microspherical ionomer) can better regulate the crystallization behavior of the polymer, and at the same time, it can ensure an appropriate reduction in the amount of carbon fiber used. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. is an infrared spectrum of an ionomer synthesized according to an embodiment of the present invention (Preparation Example 1);

[0016] Figure 2 FIG. is a scanning electron micrograph of an ionomer synthesized according to an embodiment of the present invention (Preparation Example 1);

[0017] Figure 3 FIG. is a scanning electron micrograph of an ionomer synthesized according to an embodiment of the present invention (Preparation Example 1) after being treated with a solvent. DETAILED DESCRIPTION OF THE INVENTION

[0018] The endpoints and any values disclosed herein of a range are not limited to the exact range or value, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0019] The first aspect of the present invention provides a polyphenylene sulfide-containing composition, which composition contains polyphenylene sulfide, carbon fiber, and a crystallization promoter, wherein the crystallization promoter is a microspherical ionomer having a crosslinked structure, and the ionomer is prepared by a method comprising the following steps:

[0020] (1) In an organic solvent, in the presence of a first part of an initiator, maleic anhydride is contacted with a first part of monomer M for reaction, and then a solution containing a crosslinking agent is introduced to continue the reaction, wherein the solution containing the crosslinking agent contains a crosslinking agent, an optional second part of monomer M, and an optional second part of an initiator, and monomer M is provided by C4 and / or C5;

[0021] (2) The product obtained in step (1) is mixed with an alkali and a saturated monohydric alcohol for reaction.

[0022] The dosage ratio of maleic anhydride to monomer M (mixed olefins, C4 and / or C5) can be a conventional selection, but in a preferred embodiment of the present invention, relative to 100 mol of maleic anhydride, the total dosage of the first part of monomer M and the second part of monomer M in terms of terminal olefins is 50 - 150 mol, more preferably 75 - 100 mol.

[0023] In step (1) of the present invention, the monomer M can be fed in one step (i.e., the amount of the second part of the monomer M can be zero), or it can be fed in two parts (i.e., the first part of the monomer M and the second part of the monomer M). According to a more preferred embodiment of the present invention, the molar ratio between the second part of the monomer M and the first part of the monomer M is 0-100:100 (such as 0, 1:100, 5:100, 15:100, 25:100, 30:100, 45:100, 50:100, 60:100, 70:100, 80:100, 90:100, 100:100 or any value between the above values).

[0024] In the present invention, the amount of the organic solvent can be a conventional selection as long as it provides a medium for the reaction in step (1). Preferably, relative to 100 mol of maleic anhydride, the amount of the organic solvent is 50-150 L.

[0025] In step (1) of the present invention, the organic solvent can be a solvent common in various solution polymerization reactions. For example, the organic solvent includes an alkyl ester of an organic acid, that is, it can be an alkyl ester of an organic acid, or a mixture of an alkyl ester of an organic acid and an alkane, or a mixture of an alkyl ester of an organic acid and an aromatic hydrocarbon. Among them, the alkyl ester of the organic acid includes but is not limited to: methyl formate, ethyl formate, propyl formate, butyl formate, isobutyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isoamyl acetate, benzyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, isobutyl butyrate, isoamyl butyrate, isoamyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate, and ethyl phenylacetate. The alkane includes but is not limited to: n-hexane and / or n-heptane. The aromatic hydrocarbon includes but is not limited to: at least one of benzene, toluene, and xylene.

[0026] In the present invention, there is no particular requirement for the amount of the initiator. Preferably, relative to 100 mol of maleic anhydride, the total amount of the first part of the initiator and the second part of the initiator is 0.05-10 mol, and more preferably 1-8 mol.

[0027] In step (1) of the present invention, the initiator can be fed in one step (i.e., the amount of the second part of the initiator can be zero), or can be fed in two parts (i.e., the first part of the initiator and the second part of the initiator). According to a more preferred embodiment of the present invention, the molar ratio between the second part of the initiator and the first part of the initiator is 0-100:100 (such as 0, 1:100, 5:100, 15:100, 25:100, 30:100, 45:100, 50:100, 60:100, 70:100, 80:100, 90:100, 100:100 or any value between the above values).

[0028] In step (1) of the present invention, the initiator can be a reagent commonly used in the art for initiating the polymerization reaction of maleic anhydride and olefins, and can be a thermal decomposition type initiator. Preferably, the initiator is selected from at least one of benzoyl peroxide, diisopropylbenzene peroxide, di-tert-butyl peroxide, lauroyl peroxide, tert-butyl perbenzoate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, azobisisobutyronitrile and azobisisoheptonitrile.

[0029] In the present invention, there is no particular limitation on the amount of the crosslinking agent. Preferably, relative to 100 mol of maleic anhydride, the amount of the crosslinking agent is 1-40 mol, and more preferably 10-20 mol.

[0030] In the present invention, the crosslinking agent can be various common vinyl-containing monomers with two or more functional groups capable of radical polymerization. Preferably, the crosslinking agent is divinylbenzene and / or an acrylate crosslinking agent containing at least two acrylate groups, and the structural formula of the acrylate group is: -O-C(O)-C(R')=CH2, where R' is H or an alkyl group with 1-4 carbon atoms (such as methyl).

