CN103954732B - A kind ofly measure free radical in emulsion polymerization and enter the method for continuous phase speed from latex particle desorption - Google Patents

Abstract

The invention discloses and a kind ofly measure free radical in emulsion polymerization and enter the method for continuous phase speed from latex particle desorption, initial or the monomer conversion ascent stage in the reaction of emulsion polymerization systems, add water-soluble nitroso-dithionate, by the monitoring to polymerization rate or polymer molecular weight, determine that water-soluble nitroso-dithionate consumes required time Δ t completely, calculate free radical enters continuous phase apparent speed R from latex particle desorption _dawith absolute speed R _d.The invention provides a kind of free radical enters continuous phase speed Direct Determination from latex particle desorption, operation be succinct, cost is low, test result is accurate, applied widely and highly sensitive.

Description

A kind ofly measure free radical in emulsion polymerization and enter the method for continuous phase speed from latex particle desorption

Technical field

The present invention relates to emulsion polymerization field, be specifically related to a kind ofly measure free radical in emulsion polymerization and enter the method for continuous phase speed from latex particle desorption.

Background technology

In emulsion polymerization, free radical desorption from latex particle is the key factor determining polymerization rate and latex particle form, but because the reactivity of free radical is large, the life-span is extremely short, very difficult to the seizure of its trace.At present, measure free radical from the latex particle method of desorption in reporting both at home and abroad and mainly contain the indirect method of measurement and theoretical calculation method.

The indirect method of measurement is a kind of polymerization theory model first setting up average number of free radicals and polymer molecular weight etc. in regarding polymerization speed, latex particle according to the ultimate principle of emulsion polymerization, then pushes away according to emulsion polymerization result of implementation is anti-free radical to enter continuous phase speed method from latex particle desorption.Although the method widely uses, its accuracy is directly decided by the degree of reliability about theoretical model, and still very large to the arguement of polymerization theory model at present, and the authenticity of measurement result still has problem; On the other hand, the modeling work complex in the method, needs very high theoretical tray and research skill, performance difficulty; Finally, the accuracy of the method to polymerization result of implementation relies on higher, and be seen in result discreteness in the various methods of report comparatively large, the reliability of measurement result is poor.

Theoretical calculation method is from point of theory, various mass transfer theory is utilized to measure the speed that free radical enters continuous phase from latex particle desorption, but the process entering continuous phase from latex particle desorption due to free radical is unimolecular process, and the applicability of macroscopical mass transfer theory still leaves a question open; On the other hand, in the method, desired parameters is very difficult to obtain, and limits the popularization of the method.

Summary of the invention

The object of this method is to provide and a kind ofly operates the free radical succinct, cost is low, test result is accurate, applied widely and highly sensitive enters continuous phase speed Direct Determination from latex particle desorption.

The invention discloses and a kind ofly measure free radical in emulsion polymerization and enter the method for continuous phase speed from latex particle desorption, initial or the monomer conversion ascent stage in the reaction of emulsion polymerization systems, add water-soluble nitroso-dithionate, by determining that to the monitoring of polymerization rate or polymer molecular weight water-soluble nitroso-dithionate consumes required time Δ t completely, calculate free radical enters continuous phase apparent speed R from latex particle desorption _dawith absolute speed R _d.

In described water-soluble nitroso-dithionate and emulsion polymerization systems, the mol ratio of initiating agent is 0.01 ~ 2;

Described emulsion polymerization systems forms primarily of monomer, dispersion medium, emulsifying agent and initiating agent;

Described water-soluble nitroso-dithionate has structure as follows:

Wherein, M ⁺comprise and nitroso-dithionate can be made to have water miscible kation.

Inventive principle:

In emulsion polymerization, free radical desorption can enter continuous phase (i.e. dispersion medium) from latex particle, and the free radical in continuous phase likely stops mutually, is also likely reuptaked initiation reaction by latex particle.After adding water-soluble nitroso-dithionate in continuous phase, desorption enters the free radical that produces in the free radical of continuous phase and continuous phase mutually stopping or just can be caught according to stoichiometry by water-soluble nitroso-dithionate before being reuptaked by latex particle and lose the activity of initiated polymerization, so, because the free radical of initiated polymerization is by some or all of deactivation, cause polymerization rate to reduce or polymerization stopping, polymer molecular weight increases because free radical enters latex particle rate reduction simultaneously.After the water-soluble nitroso-dithionate in continuous phase runs out of, free radical can be absorbed initiation reaction by latex particle again again, reaction rate then can return to the state added before water-soluble nitroso-dithionate, also reaches unanimity before polymer molecular weight and the water-soluble nitroso-dithionate of interpolation simultaneously.

