Nylon claims polymeric amide again, has excellent physical and mechanical performance, monomer cast nylon particularly, and because of high nearly one times of the common nylon of molecular weight ratio, performance is more superior.But, since the effect of acid amides polarity gene, the water-intake rate height of nylon, and heat-resisting ageing-resisting is poor.Adopt the mineral filler modification of nylon, for example: with molybdenumdisulphide, graphite-filled nylon, can improve the wear resistance and the self-lubricating ability of nylon, but cost rising strength degradation; Adopt lime carbonate, potter's clay etc., can reduce the cost of nylon, improve rigidity, but intensity and toughness descend.In order to overcome above-mentioned directly filling-modified defective, adopt ultra-fine inorganic thing surface parcel coupling agent treatment, affinity, the consistency of filler and nylon are greatly improved, modified effect increases substantially, because chemical structure, the physical condition difference of filler and nylon are too big, still can not eliminate the surface tension of filler and nylon fully, not reach ideal dispersion and bonding, influence the improvement of reinforced effects and other performances.
Chinese patent 961053623, report in-situ inserted polymerization process and prepared nanometer composite polyamide-clay material, be cationic exchange, monomer of polyamide intercalation, cationic ring-opening polymerization disposable the finishing in reactor with the clay seam crack, the preparation clay is with the homodisperse high performance composite of nanoscale.But still have following deficiency: in preparation process, used a large amount of dispersion medium, removed these dispersion medium and need consume a large amount of energy and time; (2) polymerization time is long, needs the polymerization of 6-10 hour ability to finish, and also up to 250 ℃-260 ℃, during energy charge, efficient is low, the cost height for polymerization temperature.(3) intensity is about 98MPa, and heat-drawn wire is lower than 160 ℃, still can not satisfy the requirement of strength of industrial important accessory, massive article.
Mineral filler disperses inequality in the prior art in nylon base in order to overcome, and reinforced effects is poor, and the high deficiency of in-situ inserted cationic polymerization cost, the invention provides the more excellent nylon/bentonite nano composite material of a kind of performance.
The present invention is the sheet crack layer by layer that nylon monomer is inserted into wilkinite silicate, carries out anionic polymerisation, makes nylon/bentonite nano composite material and cast product thereof.Wherein the silicate lamella is made disperse phase, and excellent mechanical property and thermal characteristics is provided; Nylon is made external phase, has guaranteed good processing properties.Adopt the intercalant anion polymerization process to prepare the inorganic organic nano matrix material, give material many excellent properties, and cost does not almost increase than traditional blend method, its application prospect is very wide.
Nylon/bentonite nano composite material of the present invention, feed composition and content (weight part) are as follows:
Nylon monomer 100
Wilkinite 0.03-40
Catalyzer 0.01-5
Intercalator 0.01-15
Additive 0.1-10
The nylon monomer that the present invention was suitable for is a lactams, as: hexanolactam, spicy inner formyl amine, laurolactam, butyrolactam etc.When the preparation nylon/bentonite nano composite material, can select a kind of monomer for use, also can select several monomers for use, to mix and use, its purity is industrial-grade monomer.
Wilkinite provided by the present invention is the silicate of a class laminated structure, and major ingredient is the montmorillonite stratiform mineral substance that contains more than 70%, and its sheet bed thickness is about 1nm, and the sheet lamellar spacing is about 2nm, interlayer cation K
+, Na
+, Ca
2+, Mg
2+Deng being the interchangeability positively charged ion, after the ammonium salt exchange, can make nylon monomer be inserted into interlayer.The bentonite ore material should have cationic exchange total amount 70-100mmol/100g.When exchanging total amount greater than 100mmol/100g, the interlayer Coulomb's force is too big, and bentonite lamella is difficult for intercalation and opens, do not realize being scattered in the nylon with nano level, when exchange capacity less than 70mmol/100g, wilkinite and nylon monomer effect are little, consistency is poor, the same inequality of disperseing.
Bentonite content among the present invention is 0.03-40 part (weight part) and need be broken for the 200-800 order that when consumption was lower than 0.03 part, modified effect was not obvious.When content was higher than 40 parts, feed concentration was too big in the preparation process, produced difficulty, and best bentonite content is 15 parts.
The catalyzer that the present invention is suitable for is alkali catalyst and promotor.Alkali catalyst is sodium Metal 99.5 or potassium metal or metallic lithium or sodium hydroxide or potassium hydroxide or yellow soda ash or sodium alkoxide; Promotor is the ethanoyl hexanolactam, or various isocyanic ester or acid anhydrides or acyl chlorides.The hydrogen ion that the metal ion of alkali catalyst replaces nylon monomer makes monomer become negatively charged ion, generation anionic catalytic polymerization reaction, under the effect of promotor, this speed of response becomes hundred times of ground to improve, react desired activation energy and reduce significantly, about 150 ℃, finished polyreaction usually through 10-40 minute.Catalyst levels among the present invention is 0.01-5, and wherein alkali catalyst and promotor equivalent use.
The intercalator that the present invention adopts is an ammonium salt class material, can make cationic exchange between bentonite bed and makes between the nylon monomer embeding layer.Its consumption is 0.01-15 part (weight part).
Additive of the present invention is anti-aging agent, lubricant, toughner, toner, nucleator, dispersion agent etc., and its effect is control crystallization of nylon and molecular structure etc., improves the ageing-resistant performance, lubricity of matrix material etc.Additive can use separately or be used.