[0031] More preferably, the crosslinking agent is selected from at least one of divinylbenzene, propanediol bis(meth)acrylate (such as 1,3-propanediol dimethacrylate, 1,2-propanediol dimethacrylate, 1,3-propanediol diacrylate, 1,2-propanediol diacrylate), ethylene glycol bis(meth)acrylate (ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate), trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, diethylene glycol phthalate diacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and ethoxylated polyfunctional acrylate.

[0032] More preferably, the crosslinking agent is polyethylene glycol diacrylate and / or polyethylene glycol dimethacrylate.

[0033] In step (1), maleic anhydride contacts with monomer M to carry out a reaction first, that is, maleic anhydride and monomer M do not react completely, and only part of them carry out a polymerization reaction in the presence of an initiator. The conditions for the reaction of maleic anhydride with monomer M can be conventional conditions, as long as it is controlled that only part of maleic anhydride and monomer M undergo a polymerization reaction. Preferably, the conditions for the reaction of maleic anhydride with monomer M include: an inert atmosphere, a temperature of 50 - 90 °C (more preferably 60 - 70 °C), a pressure (gauge pressure or relative pressure) of 0.3 - 1 MPa (more preferably 0.4 - 0.5 MPa), and a time of 0.5 - 4 h (more preferably 0.5 - 2 h).

[0034] In step (1), after maleic anhydride contacts with monomer M for a partial reaction, a solution containing a crosslinking agent is introduced to continue the reaction, which is particularly conducive to the formation of a shell crosslinked structure. The conditions for the continued reaction can be conventional conditions, as long as all substrates can participate in the reaction as much as possible. Preferably, the conditions for the continued reaction include: a temperature of 50 - 90 °C, a pressure of 0.3 - 1 MPa, and a time of 2 - 15 h. The temperature and pressure for the continued reaction can be the same as or different from the temperature and pressure for the reaction of maleic anhydride with monomer M described above. According to a more preferred embodiment of the present invention, the way of introducing the solution containing the crosslinking agent to continue the reaction is: at 50 - 90 °C (more preferably 60 - 70 °C), the solution containing the crosslinking agent is added dropwise to the product obtained in step (1) within 1 - 3 h, and then the reaction is continued under insulation for 1 - 4 h.

[0035] In the present invention, there are no special requirements for the type and content of the solvent in the solution containing the crosslinking agent, as long as the solute therein is fully dissolved. Generally, the type of the solvent in the solution containing the crosslinking agent can have the same selection as the organic solvent (that is, including organic acid alkyl esters as described above), and the content of the crosslinking agent in the solution containing the crosslinking agent can be 0.5 - 3 mol / L.

[0036] In step (2) of the present invention, the use of the base makes the percentage of the molar amount of the metal cation in the ionomer accounting for the total molar amount of the structural units provided by maleic anhydride in the ionomer within a certain range, preferably within the above range. The dosage of the base can be a conventional selection. Preferably, relative to 100 mol of maleic anhydride, the dosage of the base is 10 - 100 mol (such as 10 mol, 50 mol, 100 mol or any value between the above values).

[0037] In step (2) of the present invention, the base may be an alkaline substance conventionally used in the art (an alkaline substance capable of providing metal cations (as described above)). Preferably, the base is selected from at least one of metal hydroxides, metal acetates, and metal alkoxides (especially C1-C 10 alkoxides). The metal may be a monovalent metal or a divalent metal, such as a metal of Group IA, Group IIA, and / or Group IIB (especially lithium, sodium, potassium, calcium, barium, zinc, and / or magnesium). More preferably, the base is selected from at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, zinc hydroxide, magnesium hydroxide, lithium acetate, sodium acetate, potassium acetate, calcium acetate, barium acetate, zinc acetate, sodium methoxide, sodium ethoxide, sodium propoxide, sodium isopropoxide, sodium tert-butoxide, sodium tert-pentoxide, sodium isooctoxide, potassium methoxide, lithium methoxide, zinc methoxide, magnesium methoxide, calcium methoxide, potassium ethoxide, barium ethoxide, calcium ethoxide, lithium ethoxide, and potassium tert-butoxide.

[0038] According to the method of the present invention, in step (2), the use of the saturated monohydric alcohol introduces an ester group into the ionomer. There is no particular requirement for the amount of the saturated monohydric alcohol. However, relative to 100 mol of maleic anhydride, the amount of the saturated monohydric alcohol used is preferably 100-20000 mol.

[0039] According to the present invention, the saturated monohydric alcohol can be a conventional choice in the art as long as it can undergo an esterification reaction with the polymer, and can be a straight-chain alkane alcohol, a branched-chain alkane alcohol, or a cycloalkane alcohol. Preferably, the saturated monohydric alcohol is a C1-C 20 (such as C1, C2, C4, C6, C8, C 10 , C 12 , C 15 , C 20 or any value therebetween) saturated monohydric alcohol. More preferably, the saturated monohydric alcohol is selected from at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, 2-methylbutanol, 3-methylbutanol, n-hexanol, cyclohexanol, n-heptanol, n-octanol, n-nonanol, isononanol, n-decanol, 2-propylheptanol, n-dodecanol, n-tetradecanol, n-hexadecanol, and n-octadecanol.

