Aqueous epoxy resins impact-resistant modified core-shell nano emulsion preparation technology
Technical field
The invention belongs to aqueous epoxy resins toughner field, particularly relate to a kind of aqueous epoxy resins impact-resistant modified core-shell nano emulsion preparation technology.
Background technology
Epoxy resin is a kind of three-dimensional netted thermosetting polymer, and be the material that a kind of fragility is very strong, its toughening modifying is the important topic of polymer science and Material Field fundamental research and application and development, is all subject to extensive concern all the time.But simple rubber or elastic body toughening or rigid particles all also exist some shortcomings to epoxy resin roughening.For simple rubber or elastic body toughening polymkeric substance, although impelling strength obtains large increase, usually need the rubber or the elastomerics that add 10wt%-20wt%, this often causes the strength and modulus loss of material too many; And adopt inorganic rigid particle to carry out toughness reinforcing to it, although the strength and modulus of material can not lose, but the toughness increase rate of material is little, and it is not easily dispersed in the polymer, the finely dispersed matrix material of inorganic particulate cannot be obtained, especially to the Inorganic Fillers Filled epoxy-resin systems of nano-scale, because particle has higher surface energy, be easy to occur assemble thus produce defect in the material.
Prior art adopts conventional emulsion polymerization mode to prepare SiO
2/ esters of acrylic acid core-shell particles emulsion, but due to emulsifying process be not suitable for, emulsifier is excessive, the lipophilicity modification degree of silicon-dioxide is low, finally cause that coated with silica rate is low, straight polymer micelle is many, even if there is indivedual core-shell nano, its coating thickness size is also very large and uneven.
Summary of the invention
The object of the invention is: for the deficiencies in the prior art, provide that a kind of clad ratio is high, size uniform, shell thickness are consistent aqueous epoxy resins impact-resistant modified core-shell nano emulsion preparation technology.
In order to achieve the above object, the invention provides a kind of aqueous epoxy resins impact-resistant modified core-shell nano emulsion preparation technology, it comprises the steps:
Steps A, application sol-gel method prepares homodisperse nano silicon, adopts silane coupling agent to carry out surface hydrophobicity modification to it, obtains hydrophobic nature nano silicon;
Step B, adopt pre-emulsification seed emulsion polymerization, the hydrophobic nature nano silicon obtained with steps A is nuclear structure, carries out being polymerized coated, obtain product with methacrylic ester and glycidyl methacrylate monomer.
Beneficial effect of the present invention is as follows: 1. this patent preparation-obtained modified silica particles sphericity is high, size uniform, size distribution are little, without particle adhesion phenomenon; 2. the improved silica rate of weight loss that prepared by this patent is 4.55%, and the percentage of grafting of coupling agent increases substantially; 3. the impact-resistant modified core-shell nano emulsion of the aqueous epoxy resins prepared by the present invention significantly can reduce the loss to matrix modulus as toughner, increases substantially the shock strength of whole toughened system, improves toughness of products.
Accompanying drawing explanation
Fig. 1 is the scanning electron microscope (SEM) photograph of the hydrophobic nature nano-silicon dioxide particle that the embodiment of the present invention one prepares.
Fig. 2 is the transmission electron microscope picture of the hydrophobic nature nano-silicon dioxide particle that the embodiment of the present invention one prepares.
Fig. 3 is the size and distribution test pattern of the hydrophobic nature nano-silicon dioxide particle that the embodiment of the present invention one prepares.
Fig. 4 is the fourier infrared test pattern of the hydrophobic nature nano-silicon dioxide particle that the embodiment of the present invention one prepares.
Fig. 5 is the transmission electron microscope picture of the impact-resistant modified core-shell nano emulsion of aqueous epoxy resins that the embodiment of the present invention one prepares.
Fig. 6 is the size and distribution test pattern of the impact-resistant modified core-shell nano emulsion of aqueous epoxy resins that the embodiment of the present invention one prepares.
