阅读说明：本技术 聚甲基丙烯酸甲酯-三甲基乙烯基苯甲氯化铵-氧化石墨烯复合材料及制备方法 (Polymethyl methacrylate-trimethylvinyl benzylammonium chloride-graphene oxide composite material and preparation method thereof ) 是由 郑俊萍 赵丹 马霖 于 2018-06-21 设计创作，主要内容包括：本发明公开了一种聚甲基丙烯酸甲酯-三甲基乙烯基苯甲氯化铵-氧化石墨烯复合材料,以第二单体三甲基乙烯基苯甲氯化铵对第一单体甲基丙烯酸甲酯聚合物地基体电荷环境进行调控,并且在聚合物基体中引入共轭苯环,两单体通过悬浮聚合方式进行共聚,同时原位添加氧化石墨烯与共聚产物实现复合,将共聚产物提取后热压成型。本发明以甲基丙烯酸甲酯为基材,采用原位悬浮共聚的方法制备纳米复合材料,实现对基体电荷环境的调控,同时在聚合物基体中引入共轭苯环,加入氧化石墨烯填充物进行复合,较纯PMMA树脂,力学性能和热学性能得到大幅度提高,此方法成功地改善了氧化石墨烯在基体中的分散性,解决了PMMA材料在机械性能和热性能方面存在的问题。(The invention discloses a polymethyl methacrylate-trimethylvinyl benzylammonium chloride-graphene oxide composite material, wherein a second monomer, namely trimethylvinyl benzylammonium chloride, is used for regulating and controlling the charge environment of a substrate of a first monomer, namely a methyl methacrylate polymer, a conjugated benzene ring is introduced into the polymer substrate, the two monomers are copolymerized in a suspension polymerization manner, graphene oxide is added in situ to be compounded with a copolymerization product, and the copolymerization product is extracted and then subjected to hot pressing molding. According to the invention, methyl methacrylate is used as a base material, the nanocomposite is prepared by adopting an in-situ suspension copolymerization method, the regulation and control of the charge environment of the base body are realized, meanwhile, a conjugated benzene ring is introduced into a polymer base body, and the graphene oxide filler is added for compounding, so that the mechanical property and the thermal property are greatly improved compared with pure PMMA resin.)

1. The polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is characterized in that the glass transition temperature of the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is 120-125 ℃;

the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is prepared by taking methyl methacrylate as a first monomer and trimethylvinylbenzylammonium chloride as a second monomer through suspension polymerization, wherein the second monomer with positive charges is copolymerized with the first monomer to obtain a positive charge copolymer with a conjugated benzene ring, and the graphene oxide is negatively charged and contains large pi bonds and forms electrostatic attraction and pi-pi interaction with the positive charge copolymer to limit the movement of a polymer molecular chain;

in the suspension polymerization system, the volume ratio of the water phase to the oil phase is (2.5-4.5): the oil phase consists of a first monomer and a second monomer, the dosage of the first monomer is 92-97 wt% of the oil phase, the dosage of the second monomer is 3-8 wt% of the oil phase, the water phase consists of water, graphene oxide, a dispersing agent and a surfactant, the mass of the dispersing agent is 2.5-3 wt% of the oil phase, the mass of the surfactant is 0.1-0.15 wt% of the oil phase, and the mass of the graphene oxide is 0.0-2 wt% of the oil phase;

the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is prepared according to the following steps,

step 1, adding graphene oxide, a dispersing agent and a surfactant into water, and performing ultrasonic dispersion uniformly;

step 2, adding the liquid prepared in the step 1 into a mixed solution of methyl methacrylate and trimethylvinylbenzylammonium chloride, continuously stirring, introducing protective gas to keep the mixed solution in a protective gas atmosphere in the whole reaction process, heating to a temperature higher than the initiation temperature of an initiator, simultaneously adding the initiator to initiate polymerization, and carrying out copolymerization to obtain a methyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide copolymer, wherein the amount of the initiator is 0.8-1.8 wt% of the mass of the oil phase;

and 3, filtering and washing the copolymer prepared in the step 2, and drying to obtain copolymer powder.

2. The polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material according to claim 1, wherein the copolymer powder obtained in the step 3 is hot-pressed and molded by a hot-press molding machine, and the hot-press conditions are as follows: the pressure is 5-10MPa, the temperature is 170-.

3. The polymethylmethacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material according to claim 1, wherein the dispersant is basic magnesium carbonate, calcium hydroxy phosphate, hydroxyethyl cellulose or tricalcium phosphate, and the surfactant is sodium dodecylbenzenesulfonate, sodium dodecyl sulfate or sodium glycocholate.