[0040] In step (2) of the present invention, the reaction can be carried out under conventional conditions. For example, the conditions of the reaction include: the temperature is 20-100 °C (preferably 30-100 °C), and the time is 0.5-8 h (preferably 0.5-6 h).

[0041] In the present invention, the product obtained in step (2) can be used to obtain the ionomer through a simple solid-liquid separation step without introducing other reagents (or solvents). The liquid phase obtained through solid-liquid separation can be recycled to step (2). Among them, the method of solid-liquid separation can be solid-liquid separation methods such as filtration and centrifugation. The obtained solid phase can be further dried to obtain the ionomer product.

[0042] The present invention also provides the ionomer prepared by the above method. The ionomer prepared by the present invention has a cross-linked structure and is in the shape of microspheres. The ionomer of the present invention has a dissolution product of ≤ 10% by weight (such as 1% by weight, 2% by weight, 2.5% by weight, 4% by weight, 5.5% by weight, 6.5% by weight, 7.5% by weight, 8.5% by weight, 10% by weight or any value between the above values) in 5 times the weight of acetone at 50 °C for 30 min, and has strong solvent resistance. In the present invention, according to a preferred embodiment, the molar amount of metal cations in the ionomer accounts for 10-100% of the total molar amount of structural unit A provided by maleic anhydride in the ionomer (such as 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 85%, 90%, 95%, 100% or any value between the above values). The cross-linking degree of the ionomer is preferably ≥ 65% (such as 65%, 70%, 75%, 80%, 85%, 90%, 98% or any value between the above values). The average particle size of the ionomer is 150-2000 nm (such as 150 nm, 250 nm, 350 nm, 450 nm, 550 nm, 650 nm, 750 nm, 850 nm, 950 nm, 1050 nm, 1150 nm, 1250 nm, 1350 nm, 1450 nm, 1550 nm, 1650 nm, 1750 nm, 1850 nm, 2000 nm or any value between the above values). The ionomer has a shell cross-linked structure, and thus has better solvent resistance and thermal stability. In the present invention, the metal cation can be various common metal ions, for example, Li + , Na + , K + , Ca 2+ , Mg 2+ , Ba 2+ or Zn 2+ , and its molar content is obtained through X-ray fluorescence spectrometry. The cross-linking degree represents the gel content and is measured by a solvent extraction method. Among them, the test method for the cross-linking degree is: weigh 2-3 grams of the ionomer, record the weight as w1, wrap it with medium-speed qualitative filter paper, put it into a Soxhlet extractor, extract with tetrahydrofuran for 24 hours, dry and weigh the polymer as w2, and calculate the cross-linking degree through w2 / w1. The average particle size is characterized by the number-average particle size and is measured with the aid of a scanning electron microscope.

[0043] In the present invention, the content of the carbon fiber can be a conventional selection. Preferably, relative to 100 parts by weight of polyphenylene sulfide, the content of the carbon fiber is 5 - 70 parts by weight (such as 5, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70 parts by weight or any value between the above values), and preferably 55 - 65 parts by weight.

[0044] In the present invention, the content of the crystallization promoter can be a conventional selection. Preferably, relative to 100 parts by weight of polyphenylene sulfide, the content of the crystallization promoter is 0.1 - 5 parts by weight, and preferably 0.5 - 3 parts by weight.

[0045] In the present invention, the addition of carbon fiber can not only significantly improve the mechanical properties, thermal stability, etc. of the composite material, but also play the role of heterogeneous nucleation and induced crystallization in the composite material; the highly crosslinked microspherical ionomer as a crystallization promoter can effectively improve the crystallization behavior of the polyphenylene sulfide resin to make its crystallization more perfect, so that the composite material has better processing and molding properties.

[0046] According to a preferred embodiment, the composition may further contain a processing aid, and the processing aid may be at least one selected from elastomers, compatibilizers, antioxidants, lubricants, and flow aids.

[0047] More preferably, relative to 100 parts by weight of polyphenylene sulfide, the content of the elastomer is 5 - 20 parts by weight. Any common elastomer in the art can be used in the present invention. Preferably, the elastomer can be selected from at least one of styrene-ethylene-butene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer.

[0048] Relative to 100 parts by weight of polyphenylene sulfide, the content of the compatibilizer is 3 - 15 parts by weight. Any common compatibilizer in the art can be used in the present invention. Preferably, the compatibilizer can be selected from at least one of acrylic compatibilizer, maleic anhydride compatibilizer, and isocyanate compatibilizer.

[0049] In the present invention, the addition of the elastomer and the compatibilizer not only plays the role of toughening but also can synergistically improve the compatibility between the components, so that the tensile and impact properties of the composite material are effectively improved, and a carbon fiber reinforced polyphenylene sulfide composite material with optimized mechanical properties is obtained.

