阅读说明：本技术 超分子自组装增韧改性三聚氰胺树脂的制备方法和应用 (The preparation method and application of Supramolecular self assembly toughening modifying melamine resin ) 是由 吴志刚 雷洪 张本刚 余丽萍 李利芬 杜官本 于 2019-08-29 设计创作，主要内容包括：本发明公开了超分子自组装增韧改性三聚氰胺树脂的制备方法,包括表面改性高岭石制备和增韧改性三聚氰胺树脂制备,表面改高岭石制备：超声分散将高岭石分散在去离子水中,加入表面改性剂拌匀,经恒温、离心、洗涤、干燥获得；增韧改性三聚氰胺树脂制备：超声分散将表面改性高岭石和多聚甲醛分散在有机溶剂中,调pH后加三聚氰胺,保温、冷却、调pH制得。本申请利用表面改性高岭石与三聚氰胺分子形成超分子堆积体系,通过三嗪环π-π超分子堆积在三聚氰胺树脂中的构筑,使三聚氰胺树脂在形成时为层状超分子堆积结构,从而实现对三聚氰胺树脂的增韧,韧性增幅250～400％,且三聚氰胺树脂游离甲醛含量较低,力学性能和耐热性能较高。(The invention discloses the preparation methods of Supramolecular self assembly toughening modifying melamine resin, including the preparation of surface modified kaolinite and the preparation of toughening modifying melamine resin, surface changes kaolinite preparation: ultrasonic disperse disperses kaolinite in deionized water, surface modifier is added to mix thoroughly, through constant temperature, centrifugation, washing, dry acquisition；The preparation of toughening modifying melamine resin: ultrasonic disperse disperses surface modified kaolinite and paraformaldehyde in organic solvent, to add melamine after adjusting pH, heat preservation, cooling, tune pH are made.The application forms supermolecule using surface modified kaolinite and melamine molecule and accumulates system, constructing in melamine resin is deposited in by triazine ring π-π supermolecule, make melamine resin stratiform supermolecule packed structures when being formed, to realize the toughening to melamine resin, toughness amplification 250~400%, and melamine resin free formaldehyde content is lower, mechanical property and heat resistance are higher.)

1. a kind of preparation method of Supramolecular self assembly toughening modifying melamine resin, it is characterised in that: the preparation method The preparation of preparation and toughening modifying melamine resin including surface modified kaolinite, the surface changes kaolinic preparation It is: it is using ultrasonic disperse that kaolinite is evenly dispersed in deionized water, surface modifier is then added and stirs evenly, then through perseverance Temperature processing, centrifugation, washing, drying, obtain surface modified kaolinite；The preparation of toughening modifying melamine resin is: using super Sound dispersion is evenly dispersed in organic solvent by surface modified kaolinite and paraformaldehyde, and melamine is added after adjusting pH value, Isothermal holding after mixing evenly, then through cooling, adjusting pH value, the Supramolecular self assembly toughening modifying melamine tree is made Rouge.

2. the preparation method of Supramolecular self assembly toughening modifying melamine resin according to claim 1, feature exist In, comprising the following steps:

(1) preparation of surface modified kaolinite

Kaolinite and surface modifier are weighed according to parts by weight, and kaolinite is placed in deionized water, it is equal by ultrasonic disperse It is even, surface modifier is then added, after mixing evenly, water bath with thermostatic control is heated and stirred, and centrifugation is washed with deionized 2~3 It is dry to constant weight after secondary, obtain surface modified kaolinite；

(2) preparation of toughening modifying melamine resin

The surface modified kaolinite and paraformaldehyde that step (1) is obtained are added in organic solvent, then ultrasonic disperse processing is used NaOH solution adjusts pH value to 8.5~9.0, adds melamine, stirs evenly, white when occurring after heating and isothermal holding When color flocculent deposit, stop reaction and material is cooled to 40 DEG C, adjusts pH value to 9.0, obtain the Supramolecular self assembly and increase Tough modified cyanurotriamide resin.

3. the preparation method of Supramolecular self assembly toughening modifying melamine resin according to claim 2, feature exist In: in step (1), the temperature of the water bath with thermostatic control is 85~90 DEG C, and the time being stirred to react is 7.5~9h；The drying Temperature is 105~130 DEG C；The revolving speed of the centrifugation is 3500~4500r/min.