4. The polymethylmethacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material according to claim 1, wherein the initiator is azobisisobutyronitrile, azobisisoheptonitrile, benzoyl peroxide or bis (2-ethyl) hexyl peroxydicarbonate.

5. The polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material according to claim 1, wherein the protective gas is nitrogen, helium or argon, and the copolymerization temperature in the step 3 is 70-80 ℃ and the copolymerization time is 5-8 hours.

6. The poly (methyl methacrylate) -trimethylvinylbenzylammonium chloride-graphene oxide composite material according to claim 1, wherein the tensile strength of the poly (methyl methacrylate) -trimethylvinylbenzylammonium chloride-graphene oxide composite material is improved by 55-60% and the Young's modulus is improved by 40-45% relative to poly (methyl methacrylate).

7. The poly (methyl methacrylate) -trimethylvinylbenzylammonium chloride-graphene oxide composite material according to claim 1, wherein the temperature T corresponding to 50% weight loss of the poly (methyl methacrylate) -trimethylvinylbenzylammonium chloride-graphene oxide composite material is determined by₅₀380 ℃ plus 385 ℃.

8. The poly (methyl methacrylate) -trimethylvinylbenzylammonium chloride-graphene oxide composite material according to claim 1, wherein the temperature T corresponding to 10% weight loss of the poly (methyl methacrylate) -trimethylvinylbenzylammonium chloride-graphene oxide composite material is determined by₁₀190 ℃ and 195 ℃.

9. The preparation method of the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is characterized by comprising the following steps:

step 1, adding graphene oxide, a dispersing agent and a surfactant into water, and performing ultrasonic dispersion uniformly;

and 2, adding the liquid prepared in the step 1 into an oil phase mixed solution of methyl methacrylate and trimethylvinylbenzylammonium chloride, wherein: the preparation method comprises the following steps of (1) continuously stirring the mixture, wherein the using amount of methyl methacrylate accounts for 92-97 wt% of the mass of an oil phase, the using amount of trimethyl vinyl benzyl ammonium chloride accounts for 3-8 wt% of the mass of the oil phase, the mass of a dispersing agent accounts for 2.5-3 wt% of the mass of the oil phase, the mass of a surfactant accounts for 0.1-0.15 wt% of the mass of the oil phase, the mass of graphene oxide accounts for 0.0l-2 wt% of the mass of the oil phase, introducing protective gas to keep the mixture in a protective gas atmosphere in the whole reaction process, heating the mixture to a temperature higher than the initiation temperature of an initiator, simultaneously adding the initiator to initiate polymerization, and carrying out copolymerization to obtain a methyl methacrylate-trimethyl vinyl benzyl ammonium chloride-graphene oxide copolymer, wherein the using amount of the initiator accounts for 0.8;

and 3, filtering and washing the copolymer prepared in the step 2, and drying to obtain copolymer powder.

10. The application of trimethylvinylbenzylammonium chloride and graphene oxide in synergistically improving the glass transition temperature of a methyl methacrylate-based polymer is characterized in that trimethylvinylbenzylammonium chloride with positive charges and methyl methacrylate are copolymerized to obtain a positive charge copolymer with a conjugated benzene ring, and graphene oxide is negatively charged and contains a large pi bond, forms an electrostatic attraction effect and a pi-pi interaction with the positive charge copolymer, and limits the movement of a polymer molecular chain.

Technical Field

The invention relates to the technical field of composite materials, in particular to a polymethyl methacrylate (PMMA) -trimethylvinyl benzyl ammonium chloride-graphene oxide composite material and a preparation method thereof. PMMA is used as a matrix, the charge environment of the matrix is regulated and controlled, a conjugated benzene ring is introduced, Graphene Oxide (GO) is filled, and the PMMA-based nano composite material is prepared

Background

PMMA, which is an excellent organic synthetic transparent material, replaces ordinary glass due to its excellent light transmission and lightweight characteristics, and is widely used in various lamps, optical glass, commercial advertisement show windows, aircraft side windows, and the like. Besides, PMMA also occupies a place in the fields of medicine, communication, electronic appliances and the like, especially in the field of medical products, PMMA has become a hotspot material in the field due to good biocompatibility, PMMA accounts for about 10 percent of the total dosage of medical polymer materials nowadays, and PMMA used for medical treatment in China is more than 300 tons every year.