[0050] More preferably, relative to 100 parts by weight of polyphenylene sulfide, the content of the antioxidant is 0.3 - 1 part by weight, preferably 0.3 - 0.5 part by weight. The antioxidant is used to improve the antioxidant performance of the thermoplastic material, and any common antioxidant in the art can be used in the present invention. The antioxidant can be selected from at least one of hindered phenol antioxidants, thioester antioxidants, and amine antioxidants, preferably selected from at least one of antioxidant 1010, antioxidant 1098, antioxidant 1076, antioxidant 2246, antioxidant CA, antioxidant 168, antioxidant 626, and antioxidant 636.

[0051] More preferably, relative to 100 parts by weight of polyphenylene sulfide, the content of the lubricant is 0.1 - 3 parts by weight, preferably 0.3 - 1 part by weight. The lubricant can improve its lubricity while maintaining the performance of the composition, and can be a common lubricant. For example, the lubricant can be selected from at least one of calcium stearate, zinc stearate, oleic acid amide, erucic acid amide, and ethylene bisstearamide.

[0052] More preferably, in order to further improve the fluidity of the resin material, the composition may further contain a flow aid. Among them, relative to 100 parts by weight of polyphenylene sulfide, the content of the flow aid is 0.1 - 1 part by weight, preferably 0.2 - 0.4 part by weight. The flow aid can be a fluoropolymer (for example, purchased from 3M Company, FX5911). The flow aid can improve the flow performance of the polyphenylene sulfide resin.

[0053] In the present invention, in order to endow the composition with more diverse use properties, the composition may further contain other processing aids. Among them, relative to 100 parts by weight of polyphenylene sulfide, the content of the other processing aids is 0.1 - 1 part by weight. The other processing aids can include flame retardants, heat stabilizers, antistatic agents, etc., which can all be conventional selections in the art.

[0054] In the present invention, the resin density of the polyphenylene sulfide can be 0.5 - 2 g / cm 3 , preferably 1 - 1.5 g / cm 3 ; the weight average molecular weight can be 20000 - 60000, preferably 40000 - 60000.

[0055] In the present invention, the single filament diameter of the carbon fiber is 1 - 20 μm, preferably 5 - 7 μm; the tensile strength ≥ 3200 MPa, preferably ≥ 3500 MPa. The carbon fiber can be selected from polyacrylonitrile carbon fiber and / or pitch-based carbon fiber.

[0056] In the second aspect of the present invention, a method for preparing a polyphenylene sulfide thermoplastic composite material is provided, which includes melt blending the above composition.

[0057] In the present invention, the method includes obtaining an ionomer according to the aforementioned method for preparing an ionomer, and then melt-blending polyphenylene sulfide, carbon fiber and the ionomer. The temperature of the melt-blending can be 290 - 330 °C, and the rotation speed can be 200 - 350 rpm.

[0058] In the present invention, the method further includes a process of cooling and extrusion. Among them, the rotation speed of the granulation can be 200 - 500 rpm.

[0059] The method is generally implemented in a twin-screw extruder. Preferably, after metering polyphenylene sulfide, an ionomer and optional partial processing aids (compatibilizer, antioxidant, flow aid, etc.) according to the formula, they are uniformly stirred at a high speed and put into the main feeder of the twin-screw extruder. The carbon fiber is traction-added from the fiber feeding port of the screw, and the optional partial processing aid (flow aid) is added laterally. After melt plasticization and extrusion, it is cooled and granulated to prepare a composite material containing polyphenylene sulfide.

[0060] In order to obtain a thermoplastic composite material, the method may further include drying and molding the product after cooling and granulation, preferably by injection molding in an injection molding machine. The specific methods of drying and molding are well-known to those skilled in the art and will not be elaborated here.

[0061] The present invention will be described in detail below through examples.

[0062] In the following examples, polyphenylene sulfide (NHU-PPS 1190C) was purchased from Zhejiang NHU Co., Ltd.; the carbon fiber was purchased from Shanghai Petrochemical Co., Ltd. The carbon fiber had an epoxy sizing agent, a 12k small tow, and a single filament diameter of 5 - 7 μm; the compatibilizer (CMG5805) was purchased from Jiangsu Jiayirong Compatibilizer Co., Ltd.; the lubricant (oleic acid amide (CrodamidaVRX)) was purchased from Croda International Plc; the antioxidant (antioxidant 1010 and antioxidant 168, with a compounding weight ratio of 1:1) was purchased from BASF SE.

[0063] The present invention will be described in detail below through examples. In the following examples and comparative examples, the conditions for vacuum drying were: 100 °C, a vacuum degree of -0.095 MPa, and a time of 8 h.

[0064] Preparation Example 1

[0065] This preparation example is used to illustrate the microspherical ionomer (or ionomer microspheres) having a cross-linked structure used in the present invention and its preparation method.

