The preparation method and preparation system of a kind of high polymerization degree narrow ditribution polyvinyl alcohol
Technical field
The invention belongs to polyvinyl alcohol technical field, more particularly to a kind of preparation side of high polymerization degree narrow ditribution polyvinyl alcohol
Method and preparation system.
Background technology
Polyvinyl alcohol (hereinafter referred to as PVA) is a kind of macromolecular compound, and it has been widely used in the industry.Many institute's weeks
The PVA polymerizations known have polymerisation in solution, polymerisation in bulk, suspension polymerisation, emulsion polymerization etc., and polymerisation can use organic peroxy
Class, azo, persulfuric acid salt etc. prepare polyvinyl acetate (hereinafter referred to as PVAc) as initiator, will by saponification
PVAc is converted into PVA.
Current PVA industrialized productions mainly use solution polymerization process, but the PVA degree of polymerization not more than 3000 for obtaining,
The PVA of high polymerization degree can not be prepared, and high polymerization degree PVA is only the ideal material for preparing film and high-performance fiber.
Japanese Patent Laid-Open No. Sho 61-148209/1986 discloses the side that a kind of use suspension polymerisation prepares high polymerization degree PVA
Method, the method polymerization temperature is below 20 DEG C, and polymerization time is long more than 48 hours, it is difficult to realize industrialization.
Chinese Journal of Synthetic Chemistry, 14 (3), 253-257,2006 discloses the vinegar of report
Vinyl acetate (hereinafter referred to as VAc) suspension polymerization, is typically employed in VAc and dissolves initiator, and VAc is molten with initiator
Liquid adds suspension polymerisation is carried out in reactor simultaneously, and which can be sent out in initiator dissolving tank and delivery pipe in industrializing amplification
Biology material autohemagglutination plugging problem, affects greatly to industrializing continuous production.Therefore so far, PVA is prepared for suspension polymerisation
Report be only limitted to laboratory research, be difficult realize industrialization.
The content of the invention
In view of this, the technical problem to be solved in the present invention is to provide a kind of system of high polymerization degree narrow ditribution polyvinyl alcohol
Preparation Method and preparation system.
The invention provides a kind of preparation method of high polymerization degree narrow ditribution polyvinyl alcohol, including:
S1) polymerized monomer, initiator are mixed with organic solvent in static mixer, mixed liquor is obtained;The polymerization
Monomer includes vinylacetate;
S2) mixed liquor is mixed with desalted water, under anaerobic airtight condition, polymerisation is carried out, poly-vinegar acid is obtained
Vinyl acetate;
S3 the polyvinyl acetate) is carried out into saponification, polyvinyl alcohol is obtained.
Preferably, counted by 100 weight portions of polymerized monomer, the desalted water is 100~300 weight portions, the initiator
It is 0.01~0.3 weight portion, the organic solvent is 0.01~10 weight portion.
Preferably, the initiator be 50 DEG C of half-life period be 20~900min organic peroxy class initiator and/or 50 DEG C
Half-life period is the azo-initiator of 20~900min.
Preferably, the initiator is selected from peroxy dicarbonate double (4- tert-butylcyclohexyls) ester, peroxidating neodecanoic acid -2,
In 4,4- trimethyls pentyl ester, cumyl peroxyneodecanoate, peroxidating cyclohexylsulfonyl acetyl and ABVN one
Plant or various.
Preferably, the organic solvent is selected from low chain tra nsfer, the fatty alcohol of low-molecular-weight, low chain tra nsfer, low-molecular-weight
One or more in aliphatic hydrocarbon and low chain tra nsfer, the aromatic compound of low-molecular-weight;It is preferably selected from methyl alcohol, ethanol, tertiary fourth
One or more in alcohol, benzene and toluene.
Preferably, the temperature of the polymerisation is 25 DEG C~50 DEG C;The time of polymerisation is 3~6h.
Preferably, the step S1) it is specially:
Initiator is mixed with organic solvent, initiator solution is obtained;
The initiator solution is mixed with polymerized monomer in static mixer, mixed liquor is obtained.
Preferably, the step S2) in desalted water is first heated to 40 DEG C~90 DEG C, then mix with mixed liquor again.
Preferably, the static mixer is selected from SV types static mixer, SK types static mixer or SX static mixings
Device..