Polymerization rate is utilized to fall or polymer molecular weight rises the duration Δ t principle identical with the time that water-soluble nitroso-dithionate consumes completely, Δ t is obtained by the change of monitoring polymerization rate or polymer molecular weight, again in conjunction with mass balance formula in continuous phase, just can measure and obtain free radical desorption and enter apparent speed in continuous phase.

By determining Δ t to the monitoring of polymerization rate, can be described in detail with reference to Fig. 1 ~ 4:

In Fig. 1 and Fig. 3, initially namely add water-soluble nitroso-dithionate in the reaction of emulsion polymerization, after polymerization starts, from reactor, take out sample test conversion ratio continuously, take the method determination polymerization rate of getting tangent line to reduce duration.

In Fig. 2 and Fig. 4, carry out the stage (conversion ratio ascent stage) add water-soluble nitroso-dithionate in the reaction of emulsion polymerization, reaction starts rear continuous taking-up sample test conversion ratio, takes the method determination polymerization rate of getting tangent line to reduce duration.

By determining Δ t to the monitoring of polymer molecular weight, can be described in detail with reference to Fig. 5 ~ 6:

In Fig. 5, initially namely add water-soluble nitroso-dithionate in the reaction of emulsion polymerization, from reactor, take out sample test polymer molecular weight continuously after polymerization starts, take the method determination polymer molecular weight ascent stage duration of getting tangent line.

In Fig. 6, carry out the stage (conversion ratio ascent stage) in the reaction of emulsion polymerization and add water-soluble nitroso-dithionate, reaction starts rear serial sampling test polymer molecular weight, takes the method determination polymer molecular weight ascent stage duration of getting tangent line.

Above-mentionedly require that every bar tangent line at least needs matching 4 linear relationship good data points when getting tangent line, and determine sampling density as standard.

Because the free radical in latex particle is except desorption, also likely react with monomer or other free radical in latex particle, so, utilize the apparent desorption rate of free radical to solve further and obtain free radical enters continuous phase absolute speed from latex particle desorption.

Described method is applicable to various emulsion polymerization systems, as classical emulsion polymerization systems, seeded emulsion polymerization system, core-shell emulsion polymerization system, emulsifier-free emulsion polymerization system, inverse emulsion polymerization system, micro-emulsion polymerization system etc.

Described computation process is as follows:

It is equal to Δ t Rule of judgment that [FS] that calculate with formula 1 ~ 3 changed to for 0 time experienced by initial value, determines parameter P as calculated _d, then determine R according to formula 4 and formula 5 respectively _daand R _d;

$\frac{d\left[R\right]}{\mathrm{dt}}=P_d\underset{i=1}{\overset{n}{\mathrm{\Σ}}}2f_i{k}_{\mathrm{di}}{\left[I\right]}_i{m}_{\mathrm{Ii}}+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}2f_i{k}_{\mathrm{di}}{\left[I\right]}_i-k_{\mathrm{tFS}}\left[R\right]\left[\mathrm{FS}\right]-k_{\mathrm{tR}}{\left[R\right]}^2$ (formula 1);

$\frac{d\left[\mathrm{FS}\right]}{\mathrm{dt}}=-k_{\mathrm{dFS}}\left[\mathrm{FS}\right]-k_{\mathrm{tFS}}\left[R\right]\left[\mathrm{FS}\right]$ (formula 2);

$\frac{d{\left[I\right]}_i}{\mathrm{dt}}=-k_{\mathrm{di}}{\left[I\right]}_i$ (formula 3);

$R_{\mathrm{da}}=P_d\underset{i=1}{\overset{n}{\mathrm{\Σ}}}2f_i{k}_{\mathrm{di}}{\left[I\right]}_i{m}_{\mathrm{Ii}}$ (formula 4);