[0066] (1) The composition of the mixed butene gas is as follows: trans-2-butene, 40.83 wt%; cis-2-butene, 18.18 wt%; n-butane, 24.29 wt%; 1-butene, 9.52 wt%; isobutene, 2.78 wt%; others, 4.4 wt%. 100 g of maleic anhydride and 6 g of azobisisobutyronitrile were dissolved in 800 mL of isoamyl acetate to form Solution 1. The measured mixed butene was introduced (the molar ratio of maleic anhydride to the active component (terminal olefin) in the mixed olefins was 1:1). Under a nitrogen atmosphere, the reaction was carried out at 70 °C and 0.5 MPa for 1 hour;

[0067] (2) 25 g of divinylbenzene was dissolved in 200 mL of isoamyl acetate to form Solution 2. Solution 2 was added to the reaction system by a piston pump and added dropwise for 2 hours. After the addition was completed, the reaction system continued to be kept warm and reacted for 3 hours. The reaction system was centrifuged at 5000 rad / min for 30 minutes to obtain crosslinked shell butene / maleic anhydride polymer microspheres, which were washed and purified with n-hexane and dried under vacuum.

[0068] (3) 50 g of crosslinked shell butene / maleic anhydride polymer microspheres and 10.8 g of sodium hydroxide (the amount of base used was 1 mol relative to each mole of maleic anhydride) were added to 200 mL of methanol, and the reaction was carried out at 64.7 °C for 5 hours. The reaction system was centrifuged at 5000 rad / min for 20 minutes. The solid was stirred and washed with 300 mL of methanol, centrifuged at 5000 rad / min for 20 minutes, the solid was stirred and washed with 300 mL of methanol, centrifuged at 5000 rad / min for 20 minutes, and the solid was dried under vacuum to obtain crosslinked shell butene / methyl maleate sodium ionomer microspheres (denoted as C1). Figure 2 Figure shows the scanning electron micrograph of the ionomer microspheres. It can be seen that C1 is a dispersed microsphere.

[0069] (4) 10.00 g of C1 was weighed and added to 50 g of acetone, and stirred at 50 °C for 30 min. The system was centrifuged at 5000 rad / min for 30 minutes, dried under vacuum and weighed. The polymer was 9.29 g and the eluate was 0.71 g. Figure 3 Figure shows the scanning electron micrograph of the ionomer microspheres after solvent treatment. Comparing Figure 2 and Figure 3 it can be seen that the morphology of the ionomer microspheres changed less after being treated with the solvent.

[0070] Preparation Example 2

[0071] This preparation example is used to illustrate the ionomer microspheres used in the present invention and their preparation method.

[0072] (1) Dissolve 100 g of maleic anhydride and 5 g of azobisisobutyronitrile in 800 mL of isopentyl acetate to form Solution 1. Introduce the metered mixed butene (with the same composition as in Example 1, and the molar ratio of maleic anhydride to the effective component (terminal olefin) in the mixed olefins is 1:1). Under a nitrogen atmosphere, react at 70 °C and 0.4 MPa for 2 hours;

[0073] (2) Dissolve 15 g of divinylbenzene in 200 mL of isopentyl acetate to form Solution 2. Add Solution 2 to the reaction system using a piston pump, and add dropwise for 2 hours. After the addition is completed, keep the reaction system at the same temperature for reaction for 3 hours. The reaction system is centrifuged at 5000 rad / min for 30 minutes to obtain crosslinked shell butene / maleic anhydride polymer microspheres, which are washed and purified with methanol and then dried in vacuum.

[0074] (3) Add 50 g of crosslinked shell butene / maleic anhydride polymer microspheres and 15.4 g of sodium ethoxide (the amount of base used is 0.88 mol per mole of maleic anhydride) to 300 mL of ethanol, and react at 78 °C for 5 hours. The reaction system is centrifuged at 5000 rad / min for 20 minutes. The solid is stirred and washed with 300 mL of ethanol, centrifuged at 5000 rad / min for 20 minutes, the solid is stirred and washed with 300 mL of ethanol, centrifuged at 5000 rad / min for 20 minutes, and the solid is dried in vacuum to obtain crosslinked shell butene / sodium maleate ionomer microspheres (denoted as C2).

[0075] (4) Weigh 10.00 g of C2 and add it to 50 g of acetone, and stir at 50 °C for 30 min. The system is centrifuged at 5000 rad / min for 30 minutes, dried in vacuum and then weighed. The polymer is 9.4 g and the extract is 0.6 g. Similar to C1, the morphology change of the microspheres before and after solvent treatment is small.

[0076] Preparation Example 3

[0077] This preparation example is used to illustrate the ionomer microspheres used in the present invention and their preparation method.

[0078] (1) Dissolve 100 g of maleic anhydride and 2.5 g of azobisisobutyronitrile in 800 mL of isopentyl acetate to form Solution 1. Introduce the metered mixed butene (with the same composition as in Example 1, and the molar ratio of maleic anhydride to the effective component (terminal olefin) in the mixed olefins is 1:0.75). Under a nitrogen atmosphere, react at 70 °C and 0.5 MPa for 1 hour;

[0079] (2) 0.5 g of azobisisobutyronitrile and 18 g of divinylbenzene were dissolved in 200 mL of isopentyl acetate to form Solution 2. Solution 2 was added to the reaction system by a plunger pump and dropped for 2 hours. After the dropping was completed, the reaction system was kept warm and reacted for another 3 hours. Crosslinked shell butene / maleic anhydride polymer microspheres were obtained, washed and purified with methanol, and dried in vacuum.