Fig. 7 is the scanning electron microscope (SEM) photograph of the silicon dioxide granule that the embodiment of the present invention two prepares.
Fig. 8 is the fourier infrared test pattern of the silicon dioxide granule that the embodiment of the present invention two prepares.
Fig. 9 is the transmission electron microscope picture of the particle emulsion that the embodiment of the present invention two prepares.
Embodiment
The impact-resistant modified core-shell nano emulsion of aqueous epoxy resins prepared by the present invention, the core-shell structure nanometer particle that to comprise with silicon-dioxide be kernel, Surface coating has polymkeric substance, the general molecular formula of described polymkeric substance is:
wherein x=200-300, y=50-100.The diameter of described silicon-dioxide kernel is 290-310nm, and outer cover polymer layer thickness is 30-50nm.
The impact-resistant modified core-shell nano emulsion of described aqueous epoxy resins is as the compare advantage of other toughner of toughner:
1) after this toughner mixes with epoxy resin, the interface rubber content contacted with epoxy molecule segment can be more, inner rubber content less rigidity substances content is more, and such structure toughner significantly can reduce the loss to matrix modulus;
2) this product is in nano-scale, and monodispersity is good, and that can disperse in epoxy resin-base is more even, and after product content reaches threshold value, coordination plasticizing between each toughness reinforcing particle, increases substantially the shock strength of whole toughened system;
3) product polymer shell is designed to methacrylic ester and glycidyl methacrylate monomer carries out copolymerization, enable the hydroxyl of epoxide group with epoxy resin of polymeric shell layer molecule chain end, epoxy group(ing) isoreactivity radical reaction forms covalent linkage, improve the interface interaction between product and matrix, be conducive to the transmission of impact energy, finally can improve toughness.
The invention provides a kind of aqueous epoxy resins impact-resistant modified core-shell nano emulsion preparation technology, it comprises the steps:
Steps A, application sol-gel method prepares homodisperse nano silicon, adopts silane coupling agent to carry out surface hydrophobicity modification to it, obtains hydrophobic nature nano silicon;
Step B, adopt pre-emulsification seed emulsion polymerization, the hydrophobic nature nano silicon obtained with steps A is nuclear structure, carries out being polymerized coated, obtain product with methacrylic ester and glycidyl methacrylate monomer.
Preferably, in described steps A, the add-on of each component is by following volume parts metering:
Its preparation process comprises,
A1, getting segment polarity organic solvent, deionized water and promotor adds in reactor, 6-12min is stirred with 100-400 rev/min of rotating speed, subsequently rotating speed is increased to 800-1500 rev/min, measure simultaneously residue polar organic solvent and tetraethoxy mix, then its mixed solution is dropped in reactor, in question response device mixed solution color by transparent become oyster white after rotating speed is reduced to 100-380 rev/min, keep this tachyphylaxis 2-8h;
A2, continuation is stirred and adjusts the temperature to 40-50 DEG C, then in reactor, adds silane coupling agent, keeps whipping temp reaction 12-30h, and oven dry, washing, again oven dry obtain hydrophobic nature nano silicon.
Preferred further, described steps A 1 Semi-polarity organic solvent and tetraethoxy mixed solution drop rate are 10ml/s-20ml/s.Adopt fast drop and rapid stirring mode, compared to the mode of slow dropping, low rate mixing, preparation-obtained silica dioxide granule sphericity is high, size uniform, size distribution are little, without particle adhesion phenomenon.
Preferred further, described silane coupling agent is γ-methacryloxypropyl trimethoxy silane.
Preferred further, the process of dry in described steps A 2, wash, drying again comprises, dispersion liquid is placed in 40-60 DEG C of air dry oven to dry to pulverulence, then the vacuum drying oven being placed in 60-100 DEG C dries 20-30h, use polar organic solvent centrifuge washing 3-4 time again, finally dry and obtain modified hydrophobic nano silicon.By increasing the step of a step stage drying before centrifuge washing, compared to the mode that then direct centrifuge washing dries, the silane coupling agent percentage of grafting of silica sphere is increased substantially.