$P_d=\frac{R_d}{R_d+2\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{k}_{\mathrm{pRi}}{\left[M\right]}_i+k_{\mathrm{tR}}\frac{2}{v_p{N}_A}}$ (formula 5);

In formula: [R] is number of free radical in dispersion medium, and n is initiator type number, f _ithe efficiency that i decomposition of initiator forms free radical, k _dii decomposition of initiator rate constant, [I] _ii initiator concentration in dispersion medium, P _dundetermined parameter, m _iibe i initiating agent at latex particle and partition factor continuously, k _tFSthe rate constant of water-soluble nitroso-dithionate and free radical reaction, k _tRbe the rate constant that free radical reacts to each other, [FS] is water-soluble nitroso-dithionate concentration in dispersion medium, k _dFSwater-soluble nitroso-dithionate selfdecomposition rate constant, R _dabe the apparent speed of free radical desorption from latex particle, Rd is the absolute speed of free radical desorption from latex particle, k _pRithe rate constant of free radical and i monomer reaction, [M] _ithe concentration of i monomer in latex particle, v _pfor latex particle average-size, N _ait is Avogadro constant.

The concrete steps of the described monitoring to polymerization rate or polymer molecular weight are: from reactor, take out sample determination polymerisation conversion or polymer molecular weight continuously after reaction starts, and the relation of itself and time is depicted as curve.In the front and back cluster sampling that polymerization rate or polymerizable molecular amount change, ensure when being changed phases-time length by tangent method determination polymerization rate or polymerizable molecular amount, get in tangent line process and have at least 4 linear relationships to put preferably for matching.

The assay method of polymerization rate comprises can determine that in polymerization system, polymkeric substance or monomer account for the method for system total amount, assaying reaction object amasss time dependent method and directly can determine the method for polymerization rate, as: by polymer content in gravimetric determination samples of latex thus measure polymerization rate, by content of monomer in gas chromatography determination emulsion thus measure polymerization rate, utilize dilatometer measurement reactant volumetric contraction thus measure polymerization rate and utilization thermal reactor etc. and directly measure polymerization rate etc., but be not limited to the method for said determination polymerization rate.

The assay method of polymer molecular weight comprises the method can determining polymkeric substance relative molecular weight or absolute molecular weight, as: gel permeation chromatography, viscosimetry, light scattering method, mass spectroscopy etc., but be not limited to the method for said determination polymer molecular weight.

Described emulsion polymerization systems comprises the raw material of following percentage by weight:

Monomer 0.998 ~ 74%, dispersion medium 24 ~ 99%, emulsifying agent 0.001 ~ 20%, initiating agent 0.001 ~ 10%, reagent and additive in polymerization 0 ~ 30%;

Described monomer is one or more, and having at least a kind of in monomer is oil-soluble monomer;

Described dispersion medium is the mixed liquor of miscible with the water at the reaction temperatures organic solvent of water or at least one and water, and described temperature of reaction is 25 ~ 90 DEG C;

Described emulsifying agent is surfactant, average-size is 1 ~ 1000nm inorganic nano-particle or organic dispersing agent;

Described initiating agent is oil-soluble initiator or part oil-soluble initiator.

Oil-soluble monomer described in the present invention refers to: when 25 DEG C, and the solubleness of monomer in water is less than or equal to 10%.

Described part oil-soluble initiator refers to: initiating agent has well water-soluble, but when there being oil phase to exist, this initiating agent also can be partially soluble in oil phase.

Described monomer can be butyl acrylate, methyl methacrylate, octadecyl methacrylate, styrene, butadiene, vinyl cyanide etc., but is not limited to this.

The mixed liquor of the organic solvent that described at least one is miscible with water at the reaction temperatures and water can be ethanol-water solution, dimethyl sulfoxide (DMSO)-aqueous solution, N, N '-dimethyl formamide-acetic acid-aqueous solution etc., but is not limited to this.

Described emulsifying agent can be lauryl sodium sulfate, cetyl trimethyl ammonium bromide, dodecyldimethylammonium hydroxide inner salt, Tween 80, nano silicon, tricalcium phosphate powder, polyglycol, gelatin etc., but is not limited to this.

Described initiating agent can be azo two isobutyric acid hydroxy butyl ester, benzoyl peroxide, ABVN, N, at least one in N '-dimethyl aniline-benzoyl peroxide system, but is not limited to this.