[0080] (3) 50 g of crosslinked shell butene maleic anhydride polymer microspheres and 10.1 g of sodium hydroxide (the amount of base used was 0.9 mol per mole of maleic anhydride) were added to 300 mL of methanol and reacted at 50 °C for 5 hours. The reaction system was centrifuged at 5000 rad / min for 20 minutes. The solid was stirred and washed with 300 mL of methanol, centrifuged at 5000 rad / min for 20 minutes, the solid was stirred and washed with 300 mL of methanol, centrifuged at 5000 rad / min for 20 minutes, and the solid was dried in vacuum to obtain crosslinked shell butene / methyl maleate sodium ionomer microspheres (denoted as C3).

[0081] (4) Weighed 10.00 g of C3 and added it to 50 g of acetone, and stirred at 50 °C for 30 min. The system was centrifuged at 5000 rad / min for 30 minutes, dried in vacuum and weighed. The polymer was 9.42 g and the eluate was 0.58 g. Similar to C1, the morphology of the microspheres changed little before and after solvent treatment.

[0082] Preparation Example 4

[0083] This preparation example is used to illustrate the ionomer microspheres used in the present invention and their preparation method.

[0084] (1) The composition of the mixed C5 gas was as follows: diolefins (isoprene, cyclopentadiene, 1,4-pentadiene, piperylene), 47.83 wt%; monoolefins (1-pentene, 2-pentene, cyclopentene, 2-methyl-1-butene, 2-methyl-2-butene), 13.18 wt%; alkanes (n-pentane, isopentane, cyclopentane, 2-methylbutane), 21.29 wt%; alkynes (2-butyne, 3-penten-1-yne), 0.92 wt%; others, 16.78 wt%. 100 g of maleic anhydride and 2 g of azobisisobutyronitrile were dissolved in 800 mL of isopentyl acetate to form Solution 1, and the measured mixed C5 was introduced (the molar ratio of maleic anhydride to the effective component (terminal olefin) in the mixed olefins was 1:0.5). Under a nitrogen atmosphere, the reaction was carried out at 70 °C and 0.5 MPa for 1 hour;

[0085] (2) The metered mixed C5 (the molar ratio of maleic anhydride to the active component (terminal olefin) in this part of the mixed olefins is 1:0.5) and 15 g of divinylbenzene are dissolved in 200 mL of isopentyl acetate to form Solution 2. Solution 2 is added to the reaction system by a plunger pump and dropped for 2 hours. After the dropping is completed, the reaction system continues to be kept warm and react for 3 hours. Crosslinked pentene / maleic anhydride polymer microspheres are obtained, washed and purified with methanol, and dried under vacuum.

[0086] (3) 50 g of the crosslinked pentene maleic anhydride polymer microspheres and 10.7 g of sodium hydroxide (the amount of alkali used is 0.9 mol relative to each mole of maleic anhydride) are added to 300 mL of methanol and reacted at 50 °C for 5 hours. The reaction system after reaction is centrifuged at 5000 rad / min for 20 minutes. The solid is stirred and washed with 300 mL of methanol, centrifuged at 5000 rad / min for 20 minutes, the solid is stirred and washed with 300 mL of methanol, centrifuged at 5000 rad / min for 20 minutes, and the solid is dried under vacuum to obtain crosslinked pentene / methyl maleate sodium ionomer microspheres (denoted as C4).

[0087] (4) Weigh 10.00 g of C4 and add it to 50 g of acetone, and stir at 50 °C for 30 min. The system is centrifuged at 5000 rad / min for 30 minutes, dried under vacuum and weighed. The polymer is 9.37 g and the eluate is 0.63 g. Similar to C1, the morphology of the microspheres changes little before and after solvent treatment.

[0088] Test Example 1

[0089] (1) Infrared spectrum analysis is carried out on the ionomer microspheres obtained in Preparation Example 1, and the results are respectively as Figure 1 shown. It can be seen from the infrared spectrum analysis results that the ionomer is successfully synthesized. The infrared spectrum analysis results of Preparation Examples 2-4 are similar to those of Preparation Example 1, and crosslinked ionomers are successfully obtained.

[0090] (2) The ionomer microspheres prepared in the above Preparation Examples are subjected to X-ray fluorescence spectrum analysis to determine the content of metal cations in the ionomer.

[0091] (3) The average particle size and crosslinking degree of the polymers prepared in the above Preparation Examples are measured (particle size test method: select 500 microspheres in the electron microscope photo, measure their diameters, and calculate the average particle size of the microspheres by the mathematical average method; crosslinking degree determination method: weigh 2-3 g of polymer microspheres (w1), wrap them with medium-speed qualitative filter paper, put them into a Soxhlet extractor, extract with tetrahydrofuran for 24 hours, dry and weigh the polymer w2, and calculate the crosslinking degree through w2 / w1). The results are shown in Table 1 below.