By the above preferred implementation of steps A, prepare diameter and be 290-310nm and nano SiO 2 particle of uniform size, and hydrophobic nature modification is carried out to it, make its γ-methacryloxypropyl trimethoxy silane in grafting on the surface.
Preferably, in described step B, the add-on of each component is by following mass fraction metering:
Its preparation process comprises,
B1, adds water, emulsifying agent and assistant for emulsifying agent at reactor, high-speed stirring 15-50min, obtains the aqueous solution of emulsifying agent;
B2, is added to ultrasonic 20-80min in the aqueous solution of the emulsifying agent of step B1 by hydrophobic nature nano silicon, and then stirs 0.5-2h with 100-350 rev/min of rotating speed, obtains hydrophobic nature silicon-dioxide pre-emulsion;
B3, to be added drop-wise to the mixed solution of methacrylate monomer and initiator in the pre-emulsion that B2 step obtains and to stir 0.5-2h, obtaining the monomer droplet of coated silica kernel; Pass into nitrogen 15-35min subsequently, be then heated to 40-90 DEG C, the reaction times is 3-10h, drips glycidyl methacrylate, temperature is brought up to 70-96 DEG C, then continues reaction 0.5-2h, regulates pH value to 6-10, obtains desired product.
Preferred further, described methacrylic ester comprises methyl methacrylate, β-dimethyl-aminoethylmethacrylate, n-BMA or Octyl methacrylate.
Preferred further, described emulsifying agent is sodium lauryl sulphate, Sodium palmityl sulfate, alkylpolyoxyethylene sodium sulfate, Sodium dodecylbenzene sulfonate or sodium laurylsulfonate.
Preferred further, described assistant for emulsifying agent is hexadecanol, n-Hexadecane, palmitic acid, cetylamine, stearyl alcohol or octadecane.
Preferred further, described initiator is hydrogen peroxide, benzoyl peroxide, benzoyl peroxide acetyl or dicumyl peroxide.
By the above preferred implementation of step B, prepare coated thickness 30-50nm and evengranular nuclear shell structure nano silicon-dioxide/polymethacrylate emulsion.The compound emulsifying agent composition of patent of the present invention is different from correlation technique compound emulsifying agent, comprises the assistant for emulsifying agent kind as n-Hexadecane, hexadecanol and so on; The present invention adopts pre-emulsification mode in monomer emulsion process, namely first by hydrophobic nature silicon-dioxide emulsification in emulsifier aqueous solution of modification, and then drip monomer and carry out emulsification, it is silicon-dioxide and monomer emulsifying manner simultaneously that correlation technique generally adopts, compare therewith, pre-emulsification mode can make monomer better be adsorbed on surrounding's formation monomer corona drop layer of silicon-dioxide; Initiator in patent of the present invention adopts oil-soluble initiator, and what correlation technique generally adopted is water soluble starter; Acted synergistically by the overall improvement of these techniques, each drop monomer size of wrapping up silicon-dioxide after making pre-emulsification more evenly, size distribution is less, the core-shell particles shell thickness formed after polymerization meets product requirement more, particle size is also more even, and straight polymer particle and exposed silica dioxide granule ratio significantly reduce.
Below in conjunction with specific embodiment, the invention will be further described, but the present invention is not limited to following examples.
Embodiment 1
A. measure in the reactor that 45 parts of ethanol, 25 parts of deionized waters and 10 parts of ammoniacal liquor adds with magnetic stirring apparatus and stir 10 minutes with 300 revs/min of rotating speeds, subsequently rotating speed is increased to 1000 revs/min, measure 15 parts of ethanol and 4.5 parts of tetraethoxys mix simultaneously, then by its mixed solution fast drop in reactor, in question response device mixed solution color by transparent become oyster white after rotating speed is reduced to 300 revs/min, keep this tachyphylaxis 4h; Continue stir and adjust the temperature to 40-50 DEG C, then in system, 2 parts of silane coupling agents are added, keep whipping temp reaction 24h, after dispersion liquid is placed in 50 DEG C of air dry ovens and dries to pulverulence, then the vacuum drying oven being placed in 80 DEG C dries 24h, use ethanol centrifuge washing 3-4 time again, finally dry and obtain modified hydrophobic nano-silicon dioxide particle.