Described reagent and additive in polymerization comprises alkane, alkene, alkynes, at least one in unitary or polynary alcohol or acid that pH buffering agent and the total number of carbon atoms are more than or equal to 4, as: isooctadecane, n-hexadecene, 8-hexadecyne, isoamylol, n-butyric acie, stearic acid etc., but be not limited thereto.

The preparation of described emulsion polymerization systems and polymerization process are:

Monomer, dispersion medium, emulsifying agent, initiating agent and reagent and additive in polymerization are mixed, after applying to shear formation emulsion, drop in reactor, heating up under blanket gas atmosphere starts polyreaction.

When described emulsion polymer is seeded emulsion polymerization system, need first to prepare seed latex, and then carry out emulsion polymerization by the emulsion polymerization process of above-mentioned routine.

Described cut mode comprises single or uses mechanical stirring device, rocking equipment, ultrasonic disperse device, high pressure homogenization device etc. can to disperse reactant the device that reactant applies shearing force simultaneously, but is not limited to device and the form of the above-mentioned several applying shearing forces enumerated.

Described protection gas bag is drawn together and is not disturbed polymerization and gas that can not react with reactant in emulsion and composition thereof, as: one or more in nitrogen, hydrogen, methane, acetylene, inert gas, but be not limited to above-mentioned gas.

As preferably, when described monomer is butyl acrylate, described initiating agent is peroxide initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain cationic surfactant.

Further preferably, when described monomer is butyl acrylate,

Described initiating agent is benzoyl peroxide;

Described emulsifying agent is cetyl trimethyl ammonium bromide;

Described dispersion medium is methyl alcohol-formamide-aqueous solution.

As preferably, when described monomer is styrene or styrene derivative, initiating agent is part oil-soluble azo initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain anionic surfactant and be on average of a size of the potpourri of inorganic nano-particle of 1 ~ 1000nm.

Described styrene derivative is that α position or phenyl ring have substituent styrene monomer, as α-methyl styrene, 4-chlorostyrene etc.;

Further preferably, when described monomer is styrene or α-methyl styrene;

Described initiating agent is azo two isobutyric acid hydroxy butyl ester and azo two methyl isobutyrate;

Described emulsifying agent is the potpourri of lauryl sodium sulfate and nano silicon.

As preferably, described monomer is methacrylate octadecyl ester, and described initiating agent is oil-soluble azo initiator, and emulsifying agent is Tweens surfactant, or is organic dispersing agent and the potpourri of inorganic nano-particle being on average of a size of 1 ~ 1000nm.

Further preferably, when described monomer is methacrylate octadecyl ester,

Described initiating agent is azoisobutyronitrile;

Described emulsifying agent is Tween 80, or is the potpourri of nanometer tricalcium phosphate powder, polyglycol and gelatin; The tricalcium phosphate powder of described nanometer tricalcium phosphate powder to be average-size be 700 ~ 1000nm;

Described dispersion medium is water or ethanol water.

As preferably, described monomer is the potpourri of styrene and γ-methacryloxypropyl trimethoxy silane, initiating agent is oil-soluble azo initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain anionic surfactant and be on average of a size of the potpourri of inorganic nano-particle of 1 ~ 1000nm.

Further preferably, when described monomer is the potpourri of styrene and γ-methacryloxypropyl trimethoxy silane,

Described initiating agent is azoisobutyronitrile;

Described emulsifying agent is the potpourri of lauryl sodium sulfate, neopelex and nano tricalcium phosphate.

As preferably, described monomer is at least two kinds in styrene, vinyl cyanide, methyl methacrylate, initiating agent is oil insoluble oxidation reduction initiating system or oil-soluble azo initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain zwitterionic surfactant.

Further preferably, when described monomer is styrene and methyl methacrylate, or be styrene, methyl methacrylate and vinyl cyanide,

Described initiating agent is azoisobutyronitrile;

Described emulsifying agent is dodecyldimethylammonium hydroxide inner salt.

Compared with prior art, tool of the present invention has the following advantages:

The present invention adopts water-soluble nitroso-dithionate to be free radical scavenger, utilize basic chemical principle and material balance relationship, the speed that free radical enters continuous phase from latex particle desorption is directly measured, the important parameters such as apparent desorption rate and absolute desorption rate can be obtained simultaneously, have that instrument is simple, simple testing process is quick, method is applied widely and the advantage such as test result is accurate.

