CN103721627A

CN103721627A - Thermosensitive miktoarm star high molecular emulsifier and preparation method thereof

Info

Publication number: CN103721627A
Application number: CN201310685017.0A
Authority: CN
Inventors: 安泽胜; 徐媛媛; 陈起静; 孙晓岚
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2013-12-16
Filing date: 2013-12-16
Publication date: 2014-04-16

Abstract

The invention relates to a thermosensitive miktoarm star high molecular emulsifier and a preparation method thereof. According to the high molecular emulsifier, two different kinds of monomers respectively form high molecular linear arms with the degree of polymerization of 65-150 in a way of reversible addition-fragmentation chain transfer polymerization (RAFT), wherein one kind of the high molecular linear arms has heat sensitivity while the other kind of the high molecular linear arms is hydrosoluble, and then the two kinds of high molecular linear arms are used as regulating agents to form a nuclear crosslinked star high macromolecule via a heterogeneous polymerization crosslinking agent. The preparation method of the nuclear crosslinked star high macromolecule is simple and easy to implement, mainly performs the synthesis is in water, does not require noxious organic reagents, belongs to environmental-friendly preparation processes, and is easy to realize large-scale industrial production; the nuclear crosslinked star high molecular emulsifier belongs to a novel, efficient, noxious and intelligent emulsifier with low irritability, formed emulsion can be directly used as an end product, and more industrial applications and higher utility value can be realized in the future.

Description

Assorted arm star macromolecule emulsifier of thermal sensitivity and preparation method thereof

Technical field

The present invention relates to a kind of star-like macromolecule emulsifier and preparation method thereof.Assorted arm star macromolecule emulsifier of a kind of thermal sensitivity and preparation method thereof particularly.

Background technology

Emulsifying agent (emulsifier) is to make two kinds of immiscible liquid form the material of stable emulsion.Emulsifying agent is to have amphiphatic surfactant in general, and hydrophilic radical is generally the group of polarity, as carboxylic acid, sulfonic acid, sulfuric acid, amino or amido and salt thereof, and also hydroxyl, amide groups, ethyoxyl etc.; And hydrophobic group is generally longer hydrocarbon chain.In addition, micron or the solid particle of Nano grade also can be used as emulsifying agent, and as clay particle etc., this type of emulsifying agent is called Pickering emulsifying agent, and they must possess the suitable wetability of two-phase, and the emulsion of formation has higher stability conventionally.

Star-like macromolecule, referring to that the above linear polymer chain of three or three (image be called " macromolecule arm ") is connected to " starlike " polymer forming on a common tie point by its high molecular one end, is that branching is opened up in benefit structure one of the simplest structure.The tie point having in the star-like macromolecule of less macromolecule arm number is generally an organic compound, and the high molecular tie point of core couple stars type with crosslinked larger macromolecule arm number is undersized, a highly cross-linked polymer core.The size of its center must be much smaller than the size of macromolecule arm, and its macromolecule arm can be unfolded and come well in good solvent, makes star-like macromolecule have good dissolubility.Star-like high molecular unique texture feature makes them at aspects such as drug delivery, catalysis, coating and rheology modifiers, have good application.And it is also rarely seen in report used as emulsifying agent aspect.

Summary of the invention

One of object of the present invention is to provide the assorted arm star macromolecule emulsifier of a kind of thermal sensitivity.

Two of object of the present invention is to provide the preparation method of the assorted arm star macromolecule emulsifier of this thermal sensitivity.

The present invention adopts reversible addition-fracture chain transfer polymerization (RAFT) method, by two steps, prepares the crosslinked star-like macromolecule of core, and the first step is the preparation of two kinds of macromolecule arms; Second step is the crosslinked star-like high molecular preparation of core.Water soluble polymer arm be by RAFT method to some, as n,N-DMAA (DMA), methoxypolyethylene glycol methacrylate (PPEGMA), 2-(dimethylamino) EMA (DMAEMA) etc. come polymerization to form polyamino polymer arm; Thermoresponsive arm is obtained by RAFT method equally by NIPA (NIPAM).After forming two kinds of macromolecule arms, then by the heteropolymerization in water, be cross-linked to form the crosslinked star-like macromolecule of core, in this step, available crosslinking agent is n, n'-methylene-bisacrylamide, glycol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediyl ester, three (ethylene glycol) diacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethylacrylate, 1,4-butanediol dimethylacrylate, HDDMA, three (ethylene glycol) dimethylacrylate etc.Below to take N,N-DMAA (DMA) and NIPA (NIPAM) to prepare the synthesis mechanism of the assorted arm star macromolecule emulsifier of thermal sensitivity as monomer:

Figure 2013106850170100002DEST_PATH_IMAGE001

Reaction 1

Reaction 2

Figure 2013106850170100002DEST_PATH_IMAGE003

Reaction 3

According to above reaction mechanism, this experiment adopts following reaction scheme:

The star-like macromolecule emulsifier of a kind of thermal sensitivity, it is characterized in that this macromolecule emulsifier is by heteropolymerization crosslinking agent, to form the crosslinked star-like macromolecule of core by thermoresponsive linear arms and water soluble polymer linear arms, the mol ratio of Linear Polymer arm and crosslinking agent is 3:30, and wherein the mol ratio of water soluble polymer linear arms and thermoresponsive linear arms is 1:0.75 ~ 1.25; The degree of polymerization of two kinds of Linear Polymer arms is 60～150.

The star-like macromolecule emulsifier of above-mentioned thermal sensitivity, is characterized in that described formation thermoresponsive arm monomer used is: NIPA NIPAM.

The star-like macromolecule emulsifier of above-mentioned thermal sensitivity, is characterized in that the monomer of described formation water soluble polymer linear arms is: N,N-DMAA DMA, methoxypolyethylene glycol methacrylate PPEGMA or methoxypolyethylene glycol acrylate PEGA.

Above-mentioned crosslinking agent is: n, n'-methylene-bisacrylamide, glycol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediyl ester, three (ethylene glycol) diacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethylacrylate, 1,4-butanediol dimethylacrylate, HDDMA or three (ethylene glycol) dimethylacrylate.

A method of preparing the above-mentioned star-like macromolecule emulsifier of thermal sensitivity, is characterized in that the concrete steps of the method are:

A. by chain-transferring agent (methyl 2-(((ethylmercapto group) thiocarbonyl) sulfenyl) ethyl propionate), thermosensitive polymer monomer, oil-soluble initator azodiisobutyronitrile AIBN according to 1:(80～200): the mol ratio of (0.02～0.04) joins in solvent, under inert atmosphere, 70 ℃ of reactions 3～4 hours, after polymerization finishes, polymer is purified, obtain thermoresponsive arm;

B. by chain-transferring agent (methyl 2-(((ethylmercapto group) thiocarbonyl) sulfenyl) ethyl propionate), thermosensitive polymer monomer, oil-soluble initiator A IBN(azodiisobutyronitrile) according to 1:(80～200): the mol ratio of (0.02～0.04) joins in solvent, under inert atmosphere, 70 ℃ of reactions 3～4 hours, after polymerization finishes, polymer is purified, obtain water soluble polymer arm;

C. by two kinds of star-like Linear Polymer arms preparing in steps A and step B, crosslinking agent, water miscible initator V50 according to 1:(3～30): the molar ratio of (0.01～1.0) is added to the water, and to control solid content be 1～50 wt%; Under inert atmosphere, at 70 ℃, heat 4～5 hours, can obtain preparing the crosslinked star-like macromolecule of core, centrifugal purification, can obtain the star-like macromolecule emulsifier of pure thermal sensitivity.

This experimental procedure is simple, easy to operate, and those skilled in the art can well realize.

The present invention considers that core is cross-linked star-like high molecular unique texture feature, be the flexibility of its macromolecule arm and the multiplicity of conformation, with and nano level size (10-50 nanometer), think the interface that the crosslinked star-like macromolecule of core can be stablized oil-water as emulsifying agent.On the interface of oil-water, the crosslinked star-like high molecular flexible arm of core can make it adopt preferred conformation and two kinds of liquid effects, and the size of its Nano grade can make it have higher energy of adsorption, strengthens its existence on interface.At present, the crosslinked assorted high molecular preparation of arm star of nearly all core, exists that preparation efficiency is low, sample dispersion degree is high and the shortcoming such as environmental pollution.We have developed and have a kind ofly efficiently prepared that content is higher, high-quality assorted arm star macromolecule take heteropolymerization method that water is dispersion liquid, not only improved preparation efficiency, reduced cost, also alleviated environmental pollution, and use RAFT method, by first synthesizing the assorted arm star macromolecule of method preparation of arm, have not been reported.