Present invention also offers a kind of preparation system of high polymerization degree narrow ditribution polyvinyl alcohol, including:
Polymerization reaction kettle;The polymerization reaction kettle is provided with desalted water charge door, second charging aperture and discharging opening;
The static mixer being connected with the second charging aperture of the polymerization reaction kettle;The static mixer is provided with poly-
Close monomer addition mouthful and initiator charge door;
The scrubbing tower being connected with the discharging opening of the polymerization reaction kettle;
The saponification device being connected with the discharging opening of the scrubbing tower.
The invention provides a kind of preparation method of high polymerization degree narrow ditribution polyvinyl alcohol, including:S1) by polymerized monomer,
Initiator mixes with organic solvent in static mixer, obtains mixed liquor;The polymerized monomer includes vinylacetate;S2)
The mixed liquor is mixed with desalted water, under anaerobic airtight condition, polymerisation is carried out, polyvinyl acetate is obtained;S3) will
The polyvinyl acetate carries out saponification, obtains polyvinyl alcohol.Compared with prior art, the present invention first through vinylacetate with draw
After hair agent is well mixed in the static mixer, then mix with desalted water and carries out suspension polymerisation, so as to get polyvinyl alcohol be polymerized
Spend higher and narrowly distributing;And preparation method of the invention has, and polymerization time is short, speed is fast, synthesis technique is simple, operation side
Just, pipeline is not likely to produce the advantage of monomer autohemagglutination, is suitable to industrialization, and the polyvinyl alcohol for preparing is applicable to produce polyethylene
The application fields such as alcohol polaroid, high strength and modulus vinal, with wide market prospects.
Brief description of the drawings
Fig. 1 is the structural representation of the preparation system of the high polymerization degree narrow ditribution polyvinyl alcohol that the present invention is provided.
Specific embodiment
Below in conjunction with the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described,
Obviously, described embodiment is only a part of embodiment of the invention, rather than whole embodiments.Based in the present invention
Embodiment, the every other embodiment that those of ordinary skill in the art are obtained under the premise of creative work is not made, all
Belong to the scope of protection of the invention.
The invention provides a kind of preparation method of high polymerization degree narrow ditribution polyvinyl alcohol, including:S1) by polymerized monomer,
Initiator mixes with organic solvent in static mixer, obtains mixed liquor;The polymerized monomer includes vinylacetate
(VAc);S2) mixed liquor is mixed with desalted water, under anaerobic airtight condition, polymerisation is carried out, poly-vinegar acid second is obtained
Alkene ester;S3 the polyvinyl acetate) is carried out into saponification, polyvinyl alcohol is obtained.
Wherein, the present invention is not particularly limited to the source of all raw materials, is commercially available.The polymerized monomer bag
Vinylacetate is included, may also comprise other can be with one or more in vinyl acetate copolymerized monomer;In the present invention, with
Polymerized monomer is 100 weight portion meters, and the desalted water is preferably 100~300 weight portions, more preferably 150~250 weight portions,
It is further preferably 200 weight portions;The initiator is preferably 0.01~0.3 weight portion, more preferably 0.05~0.2 weight portion, then
Preferably 0.1~0.15 weight portion, most preferably 0.1 weight portion;The species of the initiator is known for those skilled in the art
Initiator, have no special limitation, the organic peroxy class that 50 DEG C of half-life period are 20~900min is preferably in the present invention
Initiator and/or 50 DEG C of half-life period are the azo-initiator of 60~600min, more preferably 50 DEG C half-life period are 60~
The organic peroxy class initiator of 600min and/or 50 DEG C of half-life period are the azo-initiator of 20~900min;Organic mistake
Oxygen class initiator is preferably peroxy dicarbonate double (4- tert-butylcyclohexyls) ester, peroxidating neodecanoic acid -2,4,4- trimethyls penta
One or more in ester, cumyl peroxyneodecanoate and peroxidating cyclohexylsulfonyl acetyl;The azo-initiator
Preferably ABVN;The organic solvent is preferably 0.01~10 weight portion, more preferably 0.45~5 weight portion, then
Preferably 0.45~3 weight portion, most preferably 0.45~1 weight portion;The organic solvent is well known to those skilled in the art
Organic solvent, has no special limitation, is preferably low chain tra nsfer, the fatty alcohol of low-molecular-weight in the present invention, low chain tra nsfer,
One or more in the aliphatic hydrocarbon of low-molecular-weight and low chain tra nsfer, the aromatic compound of low-molecular-weight, more preferably methyl alcohol,
One or more in ethanol, the tert-butyl alcohol, benzene and toluene is further preferably methyl alcohol, one or more in benzene and the tert-butyl alcohol.