Accompanying drawing explanation

Fig. 1 is that the reaction of emulsion polymerization initially adds water-soluble nitroso-dithionate, when polymerization rate is 0, and the variation relation curve of monomer conversion and time;

Fig. 2 is that the reaction of emulsion polymerization is carried out the stage and added water-soluble nitroso-dithionate, when polymerization rate is 0, and the variation relation curve of monomer conversion and time;

Fig. 3 is that the reaction of emulsion polymerization initially adds water-soluble nitroso-dithionate, when polymerization rate reduces, and the variation relation curve of monomer conversion and time;

Fig. 4 is that the reaction of emulsion polymerization is carried out the stage and added water-soluble nitroso-dithionate, when polymerization rate reduces, and the variation relation curve of monomer conversion and time;

Fig. 5 is that the reaction of emulsion polymerization initially adds water-soluble nitroso-dithionate, the variation relation curve of polymer molecular weight and time;

Fig. 6 is that the reaction of emulsion polymerization is carried out the stage and added water-soluble nitroso-dithionate, the variation relation curve of polymer molecular weight and time.

Embodiment

Below by embodiment, the present invention is set forth further, but do not limit the present invention.

Embodiment 1

850g water, 30g methyl alcohol, 20g formamide, 96g butyl acrylate, 1g cetyl trimethyl ammonium bromide, 1g n-hexadecene, 1g Potassium Hydrogen Phthalate and 1g benzoyl peroxide are mixed; emulsion is formed through mechanical raking; by this emulsion input amount thermal reactor, heat up after passing into nitrogen eliminating oxygen and start reaction.Temperature of reaction is 90 DEG C, and polymerization starts to monitor polymerization rate afterwards.Reaction adds nitroso-two potassium sulfate solution of 1mL1.1wt% in system when proceeding to 20 minutes.Measure the polymerization rate decline stage continue time be 160s, according to formula 1 ~ 3 optimize obtain P _d=0.87, and then calculate according to formula 4 the apparent speed R that primary group of free radicals desorption from latex particle enters continuous phase _da=7.03 × 10 ^-6mol/ (Ls), calculates according to formula 5 the absolute speed R that primary group of free radicals desorption from latex particle enters continuous phase _d=3.4 × 10 ⁶s ^-1.F=0.67, k in test _d=1.44 × 10 ^-4s ^-1, k _dFS=9.25 × 10 ^-3s ^-1, m _i=250, k _tR=k _tFS=2 × 10 ⁹mol/ (Ls), k _pR=8.82 × 10 ³mol/ (Ls), [M]=6.7mol/L, v _p=1.42 × 10 ^-20l.

Embodiment 2

Be the silicon dioxide of 1nm, 230g n-amyl alcohol, 50g suberic acid, 9g n-octadecane, the positive hexadecanol of 8g, 1g8-hexadecyne, 2g borax, 50g azo two isobutyric acid hydroxy butyl ester (initiating agent 1) and 50g azo two methyl isobutyrate (initiating agent 2) mixing by 350g water, 50g α-methyl styrene, 199g lauryl sodium sulfate, 1g average-size, emulsion is formed through mechanical raking, this emulsion is dropped into 2000mL glass jacket reactor, heating up after passing into nitrogen eliminating oxygen starts reaction.Temperature of reaction is 25 DEG C, and polymerization starts rear gravimetric method and viscosimetry is monitored polymerization rate and polymer molecular weight respectively.Reaction adds nitroso-two aqueous sodium persulfate solution of 50mL30wt% in system when proceeding to 10 minutes.Record time that the polymerization rate decline stage continues and the time that polymer molecule ascent stage continues is 8700s, obtain P according to formula 1 ~ 3 optimization _d=0.70, and then calculate according to formula 4 the apparent speed R that primary group of free radicals desorption from latex particle enters continuous phase _da=1.48 × 10 ^-5mol/ (Ls).F in test ₁=f ₂=0.7, k _d1=4.1 × 10 ^-6s ^-1, k _d2=1.8 × 10 ^-6s ^-1, k _dFS=5.25 × 10 ^-6s ^-1, m _i1=2.8, m _i2=595, k _tR=k _tFS=2 × 10 ⁹mol/ (Ls), k _pR=88.2mol/ (Ls), [M]=7mol/L, v _p=3.52 × 10 ^-21l.