4. the preparation method of Supramolecular self assembly toughening modifying melamine resin according to claim 2, feature exist In: in step (2), the mass concentration of the NaOH solution is 30%；The temperature of the isothermal holding is 85~90 DEG C, and the time is 12~18h, pH value control is 8.5~9.0 when insulation reaction.

5. the preparation method of Supramolecular self assembly toughening modifying melamine resin according to claim 2, feature exist In: in step (1) and step (2), the frequency of the ultrasonic disperse is 25~35KHz, and the time is 20~30min.

6. the preparation method of Supramolecular self assembly toughening modifying melamine resin according to claim 1 or 2, feature Be: the kaolinite, organic solvent, surface modifier, paraformaldehyde and melamine are matched according to following parts by weight: 5~15 parts of kaolinite, 135~165 parts of organic solvent, 2~6 parts of surface modifier, 100~150 parts of paraformaldehyde, melamine 40~80 parts.

7. the preparation method of Supramolecular self assembly toughening modifying melamine resin according to claim 1 or 2, feature Be: the organic solvent is one of benzene, toluene, acetone, chloroform, dimethyl sulfoxide, triethanolamine, styrene or one kind More than.

8. the preparation method of Supramolecular self assembly toughening modifying melamine resin according to claim 1 or 2, feature Be: the surface modifier is neopelex, lauryl sodium sulfate, dodecyl trimethyl ammonium bromide, ten Six alkyl trimethyl ammonium bromides, trimethylolpropane, Silane coupling agent KH550, two or more in acidic ionic liquid.

9. Supramolecular self assembly toughening modifying melamine resin made from a kind of preparation method as described in claim 1~8, It is characterized by: the performance indicator of the Supramolecular self assembly toughening modifying melamine resin are as follows: free formaldehyde content is lower, Mechanical property and heat resistance are higher, and toughness is remarkably improved, and toughness amplification is 250~400%.

10. the application of Supramolecular self assembly toughening modifying melamine resin according to claim 9, it is characterised in that: Applied in leather industry, optical material, foamed material, moulding compound, paper industry, timber industry and other industrial productions, have Have the characteristics that free formaldehyde content is low, toughness is strong.

Technical field

The invention belongs to technical field of polymer materials more particularly to a kind of Supramolecular self assembly toughening modifying melamines The preparation method and application of resin.

Background technique

Melamine resin is the abbreviation of melamine resin, it be by melamine and formaldehyde underwent hydroxymethylation again The high-molecular compound connected by methylene or ehter bond formed after polycondensation reaction has excellent anti-flammability, thermal stability, prevents The advantages that aqueous and good mechanical performance, is widely used in industrial various aspects.In leather industry, melamine Resin can be used as retanning agent, filler, pretanning agent etc., have apparent effect to grain side of leather and finished leather exquisiteness is improved；In optics Material using upper, melamine resin has excellent thermal stability, insulating properties and etch resistance；In foam material field, Melamine resin foam has many advantages, such as that excellent sound-absorbing, heat-insulating property, fire-retardant, high temperature resistant, density are low and wear-resistant；It is molding Expect industry, melamine resin product has many advantages, such as various colors, good insulating, anti-pollution, high temperature resistant, fire-retardant；In papermaking Wet strength, folding strength, wearability and dimensional stability of paper etc. can be improved in industry, melamine resin wet strength agent；In wood Material industrial circle, melamine resin are a kind of more important amino resins gluing agent, have very high glue-joint strength, higher Resistance to ability of endurance boiling water, thermal stability is high, and low-temperature setting ability is stronger, and hardness is high, and wearability is excellent, is plate for timber-construction gluing The hot spot of agent development and application.

The main problem of melamine resin is that free formaldehyde content is higher and toughness is poor, and presently relevant research is main Concentrate on the latter.Melamine resin cured layer brittleness is larger and impact resistance ability is poor, which greatly limits The use scope of product, and influence it and use quality.Traditional theory thinks, the melamine resin intramolecular network after solidification Chain is shorter, and crosslink density is higher, and steric hindrance is larger, is unfavorable for the generation of strain when by external force, absorbs impact energy Ability decline, and the triazine ring in melamine molecule is a kind of structure similar to the heterocycle of aromatic ring, steric hindrance is larger, have compared with Big rigidity, so that the flexibility of melamine resin is poor.In addition, there is the hydroxyl first for having neither part nor lot in reaction in cured resin Base causes melamine resin with hygroscopicity to a certain degree, and by the variation of ambient humidity, resin is continually because moisture absorption is conciliate It inhales and generates stress and fatigue, finally also result in brittle generation.