Product test:
1, Electronic Speculum test, get the nano-silicon dioxide particle of the above-mentioned preparation of 0.02g in 10ml dehydrated alcohol, ultrasonic disperse 30min, then drips on silicon chip, and treat that ethanol volatilizees laggard line scanning electron microscopic observation, test result is shown in Fig. 1; Extremely be with on the copper mesh of carbon film by above-mentioned ultrasonic disperse drop, carry out transmission electron microscope observing after naturally drying, test result is shown in Fig. 2 simultaneously.As shown in Figure 1, prepared silica dioxide granule entirety is all very even, and sphericity is high, without adhesion and agglomeration; As shown in Figure 2, silica particle sizes is 290-310nm, and size uniform.
2, particle diameter test, carry out size and distribution test with Malvern particle diameter tester after getting the dilution of above-mentioned ultrasonic disperse liquid, test result is shown in Fig. 3.As shown in Figure 3, silica dioxide granule is close to monodisperse status.
3, fourier infrared test, dries 10h by the modified manometer silicon dioxide of above-mentioned preparation in 80 DEG C of vacuum drying ovens, and take out and carry out fourier infrared test, analyze the grafting situation of silica sphere coupling agent with this, test result is shown in Fig. 4.As shown in Figure 4, in the improved silica infared spectrum adopting this patent technique to prepare, the carbonyl peak (1720 ~ cm-1) of γ-methacryloxypropyl trimethoxy silane charateristic avsorption band has obvious display, illustrates that grafting density significantly rises; Employing TG test simultaneously (30 ~ 800 DEG C, 10 DEG C/min, N
2protection) also show, adopt the improved silica rate of weight loss prepared of this patent to be 4.55% (additive method prepare product rate of weight loss be 1%), improve 3.5%, illustrate that the percentage of grafting of coupling agent increases substantially.
B. the water of 400 parts is added at reactor, 1 part of sodium lauryl sulphate and 0.08 part of n-Hexadecane, high-speed stirring 30min, modified hydrophobic nano silicon prepared by 3 parts of above-mentioned steps A to be added in the aqueous solution of aforementioned emulsifying agent ultrasonic 1 hour simultaneously, transfer them to subsequently in reactor and stir 1h with 300 revs/min, then 2 parts of butyl methacrylate and 0.04 portion of benzoyl peroxide mixed solution is added dropwise to, nitrogen 30min is passed into after continuing to stir 1h, then start to be heated to 80 DEG C, reaction times is 5h, drip function monomer 0.5 part of glycidyl methacrylate, temperature is brought up to 90 DEG C, continue reaction 1h again, pH value is regulated namely to obtain desired product to 7-8.
Product test:
1, transmissioning electric mirror test, emulsion deionized water prepared by the step B that takes a morsel carries out diluting rear ultrasonic disperse 30min, and then drop on the copper mesh of band carbon film, carry out transmission electron microscope observing after naturally drying, test result is shown in Fig. 5.As shown in Figure 5, whole polymer covering layer is uniformly distributed around silica sphere, is of a size of 30-50nm, and interracial contact is tight.
2, particle diameter test, emulsion deionized water prepared by the step B that takes a morsel carries out diluting rear ultrasonic disperse 30min, and carry out size and distribution test with Malvern particle diameter tester after getting the dilution of above-mentioned ultrasonic disperse liquid, test result is shown in Fig. 6.As shown in Figure 6, core-shell particles dispersity is little, shows that particle size is very even.