Embodiment 3

980g water, 10g ethanol, 9.98g octadecyl methacrylate, 0.01g Tween 80 and 0.01g azoisobutyronitrile are mixed, form emulsion through ultrasonic cell disruptor dispersion churned mechanically simultaneously, this emulsion is dropped into 2000mL glass jacket reactor, heating up after passing into nitrogen-argon-mixed eliminating oxygen starts reaction.Temperature of reaction is 60 DEG C, and polymerization starts rear vapor-phase chromatography and monitors polymerization rate.Reaction adds the nitroso-two sulfate of ammoniac aqueous solution of 1mL0.1wt% in system when just starting.The duration recording the polymerization rate decline stage is 3120s, obtains P according to formula 1 ~ 3 optimization _d=0.91, and then calculate according to formula 4 the apparent speed R that primary group of free radicals desorption from latex particle enters continuous phase _da=7.03 × 10 ^-9mol/ (Ls), calculates according to formula 5 the absolute speed R that primary group of free radicals desorption from latex particle enters continuous phase _d=1.75 × 10 ⁶s ^-1.F=0.7, k in test _d=1.27 × 10 ^-5s ^-1, k _dFS=1.57 × 10 ^-4s ^-1, m _i=110, k _tR=k _tFS=2 × 10 ⁹mol/ (Ls), k _pR=8.54 × 10 ³mol/ (Ls), [M]=8mol/L, v _p=8.62 × 10 ^-20l.

Embodiment 4

Be the tricalcium phosphate of 1000nm, 3g lauryl sodium sulfate, 3g dodecyl benzene sulphur sodium and the mixing of 1g azoisobutyronitrile by 450g water, 440g styrene (monomer 1), 100g γ-methacryloxypropyl trimethoxy silane (monomer 2), 3g average-size, emulsion is formed through ultrasonic cell disruptor dispersion, this emulsion is dropped into 2000mL glass jacket reactor, heating up after passing into hydrogen eliminating oxygen starts reaction.Temperature of reaction is 60 DEG C, and polymerization starts rear viscosimetry and monitors polymer molecular weight.Nitroso-two potassium sulfate solution adding 10mL1wt% for 30 minutes in backward system is carried out in reaction.The duration recording polymer molecular weight ascent stage is 4280s, obtains P according to formula 1 ~ 3 optimization _d=0.57, and then calculate according to formula 4 the apparent speed R that primary group of free radicals desorption from latex particle enters continuous phase _da=1.12 × 10 ^-7mol/ (Ls), calculates according to formula 5 the absolute speed R that primary group of free radicals desorption from latex particle enters continuous phase _d=6.01 × 10 ⁴s ^-1.F=0.7, k in test _d=1.27 × 10 ^-5s ^-1, k _dFS=1.57 × 10 ^-4s ^-1, m _i=120, ktR=ktFS=2 × 10 ⁹mol/ (Ls), k _pR1=4.79 × 10 ³mol/ (Ls), k _pR2=12.69 × 10 ³mol/ (Ls), [M] ₁=4.56mol/L, [M] ₂=1.04mol/L, v _p=1.47 × 10 ^-17l.

Embodiment 5

Be tricalcium phosphate powder and the mixing of 1g azoisobutyronitrile of 700nm by 240g water, 740g octadecyl methacrylate, 17g cetomacrogol 1000,1g gelatin, 1g average-size, emulsion is formed through ultrasonic cell disruptor dispersion, this emulsion is dropped into 2000mL glass jacket reactor, heating up after passing into nitrogen eliminating oxygen starts reaction.Temperature of reaction is 60 DEG C, and polymerization starts rear gel permeation chromatography and monitors polymer molecular weight.Reaction adds nitroso-two potassium sulfate solution of 10mL0.4wt% in system when just starting.The time recording polymer molecular weight ascent stage lasting is 6550s, obtains P according to formula 1 ~ 3 optimization _d=0.069, and then calculate according to formula 4 the apparent speed R that primary group of free radicals desorption from latex particle enters continuous phase _da=3.11 × 10 ^-8mol/ (Ls), calculates according to formula 5 the absolute speed R that primary group of free radicals desorption from latex particle enters continuous phase _d=5.10 × 10 ³mol/ (Ls).F=0.7, k in test _d=1.27 × 10 ^-5s ^-1, k _dFS=1.57 × 10 ^-4s ^-1, m _i=110, k _tR=k _tFS=2 × 10 ⁹mol/ (Ls), k _pR=8.54 × 10 ³mol/ (Ls), [M]=8mol/L, v _p=6.55 × 10 ^-17l.