Polymerized monomer, initiator are mixed with organic solvent in static mixer, mixed liquor is obtained;It is excellent in the present invention
Choosing first mixes initiator with organic solvent, obtains initiator solution;Then again by initiator solution and polymerized monomer in static state
Mix in blender;The initiator mixes with organic solvent preferably to be carried out under low-temperature protection;The initiator solution with it is poly-
The time that conjunction monomer mixes in static mixer is preferably 1~20s.In the present invention preferably simultaneously by polymerized monomer and initiation
Agent solution is passed through in static mixer, and the feed time of polymerized monomer need to be matched and identical with the feed time of initiator solution,
Adoptable mode sets atomising device as reduced initiator solution inlet amount at outlet nozzle, to increase polymerized monomer
With the mixture homogeneity of initiator solution so that improve production efficiency, while meeting the safety factor of operation.It is described static mixed
Clutch is static mixer well known to those skilled in the art, has no special limitation, SV types is preferably in the present invention quiet
State blender, SK types static mixer or SX static mixers, more preferably SV types static mixer.
The mixed liquor is mixed with desalted water;Preferably first desalted water is heated in the present invention, i.e., in hot feed mode
Add, to shorten polymerization time;It is preferred that desalted water is heated into 40 DEG C~90 DEG C, 60 DEG C~90 DEG C are more preferably heated to,
70 DEG C~90 DEG C are further preferably heated to, 80 DEG C is most preferably heated to, then mix with mixed liquor.The mixing is preferably in polymerisation
Carried out in kettle, to reduce the polymerized monomer and initiator in mixed liquor, it is preferred to use a small amount of desalted water rinses static mixer, will
It is also added in reaction system.
According to the present invention, preferably can also on demand add various additives in reaction system, such as suspending agent, polymerization regulator,
One or more in polymerization inhibitor, pH value regulator, scale preventative and defoamer;The suspending agent is known for those skilled in the art
Suspending agent, have no special limitation, its can be dispersant, surfactant or polyvinyl alcohol water solution, preferably gather
Vinyl alcohol aqueous solution;The concentration of the polyvinyl alcohol water solution is preferably 5%~20%, more preferably 5%~15%, further preferably
It is 10%;The degree of polymerization of the polyvinyl alcohol is preferably 1000~2500, more preferably 1500~2000, is further preferably 1700;
The alcoholysis degree of the polyvinyl alcohol is preferably 70%~90% (mole), more preferably 80%~90% (mole), further preferably for
88% (mole);Counted by 100 weight portions of polymerized monomer, the amount of the suspending agent is preferably 0.01~10 weight portion, more preferably
It is 0.05~5 weight portion, is further preferably 0.5~3 weight portion, most preferably 1~2 weight portion;Suspending agent can make polymerized monomer equal
It is even to be dispersed in reaction system.The polymerization regulator is polymerization regulator well known to those skilled in the art, has no spy
Different limitation, is preferably one or more in acetaldehyde, butyraldehyde and mercaptan in the present invention;Counted by 100 weight portions of polymerized monomer,
The amount of the polymerization regulator is preferably 0.01~10 weight portion, and more preferably 0.05~5 weight portion is further preferably 0.5~3 weight
Amount part, most preferably 1~2 weight portion;The polymerization inhibitor is polymerization inhibitor well known to those skilled in the art, and it is special to have no
Limitation, is preferably the one kind or many in phenolic compound, sulfur-containing compound and the oxide-based compound polymerization inhibitors of N- in the present invention
Kind;The pH value regulator is pH value regulator well known to those skilled in the art, special limitation is had no, in the present invention
Preferably sodium acid carbonate;Counted by 100 weight portions of polymerized monomer, the amount of the pH value regulator is preferably 0.01~10 weight
Part, more preferably 0.05~5 weight portion is further preferably 0.1~3 weight portion, is further preferably 0.5~1 weight portion, most preferably
0.5 weight portion.