As early as 1949, PMMA has been used clinically in the united states for human cranial and articular repair. With the development of the prior art, PMMA is commonly used as a skull repairing material, an artificial bone, an artificial joint, a thoracic cavity filling material, an artificial joint bone cement and the like in medicine, and is more widely applied to false teeth and denture bases. However, PMMA is inherently poor in strength, making it susceptible to fracture and breakage in clinical applications, and a general improvement method is to add nano-fillers such as silica, halloysite, carbon fiber, etc. to enhance the mechanical strength of PMMA-based composites. On the other hand, the heat resistance of PMMA is to be further improved. Due to the characteristic that the nanofiller is easy to agglomerate, the nanofiller can be used after being organically modified, so that the preparation process of the PMMA-based nanocomposite is more complicated and the preparation process is more tedious, and meanwhile, the performance of the PMMA-based nanocomposite can be influenced by the addition of the modifier. These side effects can add to a large extent economic costs for industrial production.

Disclosure of Invention

The invention aims to provide a polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material and a preparation method thereof aiming at the technical defects in the prior art, and the composite material with excellent performance is obtained on the premise of not organically modifying a nano filler. Based on the fact that the surface charge of GO is electronegative, monomers of trimethylvinylbenzylammonium chloride (MBC) and Methyl Methacrylate (MMA) which simultaneously have positive charges and conjugated benzene rings are copolymerized, the regulation and control of the charge environment of a substrate are achieved, the conjugated benzene rings are introduced into the substrate, and then GO nano fillers are added for polymerization.

The technical scheme adopted for realizing the purpose of the invention is as follows:

the glass transition temperature of the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is 120-125 ℃;

the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is prepared by suspension polymerization by taking methyl methacrylate as a first monomer and trimethylvinylbenzylammonium chloride as a second monomer, wherein the second monomer with positive charge is copolymerized with the first monomer to obtain a positive charge copolymer with a conjugated benzene ring, the graphene oxide is negatively charged and contains large pi bonds (the surface of the graphene oxide is composed of carbon six-membered rings, carbon atoms are regularly arranged into a honeycomb structure, each carbon atom is connected with other carbon atoms by sigma bonds, redundant pi electrons and pi electrons of other carbon atoms form delocalized large pi bonds, so that the positive charge copolymer has a strong pi-pi conjugation effect), forming electrostatic attraction and pi-pi interaction with the positive charge copolymer to limit the movement of polymer molecular chains;

in the suspension polymerization system, the volume ratio of the water phase to the oil phase is (2.5-4.5): the oil phase consists of a first monomer and a second monomer, the dosage of the first monomer is 92-97 wt% of the oil phase, the dosage of the second monomer is 3-8 wt% of the oil phase, the water phase consists of water, graphene oxide, a dispersing agent and a surfactant, the mass of the dispersing agent is 2.5-3 wt% of the oil phase, the mass of the surfactant is 0.1-0.15 wt% of the oil phase, and the mass of the graphene oxide is 0.0-2 wt% of the oil phase;

the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is prepared according to the following steps,

step 1, adding graphene oxide, a dispersing agent and a surfactant into water, and performing ultrasonic dispersion uniformly;

step 2, adding the liquid prepared in the step 1 into a mixed solution of methyl methacrylate and trimethylvinylbenzylammonium chloride, continuously stirring, introducing protective gas to keep the mixed solution in a protective gas atmosphere in the whole reaction process, heating to a temperature higher than the initiation temperature of an initiator, simultaneously adding the initiator to initiate polymerization, and carrying out copolymerization to obtain a methyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide copolymer, wherein the amount of the initiator is 0.8-1.8 wt% of the mass of the oil phase;

and 3, filtering and washing the copolymer prepared in the step 2, and drying to obtain copolymer powder.

In the above technical solution, the copolymer powder obtained in step 3 is hot-pressed and molded by a hot-press molding machine, and the hot-press conditions are as follows: the pressure is 5-10MPa, the temperature is 170-200 ℃, and the time is 10-20min, preferably, the pressure is 10MPa, the temperature is 200 ℃, and the time is 15 min.

In the above technical solution, the dispersant is basic magnesium carbonate, calcium hydroxy phosphate (HAP), hydroxyethyl cellulose (HEC) or tricalcium phosphate, preferably hydroxyethyl cellulose (HEC).

In the above technical solution, the volume ratio of the water phase to the oil phase is 4: 1.

in the above technical solution, the surfactant is Sodium Dodecyl Benzene Sulfonate (SDBS), Sodium Dodecyl Sulfate (SDS), or sodium glycocholate, and is preferably Sodium Dodecyl Benzene Sulfonate (SDBS).

In the above technical scheme, the initiator is Azobisisobutyronitrile (AIBN), Azobisisoheptonitrile (ABVN), Benzoyl Peroxide (BPO) or bis (2-Ethyl) Hexyl Peroxydicarbonate (EHP), preferably azobisisobutyronitrile or benzoyl peroxide.