Embodiment 6

70g water, 20g styrene, 9.5g methyl methacrylate, 0.3g dodecyldimethylammonium hydroxide inner salt and 0.2g azoisobutyronitrile are mixed, emulsion is formed through mechanical raking, this emulsion is dropped into 200mL glass jacket reactor, heating up after passing into methane eliminating oxygen starts reaction.Temperature of reaction is 80 DEG C, reacts after 24 hours and stops reaction.Get 50g above-mentioned emulsion, add 30g water, 19.85g styrene and 0.1g benzoyl peroxide and 0.05gN, N '-dimethyl aniline, seed emulsion is formed after 24 hours through mechanical raking, this seed emulsion is dropped into 100mL with in the dilatometer of magnetic stirring apparatus, heating up after passing into hydrogen eliminating oxygen starts reaction.Temperature of reaction is 30 DEG C, monitors in polymerization process by volumetric contraction method to polymerization rate.Nitroso-two potassium sulfate solution adding 1mL5% for 1 hour in backward system is carried out in seeded emulsion polymerization reaction.The duration recording the polymerization rate decline stage is 3880s, obtains P according to formula 1 ~ 3 optimization _d=0.54, and then calculate according to formula 4 the apparent speed R that primary group of free radicals desorption from latex particle enters continuous phase _da=1.27 × 10 ^-6mol/ (Ls), calculates according to formula 5 the absolute speed R that primary group of free radicals desorption from latex particle enters continuous phase _d=6.91 × 10 ⁴mol/ (Ls).F=0.6, k in test _d=3.27 × 10 ^-4s ^-1, k _dFS=5.25 × 10 ^-6s ^-1, m _i=250, k _tR=k _tFS=2 × 10 ⁹mol/ (Ls), k _pR=8.54 × 10 ³mol/ (Ls), [M]=3.4mol/L, v _p=5.24 × 10 ^-19l.

Embodiment 7

80g water, 10g styrene, 9.5g methyl methacrylate, 0.38g dodecyldimethylammonium hydroxide inner salt and 0.12g azoisobutyronitrile are mixed, emulsion is formed through mechanical raking, this emulsion is dropped into 200mL glass jacket reactor, heating up after passing into methane eliminating oxygen starts reaction.Temperature of reaction is 60 DEG C, reacts after 2 hours and stops reaction.Get 90g above-mentioned emulsion, add 10g vinyl cyanide, form seed emulsion through mechanical raking after 24 hours, this seed emulsion dropped in 200mL glass jacket reactor, heating up after passing into hydrogen eliminating oxygen starts reaction.Temperature of reaction is 70 DEG C, monitors in polymerization process by weight method to polymerization rate.Nitroso-two potassium sulfate solution adding 3mL13% for 0.2 hour in backward system is carried out in seeded emulsion polymerization reaction.The duration recording the polymerization rate decline stage is 8780s, obtains P according to formula 1 ~ 3 optimization _d=0.41, and then calculate according to formula 4 the apparent speed R that primary group of free radicals desorption from latex particle enters continuous phase _da=6.16 × 10 ^-8mol/ (Ls), calculates according to formula 5 the absolute speed R that primary group of free radicals desorption from latex particle enters continuous phase _d=3.41 × 10 ⁴mol/ (Ls).F=0.7, k in test _d=1.27 × 10 ^-5s ^-1, k _dFS=1.57 × 10 ^-4s ^-1, m _i=120, k _tR=k _tFS=2 × 10 ⁹mol/ (Ls), k _pR=8.54 × 10 ³mol/ (Ls), [M]=2.4mol/L, v _p=5.65 × 10 ^-17l.