After mixing, under anaerobic airtight condition, polymerisation is carried out;The condition of the polymerisation is people in the art
Polymeric reaction condition known to member, has no special limitation, and the temperature of heretofore described polymerisation is preferably 25 DEG C
~50 DEG C;The time of the polymerisation is preferably 3~6h.
After reaction terminates, preferably after use desalination water washing, dehydration, drying, polyvinyl acetate is obtained.
The polyvinyl acetate is carried out into saponification;The method of the saponification is for method well known to those skilled in the art
Can, have no special limitation, be preferably in the present invention by polyvinyl acetate in the methanol solution containing alkali at 5 DEG C~60 DEG C
Alcoholysis is no less than 1.5h.The content of alkali is preferably the 0.5%~3% of polyvinyl acetate quality in the methanol solution, more excellent
Elect 1%~2% as, be further preferably 1%;The temperature of the saponification is preferably 10 DEG C~60 DEG C, more preferably 30 DEG C~60 DEG C, then
Preferably 40 DEG C~60 DEG C, most preferably 60 DEG C;The time of the saponification is preferably 1~3h, more preferably 2h.
After saponification, preferably it is dried, obtains polyvinyl alcohol;The dry temperature is preferably 70 DEG C~90 DEG C, more excellent
Elect 80 DEG C as;The dry time is preferably 1~5h, more preferably 1~3h, is further preferably 2h.
After the present invention is first well mixed with initiator through vinylacetate in static mixer, then it is mixed into desalted water
Row suspension polymerisation, so as to get the polyvinyl alcohol degree of polymerization is higher and narrowly distributing;And when preparation method of the invention has polymerization
Between short, speed is fast, synthesis technique is simple and convenient to operate, pipeline is not likely to produce the advantage of monomer autohemagglutination, be suitable to industrialization, prepare
The polyvinyl alcohol for obtaining is applicable to the application fields such as production polyvinyl alcohol polaroid, high strength and modulus vinal,
With wide market prospects.
Present invention also offers polyvinyl alcohol prepared by a kind of above method;The degree of polymerization of the polyvinyl alcohol is preferably
1000~30000, more preferably 2000~20000, it is further preferably 3000~10000;The decentralization of the polyvinyl alcohol is preferred
It is 1.3~1.8.It is equal that the degree of polymerization in the present invention refers to that the polyvinyl alcohol (PVA) obtained by polyvinyl acetate (PVAc) saponification glues
The degree of polymerization, the PVAc obtained from the present invention can obtain fully saponified or partly-hydrolysed product, PVA saponification degrees can 60%~
99.9% (molar percentage).
Present invention also offers a kind of preparation system of high polymerization degree narrow ditribution polyvinyl alcohol, including:
Polymerization reaction kettle;The polymerization reaction kettle is provided with desalted water charge door, second charging aperture and discharging opening;
The static mixer being connected with the second charging aperture of the polymerization reaction kettle;The static mixer is provided with poly-
Close monomer addition mouthful and initiator charge door;
The scrubbing tower being connected with the discharging opening of the polymerization reaction kettle;
The saponification device being connected with the discharging opening of the scrubbing tower.
According to the present invention, other additives need to be such as added, preferably be added by desalted water charge door.
When polymerization reaction kettle feeds, the charge proportion, charge order and feeding temperature to all raw materials be not special
Limitation.
The second charging aperture of the polymerization reaction kettle is connected with static mixer;The static mixer is provided with polymerization
Monomer addition mouthful and initiator charge door;Atomising device is preferably provided with the outlet nozzle of the initiator charge door, so as to
Increase the mixture homogeneity of polymerized monomer and initiator solution so that improve production efficiency, while meet the security of operation because
Element.
The structural representation of the preparation system of the high polymerization degree narrow ditribution polyvinyl alcohol that Fig. 1 is provided for the present invention, wherein 1 is
Static mixer, 2 be vinylacetate feeding pipe, 3 be initiator solution feeding pipe, 4 be that desalted water flushing line, M are
The agitator of polymerization reaction kettle.
In order to further illustrate the present invention, a kind of high polymerization degree narrow ditribution that the present invention is provided is gathered with reference to embodiments
The preparation method and preparation system of vinyl alcohol are described in detail.