Embodiment 2
A. measure in the reactor that 45 parts of ethanol, 25 parts of deionized waters and 10 parts of ammoniacal liquor adds with magnetic stirring apparatus and stir 10 minutes with 300 revs/min of rotating speeds, measure 15 parts of ethanol and 4.5 parts of tetraethoxys mix simultaneously, then its mixed solution dropping funnel is dropped in reactor with 2ml/min speed, dropwise rear reaction 4h; Continue stir and adjust the temperature to 40-50 DEG C, then in system, add 2 parts of silane coupling agents, keep whipping temp reaction 24h, with ethanol centrifuge washing 3-4 time, finally oven dry obtains modified hydrophobic nano-silicon dioxide particle.
Product test:
1, Electronic Speculum test, get the nano-silicon dioxide particle of the above-mentioned preparation of 0.02g in 10ml dehydrated alcohol, ultrasonic disperse 30min, then drips on silicon chip, and treat that ethanol volatilizees laggard line scanning electron microscopic observation, test result is shown in Fig. 7; As shown in Figure 7, particle size is uneven, and adhesion particle is more, reunites serious.
2, fourier infrared test, the modified manometer silicon dioxide of above-mentioned preparation is dried 10h in 80 DEG C of vacuum drying ovens, fourier infrared test is carried out in taking-up, the grafting situation of silica sphere coupling agent is analyzed with this, test result is shown in Fig. 8, as shown in Figure 8, in improved silica infared spectrum, the not display of the charateristic avsorption band carbonyl peak (1720 ~ cm-1) of γ-methacryloxypropyl trimethoxy silane, illustrates that modification is unsuccessful.
B. water and 1 part of sodium lauryl sulphate of 400 parts is added at reactor; high-speed stirring 30min; the nano silicon simultaneously prepared by 3 parts of above-mentioned steps A, 2 portions of butyl methacrylate, 0.08 portion of n-Hexadecane, 0.04 benzoyl peroxide mixed solutions are added drop-wise in the aqueous solution of aforementioned emulsifying agent and stir 1 hour; pass into nitrogen 30min; then start to be heated to 80 DEG C; reaction times is 5h; drip function monomer 0.5 part of glycidyl methacrylate; temperature is brought up to 90 DEG C; continue reaction 1h again, regulate pH value namely to obtain desired product to 7-8.
Product test:
1, transmissioning electric mirror test, emulsion deionized water prepared by the step B that takes a morsel carries out diluting rear ultrasonic disperse 30min, and then drop on the copper mesh of band carbon film, carry out transmission electron microscope observing after naturally drying, test result is shown in Fig. 9.As shown in Figure 9, monomer droplet dispersion is uneven causes the sub-adhesion of core-shell latex particles serious.
Embodiment 3
A. measure in the reactor that 45 parts of ethanol, 30 parts of deionized waters and 10 parts of ammoniacal liquor adds with magnetic stirring apparatus and stir 10 minutes with 300 revs/min of rotating speeds, subsequently rotating speed is increased to 1000 revs/min, measure 15 parts of ethanol and 3 parts of tetraethoxys mix simultaneously, then by its mixed solution fast drop in reactor, in question response device mixed solution color by transparent become oyster white after rotating speed is reduced to 300 revs/min, keep this tachyphylaxis 4h; Continue stir and adjust the temperature to 40-50 DEG C, then in system, 2 parts of silane coupling agents are added, keep whipping temp reaction 24h, after dispersion liquid is placed in 50 DEG C of air dry ovens and dries to pulverulence, then the vacuum drying oven being placed in 80 DEG C dries 24h, use ethanol centrifuge washing 3-4 time again, finally dry and obtain modified hydrophobic nano-silicon dioxide particle;
B. the water of 400 parts is added at reactor, 1 part of sodium lauryl sulphate and 0.08 part of hexadecanol, high-speed stirring 30min, modified hydrophobic nano silicon prepared by 3 parts of above-mentioned steps A to be added in the aqueous solution of aforementioned emulsifying agent ultrasonic 1 hour simultaneously, transfer them to subsequently in reactor and stir 1h with 300 revs/min, then 10 parts of butyl methacrylate and 0.2 portion of benzoyl peroxide mixed solution is added dropwise to, nitrogen 30min is passed into after continuing to stir 1h, then start to be heated to 80 DEG C, reaction times is 5h, drip function monomer 0.5 part of glycidyl methacrylate, temperature is brought up to 90 DEG C, continue reaction 1h again, pH value is regulated namely to obtain desired product to 7-8.