In the above technical solution, the protective gas is nitrogen, helium or argon, preferably nitrogen.

In the technical scheme, the copolymerization temperature in the step 3 is 70-80 ℃, and the copolymerization time is 5-8 hours.

In the technical scheme, the tensile strength of the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material is improved by 55-60% and the Young modulus is improved by 40-45% relative to that of the polymethyl methacrylate.

In the technical scheme, the corresponding temperature T is the weight loss of 50% of the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material₅₀380 ℃ plus 385 ℃.

In the technical scheme, the corresponding temperature T is 10% of weight loss of the polymethyl methacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material₁₀190 ℃ and 195 ℃.

In another aspect of the present invention, a method for preparing a polymethylmethacrylate-trimethylvinylbenzylammonium chloride-graphene oxide composite material includes the following steps:

step 1, adding graphene oxide, a dispersing agent and a surfactant into water, and performing ultrasonic dispersion uniformly;

and 2, adding the liquid prepared in the step 1 into an oil phase mixed solution of methyl methacrylate and trimethylvinylbenzylammonium chloride, wherein: the preparation method comprises the following steps of (1) continuously stirring the mixture, wherein the using amount of methyl methacrylate accounts for 92-97 wt% of the mass of an oil phase, the using amount of trimethyl vinyl benzyl ammonium chloride accounts for 3-8 wt% of the mass of the oil phase, the mass of a dispersing agent accounts for 2.5-3 wt% of the mass of the oil phase, the mass of a surfactant accounts for 0.1-0.15 wt% of the mass of the oil phase, the mass of graphene oxide accounts for 0.0l-2 wt% of the mass of the oil phase, introducing protective gas to keep the mixture in a protective gas atmosphere in the whole reaction process, heating the mixture to a temperature higher than the initiation temperature of an initiator, simultaneously adding the initiator to initiate polymerization, and carrying out copolymerization to obtain a methyl methacrylate-trimethyl vinyl benzyl ammonium chloride-graphene oxide copolymer, wherein the using amount of the initiator accounts for 0.8;

and 3, filtering and washing the copolymer prepared in the step 2, and drying to obtain copolymer powder.

On the other hand, in the application of trimethylvinylbenzylammonium chloride and graphene oxide in synergistically improving the glass transition temperature of a methyl methacrylate-based polymer, trimethylvinylbenzylammonium chloride with positive charges is copolymerized with methyl methacrylate to obtain a positive charge copolymer with a conjugated benzene ring, and graphene oxide is negatively charged and contains large pi bonds, forms electrostatic attraction and pi-pi interaction with the positive charge copolymer, and limits the movement of a polymer molecular chain.

Compared with the prior art, the invention has the beneficial effects that:

among medical composite materials, micro-bead polymer (bead PMMA powder) prepared by suspension polymerization of Methyl Methacrylate (MMA) monomer is the main component of the medical composite material, and has a weight average molecular weight of 60-90 ten thousand, a particle diameter of 30-60 μm, a light transmittance of 90% or more, and a density of about 1.19g/cm³. According to the technical scheme, monomers of trimethyl vinyl benzyl ammonium chloride (MBC) and MMA with positive charges and conjugated benzene rings are copolymerized, so that the regulation and control of a matrix charge environment are realized, the conjugated benzene rings capable of forming pi-pi action with graphene oxide are introduced into a matrix, so that GO is better dispersed in a copolymer matrix, and meanwhile, the interface binding force with the copolymer matrix is enhanced through the interaction of GO and the trimethyl vinyl benzyl ammonium chloride. The micro bead copolymer prepared by suspension polymerization in the technical scheme of the invention meets the basic requirements (such as particle size and weight average molecular weight) of medical composite materials, and after the resin powder is prepared into a standard sample, compared with pure PMMA resin, the mechanical property and the thermal property are greatly improved, and the dispersity of GO in a matrix and the interface bonding force with the matrix are successfully improved.

Drawings

FIG. 1 is a Raman spectrum of the compound extraction residue obtained in example 1 and comparative example 3.

FIG. 2 is a cross-sectional scan of the composite materials obtained in example 1 and comparative example 3.

FIG. 3 is a tensile curve of the composite materials obtained in example 1 and comparative examples 1 to 3.

FIG. 4 is a graph showing the storage modulus curves of the composite materials obtained in example 1 and comparative examples 1 to 3.

FIG. 5 is a graph of the loss factor of the composite material obtained in example 1 and comparative examples 1 to 3.

FIG. 6 is a graph showing the thermogravimetric curves of the composite materials obtained in example 1 and comparative examples 1 to 3.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.