For the problem that melamine resin brittleness is larger, the solution of most study is to reduce melamine resin Crosslink density, according to the combination of molecular resin and modifying agent, the toughening modifying of melamine resin can be divided into physical method Toughening and chemical method toughening.Physical method toughening refers in the addition blending and modifying agent of melamine resin reaction later period, can be with Play the role of physical barrier, prevents triazine ring close to each other.There is no change between modifying agent and melamine resin macromolecular Learn the generation of key, such as cellulose powder, starch, polyvinyl acetate emulsion and polyvinyl alcohol.Currently, related melamine resin increases Tough research is concentrated mainly on chemical method toughening, be make modifying agent and melamine resin polycondensation monomer, reaction intermediate it Between occur chemical bond combination, change between each structure of resin link sequence distribution and molecular structure, increase triazine ring it Between distance, reduce crosslink density, mention Polymer chain flexibility, increase impact strength, bending strength and toughness.According to modifying agent The mode of action between triazine ring can be divided into flexible chain extended type and functional group's shield type.Flexible chain modifying agent is generally more Degree of functionality substance, such as trimethylolpropane, glycerine, polyethylene glycol, such modifying agent pass through one of functional group and three Methylol on piperazine ring or amino connection, remaining functional group on other triazine rings methylol or amino connect, functional group it Between flexible chain link triazine ring, make strand that there is bigger intramolecular deformability than the strand that is connected by methylene And lower resin crosslink density, to improve resin flexibility.It is all Monofunctional reagents that functional group, which shields modifying agent, such as Para toluene sulfonamide, thiocarbamide, chitosan etc., such modifying agent shield an amino on triazine ring, reduce by a crosslinking Point, so that realizing reduces melamine resin crosslink density purpose.Traditional method of modifying does not consider melamine fundamentally Where resin brittleness Producing reason, not from the point of view of molecular structure, basic point of departure is only limitted to addition and is modified, and draws Into flexible material, increase intramolecular network chain length, the degree of cross linking for reducing molecular resin etc..Although the increasing about melamine resin Tough modification has numerous studies report, such as:

1, patent application CN201210353513.1 discloses a kind of toughening modifying method of melamine resin. Use the compound for containing polyhydroxy, more carboxyls, any one or two kinds in polyamino as toughener, with methylol trimerization Cyanamide carries out polycondensation reaction, and flexible-chain polymer is introduced in melamine resin, reduces cross-linkage of resin, improves it Flexibility.The elongation at break of melamine resin after toughening is increased to 89.3% by original 6.3%.It is of the invention public The toughening modifying method for the melamine resin opened, solving the melamine resin of the prior art, there are brittleness Greatly, the problems such as flexibility is poor, the easy chip off-falling of resin, preparation process is complicated, is with a wide range of applications.

2, patent application CN201710553436.7 discloses a kind of polyol ethers toughening modifying melamine-formaldehyde-urine The method of plain copolycondensation adhesive, it is polynary including polyol ethers toughening modifying melamine-formaldehyde-urea copolycondensation adhesive Alcohol ether additive amount, order of addition and preparation method, wherein polyol ethers content is the 1-8%wt of gluing agent content.Benefit of the invention Use the polyol ethers with alcohol ether structure as modifying agent, with reduce the degree of cross linking between melamine-formaldehyde-urea molecule and Increase the ratio of soft segment in molecule, improve glue-line toughness, glued board impact strength improves 20% or more, and elasticity modulus improves 30% or more, Storage period raising 3 days or more.Adhesive produced by the present invention has raw material sources extensive, cheap, preparation side Method is easy, and Technological adaptability is good, toughening effect is significant and glued board has the significant advantages such as high impact resistance.