[0092] Table 1

[0093]

[0094] (4) The ionomer microspheres prepared in the above preparation examples were respectively mixed uniformly with PPS. The addition amount of the ionomer microspheres was 1% of the weight of PPS. Then, they were melt-blended at 300 °C for 8 minutes and extruded and pelletized to obtain modified polyphenylene sulfide. The modified PPS was subjected to differential scanning calorimetry (DSC) testing, and the unmodified PPS was used as a control.

[0095] Table 2

[0096]

[0097]

[0098] It can be seen from the data in Table 2 that the ionomers prepared by this method can significantly increase the crystallization temperature of PPS and accelerate the crystallization rate.

[0099] Examples 1 - 4

[0100] Weigh 100 parts by weight of PPS, ionomers (C1 to C4), processing aids (elastomer, compatibilizer, antioxidants (1010 and antioxidant 168, compounding ratio 1:1), lubricant, etc.) according to the formula in Table 3 (all in parts by weight), put them into a high-speed mixer and mix evenly, then add them into a twin-screw extruder; the carbon fiber tow (carbon fiber, CF) is drawn in through the fiber inlet of the extruder screw. Each material is melt-blended in the twin-screw extruder, and the processing temperatures of each section of the screw are 325 °C, 330 °C, 335 °C, 335 °C, 335 °C, 330 °C, and pelletized by extrusion at a speed of 300 rpm.

[0101] Example 5

[0102] It was carried out in the same manner as in Example 1, except that the amounts of the ionomer and carbon fiber were changed. The specific formula is shown in Table 3.

[0103] Table 3

[0104]

[0105]

[0106] Comparative Examples 1 - 4

[0107] The experiments were respectively carried out in the same method as in Examples 1 - 4, except that the ionomer microspheres were not used and the amounts of some processing aids were changed. The specific formula is shown in Table 3, and the performance test results are shown in Table 4.

[0108] Test Example 2

[0109] The pellets obtained from the above examples and comparative examples were dried in a forced-air oven at 140 °C for about 5 hours, then added to an injection molding machine for injection molding to obtain standard specimens. The temperatures of each section of the injection molding machine were 310 °C, 320 °C, 320 °C, 325 °C, 325 °C, the mold temperature was 140 °C, the holding pressure was 60 MPa, the holding time was 90 s, and the cooling time was 10 s. Injection-molded samples were prepared and their properties were tested. The test results are shown in Table 4.

[0110] The tensile strength and elongation at break were determined in accordance with ISO527-2;

[0111] The flexural strength and flexural modulus were tested in accordance with GB / T9341;

[0112] The notched Izod impact strength of the simply supported beam was determined in accordance with GB / T 1043-1993;

[0113] The heat distortion temperature was determined in accordance with GB / T1634.

[0114] Table 4

[0115]

[0116] As can be seen from the above results, for the above examples and comparative examples, using highly crosslinked ionomer microspheres as a crystallization promoter can promote high-temperature crystallization, increase the crystallization rate, optimize the crystallization behavior, enable carbon fibers to effectively play the role of a reinforcing body, cooperate with other components (such as carbon fibers, processing aids, etc.), and optimize the mechanical properties of the composite material. For example, the tensile and impact properties of the composite material can be further improved, or the content of each component can be controlled within the preferred range, which can further improve the properties of the thermoplastic composite material.

[0117] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of technical features. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A polyphenylene sulfide-containing composition, characterized in that, The composition contains polyphenylene sulfide, carbon fiber and a crystallization promoter. Among them, the crystallization promoter is a microspherical ionomer with a crosslinked structure, and the ionomer is prepared by a method including the following steps: (1) In an organic solvent, in the presence of a first part of initiator, maleic anhydride and a first part of monomer M are contacted and reacted, and then a solution containing a crosslinking agent is introduced to continue the reaction. Among them, the solution containing the crosslinking agent contains a crosslinking agent, an optional second part of monomer M and an optional second part of initiator, and monomer M is provided by C4 and / or C5; (2) The product obtained in step (1) is mixed with an alkali and a saturated monohydric alcohol for reaction; Among them, relative to 100 parts by weight of polyphenylene sulfide, the content of the carbon fiber is 5-70 parts by weight, and the content of the crystallization promoter is 0.1-5 parts by weight; Relative to 100 mol of maleic anhydride, the total amount of the first part of monomer M and the second part of monomer M in terms of terminal olefins is 50-150 mol; the amount of the organic solvent is 50-150 L; the total amount of the first part of initiator and the second part of initiator is 0.05-10 mol; the amount of the crosslinking agent is 1-40 mol; the amount of the alkali is 10-100 mol; the amount of the saturated monohydric alcohol is 100-20000 mol; The crosslinking agent is divinylbenzene; The eluate of the ionomer in 5 times the weight of acetone at 50 °C for 30 min ≤ 10% by weight; the molar amount of metal cations in the ionomer accounts for 10-100% of the total molar amount of structural unit A provided by maleic anhydride in the ionomer; the crosslinking degree of the ionomer ≥ 60%, it is microspherical and the average particle size is 150-2000 nm; Among them, the test method for the crosslinking degree is: Weigh 2-3 grams of the ionomer, record the weight as w1, wrap it with medium-speed qualitative filter paper, put it into a Soxhlet extractor, extract with tetrahydrofuran for 24 hours, dry the polymer and weigh w2, and calculate the crosslinking degree through w2 / w1.