This emulsifying agent, because having thermal sensitivity, forms gel emulsion in the time of can allowing oil phase volume fraction be not less than 30%, and can be by regulating temperature to realize the reversible transition between flowable state emulsion and gel state emulsion.

The crosslinked assorted arm star macromolecule of thermal sensitivity core that experiment showed, us can (can lowly reach 0.01 wt%) and form stable emulsion under very low emulsifier concentration.When the crosslinked star-like high molecular concentration of core is at 0.3 wt% and when above, the oil phase volume fraction of emulsification can, up to more than 80%, be the very efficient emulsifying agent of a class.When oil phase volume fraction is higher than 75% time, emulsion is had mobility hardly, becomes the state of gel, image be called HIPE.HIPE can be used for preparing porous material, and its application relates to building, the energy, medical treatment, Industrial Catalysis, environment various aspects.Wherein, the crosslinked star-like macromolecule of core in the present invention has response to temperature, and when temperature is higher than 40 ℃, emulsifying agent self just can become gel in very low concentration (can lowly reach 0.5 wt%), when reducing temperature, becomes rapidly again flowable state; When carrying out emulsification, temperature is higher than 40 ℃, and when oil phase volume fraction is lower (as 30%, 50%), emulsion just can become gel, and when temperature reduces, what become rapidly again can flow; This character has very important application at aspects such as oil, chemical industry, biologies.

Accompanying drawing explanation

fig. 1 is the assorted high molecular structural representation of arm star of thermal sensitivity.

Fig. 2 is assorted nuclear-magnetism figure corresponding to arm star macromolecule of thermal sensitivity.

Fig. 3 is the high molecular GPC figure of the assorted arm star of thermal sensitivity.

Fig. 4 is that concentration is the temperature variant DLS figure of the assorted arm star macromolecule of PDMA-PNIPAM0.698 thermal sensitivity of 0.5 wt%.

Fig. 5 is that concentration is the temperature variant DLS figure of the assorted arm star macromolecule of PDMA-PNIPAM0.743 thermal sensitivity of 0.5 wt%

Fig. 6 is that concentration is the temperature variant DLS figure of the assorted arm star macromolecule of PDMA-PNIPAM0.634 thermal sensitivity of 0.5 wt%

Fig. 7 is that concentration thermal sensitivity star amphiphilic macromolecule is respectively in the state diagram of 20 ℃ and 40 ℃, (a) for concentration is that the PDMA-PNIPAM0.698 of 3.0 wt% is respectively in the state diagram of 20 ℃ and 40 ℃, (b) for concentration is that the PDMA-PNIPAM0.743 of 2.0 wt% is respectively in the state diagram of 20 ℃ and 40 ℃, (c) for concentration is that the PDMA-PNIPAM0.634 of 2.5 wt% is respectively in the state diagram of 20 ℃ and 40 ℃.

Fig. 8 is 0.50 wt% for working as the assorted arm star polymer concentration of thermal sensitivity, with oil phase dodecane volume fraction, increase the emulsion photo of its formation, (a) PDMA-PNIPAM0.698, (b) PDMA-PNIPAM0.743, (c) PDMA-PNIPAM0.634

Fig. 9 is 80% for working as oil phase volume fraction, the emulsion photo of the assorted arm star macromolecule of thermal sensitivity when variable concentrations, and wherein oil phase is dodecane,

(a) PDMA-PNIPAM0.698 concentration is respectively 0.50 wt%, 0.30 wt%, 0.20 wt%, 0.10 wt%, emulsion photo during 0.05 wt%, (b) PDMA-PNIPAM0.743 concentration is respectively 0.50 wt%, 0.30 wt%, 0.20 wt%, emulsion photo during 0.10 wt%, (c) PDMA-PNIPAM0.634 concentration is respectively 0.50 wt%, 0.30 wt%, emulsion photo during 0.10 wt%.