3, patent application CN201811379719.5 discloses a kind of urea and melamine activeness and quietness graphene oxide Phenol-formaldehyde resin modified foam, it is characterised in that the foam is by graphene oxide phenol-formaldehyde resin modified, Lauxite, melamine 3 part of formaldehyde resin composition.Wherein, it is 95~100 parts that the graphene oxide phenol-formaldehyde resin modified, which includes by components by weight percent, Phenolic resin and 1~8 part of graphene oxide composition；The phenolic resin in-situ polymerization is grown on graphene oxide active site On, and by graphene oxide partial reduction；The graphene oxide number of plies is 1~5 layer, 20~60 μm of diameter；The oxidation stone Black alkene phenol-formaldehyde resin modified, Lauxite and melamine resin form homogeneous blend.Usefulness of the present invention are as follows: (1) excellent fireproof performance；(2) the scaling-off performance of anti-powdering improves.

But document disclosed above and other in the prior art, the effect of melamine resin toughening is still paid no attention to Think.Studies have shown that there are a kind of more stable methylene ether bond structures lower than bridged bond energy in melamine resin system, i.e., There are two triazine anchor ring face parallel folds structures in the turn conformation of methylene ether link in melamine triazine ring, due to two Triazine ring is the big pi bond structure of conjugation, and two interannulars just produce pi-pi accumulation effect, so that system is more stable.In other words, If this pi bond Supramolecular self assembly foldable structure can be formed in melamine resin, theoretically entire molecular resin will picture A piece spring, this " spring " structure can make the macro-mechanical property of melamine resin, curing performance etc. take on a new look, and And melamine resin has excellent flexibility.Therefore, a kind of Supramolecular self assembly toughening modifying melamine tree is developed The method of rouge is particularly important.

Summary of the invention

The present invention is in order to solve the above technical problems, provide a kind of Supramolecular self assembly toughening modifying melamine resin Preparation method and application.The application sets about from spatial configuration of molecules, carries out surface to kaolinite first and is modified, modified using surface Kaolinite and melamine molecule form supermolecule and accumulate system, are mainly deposited in melamine by triazine ring π-π supermolecule Constructing in resin guarantees that melamine resin is stratiform supermolecule packed structures during formation, to realize to three The toughening of cymel, for toughness amplification 250~400%, free formaldehyde content is lower, and the formaldehyde of elimination is mostly with methylene bridge There are resin systems for the form of key, and stability is higher than ehter bond, and mechanical property with higher and heat resistance.

In order to reach purpose described above, the invention adopts the following technical scheme:

A kind of preparation method of Supramolecular self assembly toughening modifying melamine resin, the preparation method include that surface changes Property it is kaolinic preparation and toughening modifying melamine resin preparation, the surface change it is kaolinic preparation is: using ultrasound Disperse kaolinite is evenly dispersed in deionized water, then be added surface modifier stir evenly, then through constant temperature handle, from The heart, washing, drying obtain surface modified kaolinite；The preparation of toughening modifying melamine resin is: using ultrasonic disperse by table Face modified kaolinite and paraformaldehyde are evenly dispersed in organic solvent, melamine are added after adjusting pH value, after mixing evenly Isothermal holding, then through cooling, adjusting pH value, the Supramolecular self assembly toughening modifying melamine resin is made.

Further, the preparation method of the Supramolecular self assembly toughening modifying melamine resin, including following step It is rapid:

(1) preparation of surface modified kaolinite

Kaolinite and surface modifier are weighed according to parts by weight, kaolinite is placed in deionized water, pass through ultrasound point It dissipates uniformly, then adds surface modifier, after mixing evenly, water bath with thermostatic control is heated and stirred, and centrifugation is washed with deionized It is dry to constant weight after 2~3 times, obtain surface modified kaolinite；

(2) preparation of toughening modifying melamine resin

The surface modified kaolinite and paraformaldehyde that step (1) is obtained are added in organic solvent, ultrasonic disperse processing, so PH value is adjusted to 8.5~9.0 with NaOH solution afterwards, melamine is added, stirs evenly, after heating and isothermal holding, when going out When existing white flock precipitate, stops reaction and material is cooled to 40 DEG C, adjust pH value to 9.0, obtain the supermolecule from group Fill toughening modifying melamine resin.

Further, in step (1), the temperature of the water bath with thermostatic control is 85~90 DEG C, the time being stirred to react is 7.5~ 9h；The temperature of the drying is 105~130 DEG C；The revolving speed of the centrifugation is 3500~4500r/min.

Further, in step (2), the mass concentration of the NaOH solution is 30%；The temperature of the isothermal holding is 85~90 DEG C, the time is 12~18h, and pH value control is 8.5~9.0 when insulation reaction.