Embodiment 4
A. measure in the reactor that 45 parts of ethanol, 30 parts of deionized waters and 10 parts of ammoniacal liquor adds with magnetic stirring apparatus and stir 10 minutes with 300 revs/min of rotating speeds, subsequently rotating speed is increased to 1000 revs/min, measure 15 parts of ethanol and 3 parts of tetraethoxys mix simultaneously, then by its mixed solution fast drop in reactor, in question response device mixed solution color by transparent become oyster white after rotating speed is reduced to 300 revs/min, keep this tachyphylaxis 4h; Continue stir and adjust the temperature to 40-50 DEG C, then in system, 5 parts of silane coupling agents are added, keep whipping temp reaction 24h, after dispersion liquid is placed in 50 DEG C of air dry ovens and dries to pulverulence, then the vacuum drying oven being placed in 80 DEG C dries 24h, use ethanol centrifuge washing 3-4 time again, finally dry and obtain modified hydrophobic nano-silicon dioxide particle;
B. the water of 400 parts is added at reactor, 5 parts of sodium lauryl sulphate and 0.08 part of n-Hexadecane, high-speed stirring 30min, modified hydrophobic nano silicon prepared by 3 parts of above-mentioned steps A to be added in the aqueous solution of aforementioned emulsifying agent ultrasonic 1 hour simultaneously, transfer them to subsequently in reactor and stir 1h with 300 revs/min, then 8 parts of butyl methacrylate and 0.16 portion of benzoyl peroxide mixed solution is added dropwise to, nitrogen 30min is passed into after continuing to stir 0.2h, then start to be heated to 80 DEG C, reaction times is 5h, drip function monomer 0.5 part of glycidyl methacrylate, temperature is brought up to 90 DEG C, continue reaction 1h again, pH value is regulated namely to obtain desired product to 7-8.
Embodiment 5
A. measure in the reactor that 45 parts of ethanol, 25 parts of deionized waters and 10 parts of ammoniacal liquor adds with magnetic stirring apparatus and stir 10 minutes with 300 revs/min of rotating speeds, subsequently rotating speed is increased to 1000 revs/min, measure 15 parts of ethanol and 4.5 parts of tetraethoxys mix simultaneously, then by its mixed solution fast drop in reactor, in question response device mixed solution color by transparent become oyster white after rotating speed is reduced to 300 revs/min, keep this tachyphylaxis 4h; Continue stir and adjust the temperature to 40-50 DEG C, then in system, 2 parts of silane coupling agents are added, keep whipping temp reaction 24h, after dispersion liquid is placed in 50 DEG C of air dry ovens and dries to pulverulence, then the vacuum drying oven being placed in 80 DEG C dries 24h, use ethanol centrifuge washing 3-4 time again, finally dry and obtain modified hydrophobic nano-silicon dioxide particle;
B. the water of 300 parts is added at reactor, 1 part of sodium lauryl sulphate and 0.08 part of n-Hexadecane, high-speed stirring 30min, modified hydrophobic nano silicon prepared by 3 parts of above-mentioned steps A to be added in the aqueous solution of aforementioned emulsifying agent ultrasonic 1 hour simultaneously, transfer them to subsequently in reactor and stir 1h with 300 revs/min, then the dicumyl peroxide mixed solution of 5 parts of β-dimethyl-aminoethylmethacrylates 0.1 part is added dropwise to, nitrogen 30min is passed into after continuing to stir 1h, then start to be heated to 80 DEG C, reaction times is 5h, drip function monomer 0.5 part of glycidyl methacrylate, temperature is brought up to 90 DEG C, continue reaction 1h again, pH value is regulated namely to obtain desired product to 7-8.