2. The composition according to claim 1, wherein, Relative to 100 mol of maleic anhydride, the total amount of the first part of monomer M and the second part of monomer M in terms of terminal olefins is 75-100 mol; the total amount of the first part of initiator and the second part of initiator is 1-8 mol; the amount of the crosslinking agent is 10-20 mol.

3. The composition according to claim 1, wherein, The molar ratio between the second part of monomer M and the first part of monomer M is 0-100:100; and / or, the molar ratio between the second part of initiator and the first part of initiator is 0-100:100; and / or, the organic solvent includes alkyl organic acid esters; and / or, the initiator is selected from at least one of benzoyl peroxide, diisopropylbenzene peroxide, di-tert-butyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, azobisisobutyronitrile and azobisisoheptonitrile; and / or, the alkali is selected from at least one of metal hydroxides, metal acetates and metal alkoxides; and / or, the saturated monohydric alcohol is selected from C1-C20 saturated monohydric alcohols.

4. The composition according to claim 3, wherein The base is selected from at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, zinc hydroxide, magnesium hydroxide, lithium acetate, sodium acetate, potassium acetate, calcium acetate, barium acetate, zinc acetate, sodium methoxide, sodium ethoxide, sodium n-propoxide, sodium isopropoxide, sodium tert-butoxide, sodium tert-pentoxide, sodium isooctoxide, potassium methoxide, lithium methoxide, zinc methoxide, magnesium methoxide, calcium methoxide, potassium ethoxide, barium ethoxide, calcium ethoxide, lithium ethoxide and potassium tert-butoxide; and / or, the saturated monohydric alcohol is selected from at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, 2-methylbutanol, 3-methylbutanol, n-hexanol, cyclohexanol, n-heptanol, n-octanol, n-nonanol, isononanol, n-decanol, 2-propylheptanol, n-dodecanol, n-tetradecanol, n-hexadecanol and n-octadecanol.

5. The composition according to claim 1, wherein In step (1), the conditions for the reaction of maleic anhydride with monomer M include: an inert atmosphere, a temperature of 50 - 90 °C, a pressure of 0.3 - 1 MPa, and a time of 0.5 - 4 h.

6. The composition according to claim 1, wherein, In step (1), the conditions for introducing the solution containing the crosslinking agent and continuing the reaction include: a temperature of 50 - 90 °C, a pressure of 0.3 - 1 MPa, and a time of 2 - 15 h; and / or, the manner of introducing the solution containing the crosslinking agent and continuing the reaction is: at 50 - 90 °C, the solution containing the crosslinking agent is added dropwise to the reaction system within 1 - 3 h, and then the reaction is continued under heat preservation for 1 - 4 h.

7. The composition according to claim 1, wherein In step (2), the conditions for the reaction include: a temperature of 20 - 100 °C and a time of 0.5 - 8 h.

8. The composition according to claim 1, wherein The composition further contains at least one of an elastomer, a compatibilizer, an antioxidant, a lubricant and a flow aid.

9. The composition according to claim 8, wherein, Relative to 100 parts by weight of polyphenylene sulfide, the content of the elastomer is 5 - 20 parts by weight; and / or, relative to 100 parts by weight of polyphenylene sulfide, the content of the compatibilizer is 3 - 15 parts by weight; and / or, relative to 100 parts by weight of polyphenylene sulfide, the content of the antioxidant is 0.3 - 1 part by weight; and / or, relative to 100 parts by weight of polyphenylene sulfide, the content of the lubricant is 0.1 - 3 parts; and / or, relative to 100 parts by weight of polyphenylene sulfide, the content of the flow aid is 0.1 - 1 part by weight.

10. The composition according to claim 1, wherein, The resin density of the polyphenylene sulfide is 0.5 - 2 g / cm 3 ; the weight-average molecular weight is 20,000 - 60,000; and / or, the carbon fiber is a polyacrylonitrile carbon fiber, the monofilament diameter of the carbon fiber is 1 - 20 μm; the tensile strength ≥ 3500 MPa.

11. The composition according to claim 10, wherein, The resin density of the polyphenylene sulfide is 1-1.5 g / cm 3 ; the weight-average molecular weight is 40,000-60,000; and / or, the monofilament diameter of the carbon fiber is 5 - 7 μm.

12. A method for preparing a polyphenylene sulfide thermoplastic composite, characterized in that, The method includes melt blending the composition according to any one of claims 1 - 11.

13. Use of the composition according to any one of claims 1 - 11 in enhancing the rigidity, corrosion resistance, mechanical properties, toughness and thermal stability of polyphenylene sulfide thermoplastic composites.

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