Further, in step (1) and step (2), the frequency of the ultrasonic disperse is 25~35KHz, the time is 20~ 30min。

Further, the kaolinite, organic solvent, surface modifier, paraformaldehyde and melamine are according to following heavy Amount part is matched: 5~15 parts of kaolinite, 135~165 parts of organic solvent, 2~6 parts of surface modifier, paraformaldehyde 100~ 150 parts, 40~80 parts of melamine.

Further, the organic solvent is benzene, in toluene, acetone, chloroform, dimethyl sulfoxide, triethanolamine, styrene One or more.

Further, the surface modifier is neopelex, lauryl sodium sulfate, dodecyl front three Base ammonium bromide, cetyl trimethylammonium bromide, trimethylolpropane, Silane coupling agent KH550, two kinds in acidic ionic liquid Or it is two or more.

Further, Supramolecular self assembly toughening modifying melamine tree made from a kind of preparation method as described above Rouge, the performance indicator of the Supramolecular self assembly toughening modifying melamine resin are as follows: free formaldehyde content is lower, mechanical property It is higher with heat resistance, and toughness is remarkably improved, toughness amplification is 250~400%.

Further, the application of the Supramolecular self assembly toughening modifying melamine resin, be applied to leather industry, In optical material, foamed material, moulding compound, paper industry, timber industry and other industrial productions, there is free formaldehyde content Feature low, toughness is strong.

The application principle: as shown in Figure 1, kaolinite used herein is in stratiform or laminated structure, by two silicon oxygen four Face body is mingled with an alumina octahedral and piles up, and has unique " sandwich " sandwich.After the activated processing of kaolinite, Surface generates a large amount of active group, dispersibility and the compatibility enhancing of one side kaolinite and system, another aspect kaolinite The active group on surface can be in conjunction with formaldehyde, melamine, melamine methylol, in the effect of organic solvent and ultrasound Under, so that melamine resin is stratiform supermolecule packed structures during formation.At this moment entire melamine resin exists A similar spring on molecular structure, this " spring " structure can make melamine resin have excellent flexibility, and The melamine resin free formaldehyde content of acquisition is lower, and macro-mechanical property and heat resistance will not reduce.

Since present invention employs above technical schemes, have the advantages that

(1) conventional method does not consider melamine resin brittleness Producing reason institute fundamentally to the modification of melamine , not from the point of view of molecular structure, basic point of departure be only limitted to addition be modified, introduce flexible material, increase molecule Interior network chain length, the degree of cross linking for reducing molecular resin etc.；And the application sets about from spatial configuration of molecules, carries out first to kaolinite Surface is modified, forms supermolecule using surface modified kaolinite and melamine molecule and accumulates system, mainly passes through triazine ring π-π Supermolecule is deposited in constructing in melamine resin, guarantees that melamine resin is stratiform supermolecule heap during formation Product structure, to realize the toughening to melamine resin.

(2) conventional method is to the modification of melamine resin often to sacrifice the intensity of melamine resin itself or heat-resisting Property be cost the toughness that exchanges melamine resin for；And the mechanics with higher of melamine resin made from the application method Performance and heat resistance, while the toughness of melamine resin is remarkably improved, toughness amplification is 250~400%.

(3) tradition adds modified method to melamine resin free formaldehyde energy decrease to some degree, but this Kind method is more to be transformed into ehter bond latching inside resin formaldehyde, gives a kind of " illusion " for reducing free formaldehyde of people.In fact, In In the use process in later period, these formaldehyde, which once encounter hydro-thermal, to be come out by slow release.The melamine of the application preparation Resin free formaldehyde content is lower, and for the formaldehyde of elimination there are resin system mostly in the form of methylene bridged bond, stability compares ether Key is high.

Detailed description of the invention

In order to illustrate more clearly of present example or technical solution in the prior art, to embodiment or will show below There is in technical description required attached drawing do simply to introduce, it should be apparent that, the accompanying drawings in the following description is only the present invention Some examples to those skilled in the art, can also be attached according to these under the premise of not paying creativeness Figure obtains other attached drawings:

Fig. 1 is the application melamine resin self assembly toughening mechanism.

Specific embodiment

Specific embodiments of the present invention will be described in further detail below, but the invention is not limited to these realities Mode is applied, it is claimed to still fall within the claims in the present invention for any improvement or replacement on the present embodiment essence spirit Range.