Nylon/bentonite nano composite material production technique of the present invention is: after earlier wilkinite 0.03-50 part, intercalator 0.01-15 part being mixed, with 100 parts of addings of nylon monomer, under action of ultrasonic waves, carry out cationic exchange and monomer intercalation.Meanwhile, after carrying out vacuum distilling dehydration for some time, adding alkali catalyst 0.01-2 part continues to dewater, to water content less than 300ppm, the promotor that adds with the catalyzer equivalent mixes in the mould that waters into about 180 ℃ of preheatings rapidly, promptly gets the cast product of matrix material in polymerization 10-40 minute; The reactor that also can water about 240 ℃ of into preheatings obtained nylon/bentonite nano composite material in interior polymerization 10-14 minute, took out granulation.
Nylon monomer of the present invention is under the help of intercalator, can insert the bentonite bed crack, and can make a layer inside and outside monomer generation anionic ring-opening polymerization generate macromole, the heat that is produced by reaction makes bentonite lamella enlarge, open even is broken apart, the silicate lamella is disperseed with nanoscale, obtain nylon/bentonite nano composite material or its cast product.With the common production method and the single stage method comparison of China's patent report, nylon base molecular weight height, material and product properties are good.
Nylon/bentonite nano composite material of the present invention, the wilkinite disperse phase reaches 20-80nm, have very large interface and activity, inorganic have desired binding with organic phase, can eliminate the mismatch problem that inorganics and organic polymer bring because of the difference of chemical structure, physical condition, give full play to inorganics and organism intrinsic excellent properties and synergistic effect, give the performance of matrix material excellence, its intensity generally surpasses about 50% of same type of material.
Polymerization has nucleogenesis and the effect of the brilliant bag growth of slowing down to nylon monomer for bentonite nano particulate of the present invention, promotor, thereby the nylon base lattice is fine and closely woven, gives material high-strength wearable performance.
Example 1
With the 2g wilkinite, quaternary ammonium salt 0.4 gram mixes, mixes with 80 ℃ hexanolactam liquation, and intercalation under the ultrasonic wave effect, and 80 ℃ of maintenances 40 minutes.Be decompressed to-continue heating up under the 0.095MPa vacuum condition 135 ℃ of distillation dehydrations 10 minutes, add catalyzer sodium hydroxide 0.4 gram and continue vacuum hydro-extraction about 10 minutes, make water-content less than 300ppm, obtain containing the mixed solution of hexanolactam negatively charged ion and wilkinite intercalation.Add promotor TDI 0.8 gram again, the in-site polymerization 30 minutes that stirs and water into about 180 ℃ of preheatings rapidly, the cast product of nylon/bentonite matrix material.These goods are observed through atomic force microscope, show that the bentonite clay particle diameter is 58nm, and be dispersed in the nylon base that its mechanical property sees Table 1.
Example 2-4
Technology is with example 1, and wherein bentonite content is respectively 5g, 10g, its mechanical property of 15g sees Table 1.Increased by the visible bentonite content of table, the intensity resistance toheat improves.
Example 5-8
With example 1, wherein catalyzer sodium hydroxide is that 0.6g, 0.8g and promotor TDI 1 gram, 1.5 restrain its reaction times and mechanical property such as table 2.
Table 1
Example |
Bentonite content (gram) |
Quaternary ammonium salt (gram) |
Tensile strength (MPa) |
Extension at break (%) |
Thermal change type temperature (℃, 18.6kg/cm
2)
|
Molecular-weight average (10
4)
|
Wilkinite particle diameter (nm) |
Caprolactam content (gram) |
1 |
2 |
0.4 |
94 |
21 |
170 |
7.4 |
58 |
100 |
2 |
5 |
1 |
115 |
20 |
176 |
7.2 |
59 |
100 |
3 |
10 |
2 |
148 |
17 |
184 |
7 |
59 |
100 |
4 |
15 |
3 |
165 |
10 |
190 |
6.9 |
61 |
100 |
Table 2
Example |
Sodium hydroxide (gram) |
TDI (gram) |
Tensile strength (MPa) |
Extension at break (%) |
Thermal change type temperature (℃, 18.6kg/cm
2)
|
Molecular-weight average (10
4 )
|
Wilkinite particle diameter (nm) |
Reaction times (minute) |
5 |
0.6 |
0 |
90 |
24 |
165 |
9.5 |
58 |
480 |
6 |
0.6 |
1 |
86 |
21 |
170 |
7.0 |
58 |
20 |
7 |
0.8 |
1 |
84 |
21 |
170 |
7.0 |
58 |
20 |
8 |
0.8 |
1.5 |
70 |
16 |
172 |
5.6 |
68 |
12 |
Example 9-12
With example 1, wherein the intercalator quaternary ammonium salt is 0.2,0.6,0.8,1 gram, wilkinite particle diameter and mechanical property such as table 3.
Table 3
Example |
Quaternary ammonium salt (gram) |
Wilkinite particle diameter (nm) |
Tensile strength (MPa) |
Extension at break (%) |
Thermal change type temperature (℃, 18.6kg/cm
2)
|
Molecular-weight average (10
4)
|
9 |
0.2 |
80-5000 |
84 |
20 |
158 |
6.9 |
10 |
0.6 |
58 |
95 |
19 |
170 |
7 |
11 |
0.8 |
58 |
94 |
18 |
170 |
6.9 |
12 |
1 |
58 |
93 |
18 |
170 |
6.9 |