Reagent used is commercially available in following examples.
Embodiment 1
Polymerization reaction kettle is decompressed to 50mmHg oxygen is removed in vacuum, then under agitation, by 200 parts of 80 DEG C of desalinations
Water, 1 part of aqueous solution and 0.5 part of carbon formed in deionized water by 0.1 part of 88% (mole) alcoholysis degree and 1700 degree of polymerization PVA
Sour hydrogen sodium, adds in polymerization reaction kettle;Then by the methanol solution of 0.1 part of 10% ABVN, the VAc with 100 parts
Simultaneously in feeding SV type static mixers, after synchronous charging is finished, reactor temperature is 50 DEG C, by the water temperature for adjusting chuck
Reactor temperature is maintained at 50 DEG C, be carried out continuously the suspension polymerisation of VAc, successive reaction 3 hours.
The polymerization liquid feeding scrubbing tower middle part that will be obtained, in bottom input steam, washes out unreacted from tower top
VAc, obtains the aqueous solution of PVAc, by after centrifugation and drying, obtaining PVAc resins.
Addition in methanol solution (the polyvinyl acetate methanol solution of configuration 20%) is added in the PVAc resins for obtaining
NaOH (being the 1% of polyvinyl acetate quality), solution dries 2h in 50 DEG C of saponification at 80 DEG C, obtains PVA, evaluates knot
Fruit is in table 1.
Embodiment 2~5
By mode same as Example 1 be polymerized VAc obtain PVAc, difference is with polymerization initiator, solvent in table 1
And its consumption, polymerization temperature and polymerization time.PVAc methanol solutions are then prepared, and saponification obtains PVA evaluation results in table 1.
Comparative example 1
Polymerization reaction kettle is decompressed to 50mmHg oxygen is removed in vacuum, then under agitation, by 200 parts of 80 DEG C of desalinations
Water, 1 part of aqueous solution formed in deionized water by 0.1 part of 88% (mole) alcoholysis degree and 1700 degree of polymerization PVA, 0.5 part of carbon
Sour hydrogen sodium, adds in reactor.Then 0.1 part of ABVN is dissolved in 100 parts of VAc, initiator will have been dissolved
VAc solution be directly added into reactor, after charging is finished, reactor temperature is 50 DEG C, is made instead by the water temperature for adjusting chuck
Answer temperature in the kettle to be maintained at 50 DEG C, be carried out continuously the suspension polymerisation of VAc, successive reaction 3 hours.
Polymerization liquid is processed according to the identical mode of embodiment 1 and obtain PVAc, prepare PVAc methanol solutions, and saponification is obtained
PVA evaluation results are in table 2.
Comparative example 2
Polymerization reaction kettle is decompressed to 50mmHg oxygen is removed in vacuum then under agitation, by 200 parts of 80 DEG C of desalinations
Water, 1 part of aqueous solution formed in deionized water by 0.1 part of 88% (mole) alcoholysis degree and 1700 degree of polymerization PVA, 0.5 part of carbon
Sour hydrogen sodium, 100 parts of VAc is added in reactor, and 0.1 part of ABVN then is directly added into reactor by hand hole,
After charging is finished, reactor temperature is 50 DEG C, reactor temperature is maintained at 50 DEG C by the water temperature for adjusting chuck, continuously
Carry out the suspension polymerisation of VAc, successive reaction 3 hours.
Polymerization liquid is processed according to the identical mode of embodiment 1 and obtain PVAc, prepare PVAc methanol solutions, and saponification is obtained
PVA evaluation results are in table 2.
Comparative example 3~5
By mode same as Example 1 be polymerized VAc obtain PVAc, difference is with polymerization initiator, solvent in table 2
And its consumption, polymerization temperature and polymerization time.PVAc methanol solutions are then prepared, and saponification obtains PVA evaluation results in table 2.
The polymerizing condition and evaluation result of the 1~embodiment of embodiment 5 of table 1
The polymerizing condition and evaluation result of the 1~comparative example of comparative example 5 of table 2
Wherein, comparative example 1 can occur a small amount of monomer autohemagglutination, and monomer delivery pipe road can produce polymer mud, influence production
Efficiency.