Claims (8)

1. one kind measures free radical in emulsion polymerization and enters the method for continuous phase speed from latex particle desorption, it is characterized in that, initial or the monomer conversion ascent stage in the reaction of emulsion polymerization systems, add water-soluble nitroso-dithionate, by the monitoring to polymerization rate or polymer molecular weight, determine that water-soluble nitroso-dithionate consumes required time Δ t completely, calculate free radical enters continuous phase apparent speed R from latex particle desorption _dawith absolute speed R _d;

In described water-soluble nitroso-dithionate and emulsion polymerization systems, the mol ratio of initiating agent is 0.01 ~ 2;

Described emulsion polymerization systems forms primarily of monomer, dispersion medium, emulsifying agent and initiating agent;

Described water-soluble nitroso-dithionate has structure as follows:

Wherein: M ⁺to make nitroso-dithionate have water miscible kation.

2. method according to claim 1, is characterized in that, [FS] that calculate with formula 1 ~ 3 changed to for 0 time experienced equal with Δ t by initial value is Rule of judgment, determines parameter P through optimizing calculating _d, then determine R according to formula 4 and formula 5 respectively _daand R _d;

(formula 1);

(formula 2);

(formula 3);

(formula 4);

(formula 5);

In formula: [R] is number of free radical in dispersion medium, and n is initiator type number, f _ithe efficiency that i decomposition of initiator forms free radical, k _dii decomposition of initiator rate constant, [I] _ii initiator concentration in dispersion medium, P _dundetermined parameter, m _iibe i initiating agent at latex particle and partition factor continuously, k _tFSthe rate constant of water-soluble nitroso-dithionate and free radical reaction, k _tRbe the rate constant that free radical reacts to each other, [FS] is water-soluble nitroso-dithionate concentration in dispersion medium, k _dFSwater-soluble nitroso-dithionate selfdecomposition rate constant, R _dathe apparent speed of free radical desorption from latex particle, R _dthe absolute speed of free radical desorption from latex particle, k _pRithe rate constant of free radical and i monomer reaction, [M] _ithe concentration of i monomer in latex particle, v _pfor latex particle average-size, N _ait is Avogadro constant.

3. method according to claim 1, is characterized in that, described emulsion polymerization systems comprises the raw material of following percentage by weight:

Monomer 0.998 ~ 74%, dispersion medium 24 ~ 99%, emulsifying agent 0.001 ~ 20%, initiating agent 0.001 ~ 10%, reagent and additive in polymerization 0 ~ 30%;

Described monomer is one or more, and having at least a kind of in monomer is oil-soluble monomer;

Described dispersion medium is the mixed liquor of miscible with the water at the reaction temperatures organic solvent of water or at least one and water, and described temperature of reaction is 25 ~ 90 DEG C;

Described emulsifying agent is surfactant and/or average-size is the inorganic nano-particle of 1 ~ 1000nm;

Described initiating agent is oil-soluble initiator or part oil-soluble initiator.

4. method according to claim 3, is characterized in that, described monomer is butyl acrylate, and described initiating agent is peroxide initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain cationic surfactant.

5. method according to claim 3, it is characterized in that, described monomer is styrene or styrene derivative, initiating agent is part oil-soluble azo initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain anionic surfactant and be on average of a size of the potpourri of inorganic nano-particle of 1 ~ 1000nm.

6. method according to claim 3, it is characterized in that, described monomer is octadecyl methacrylate, described initiating agent is oil-soluble azo initiator, emulsifying agent is the potpourri of organic dispersing agent and the inorganic nano-particle being on average of a size of 1 ~ 1000nm, or Tweens surfactant.

7. method according to claim 3, it is characterized in that, described monomer is the potpourri of styrene and γ-methacryloxypropyl trimethoxy silane, initiating agent is oil-soluble azo initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain anionic surfactant and be on average of a size of the potpourri of inorganic nano-particle of 1 ~ 1000nm.

8. method according to claim 3, it is characterized in that, described monomer is at least two kinds in styrene, vinyl cyanide, methyl methacrylate, initiating agent is oil insoluble oxidation reduction initiating system or oil-soluble azo initiator, emulsifying agent to be carbon number be 12 ~ 24 Long carbon chain zwitterionic surfactant.