When Figure 10 is low oil phase volume fraction, the assorted arm star macromolecule of thermal sensitivity is the emulsion photo at 40 ℃ as emulsifying agent, (a) when PDMA-PNIPAM0.698 concentration is 0.50 wt%, oil phase volume fraction is respectively 30 %, the emulsion photo of 50 %, (b) when PDMA-PNIPAM0.743 concentration is 0.50 wt%, oil phase volume fraction is respectively the emulsion photo of 50 %, (c), when PDMA-PNIPAM0.634 concentration is 0.50 wt%, oil phase volume fraction is respectively the emulsion photo of 50 %.

Figure 11 is for when oil phase volume fraction being a 80%(left side), 50%(is right) assorted arm star macromolecule (a) PDMA-PNIPAM0.698 of thermal sensitivity, (b) PDMA-PNIPAM0.743, (c) the burnt microphoto of copolymerization during PDMA-PNIPAM0.634, wherein oil phase dodecane is dyeed by Nile red, and scale is 50 μ m.

Picture (A) the CC S (PDMA15) of the emulsion that the star-like macromolecule toluene of Figure 12 molten (0.5%w/v) volume ratio increases gradually, (B) CCS (PDMA12-PMEA5), (C) CCS (PDMA10-PMEA8), (D) CCS (PDMA7-PMEA10), (E) CCS (PMEA24). left figure is the picture of emulsification after 7 days, and right figure is the firm emulsification picture of a day.

The specific embodiment

Synthetic Linear Polymer arm

embodiment mono-:

1. synthesize PDMA

Figure 2013106850170100002DEST_PATH_IMAGE005

reaction equation:

By little strand transfer agent CTA (1.0984 g, 4.62 mmol), monomer DMA (N, N-DMAA) (37.06 g, 0.373 mol), be dissolved in 74.12 mL N, in dinethylformamide (DMF), nitrogen bubble deoxygenation 40 min under condition of ice bath, join the oil bath pan interior (R=500 r/min) of 70 ℃, after temperature stabilization, add 200 L AIBN (azodiisobutyronitrile) (0.015g, 0.09 mmol), reaction 3 h, ice bath quencher.Product is precipitated in ether to centrifugation.After centrifugation is complete, removal supernatant, collects lower sediment, dissolves, then use ether sedimentation with THF, repeats THF-ether process three times, by the vacuum drying of final gained precipitation, finally obtains 22.78 g yellow solids, and productive rate is 59.7%, and its structural formula is:

Through nuclear-magnetism (Bruker AV 500 MHz spectrometer) test, solvent is deuterochloroform, and the conversion ratio that calculates monomer reaction is 80.4 %.By gel permeation chromatograph (Waters Alliance e2695 GPC system) test molecule amount and dispersiveness, wherein concrete detecting information is, Waters styragel HR3 molecular weight ranges 5.0 * 10 ²-3.0 * 10 ⁴, HR4 molecular weight ranges 5.0 * 10 ³-6.0 * 10 ⁵, HR5 molecular weight ranges 5.0 * 10 ⁴-4.0 * 10 ⁶.DMF is mobile phase (LiBr that comprises 1mg/mL), and flow velocity is 0.8 mL/min, column temperature 65 ^oc, 2414 scattering measuring actuator temperatures are 45 ^oc, analysis software is Empower 2, polymetylmethacrylate is standard specimen, molecular weight ranges 2.4 * 10 ²-1.0 * 10 ⁶.GPC result records Mn=13 KDa, Mw/Mn=1.06; Through nuclear-magnetism, calculate Mn=6.6 KDa.

2. synthesize PNIPAM

Reaction equation:

By little strand transfer agent CTA (0.3621 g, 1.52 mmol), monomer NIPAM(N-N-isopropylacrylamide) (34.866 g, 0.308 mol), be dissolved in 69.73 mL N, in dinethylformamide (DMF), nitrogen bubble deoxygenation 50 min under condition of ice bath, join the oil bath pan interior (R=500 r/min) of 70 ℃, after temperature stabilization, add 200 L AIBN(azodiisobutyronitriles) (0.01 g, 0.06 mmol), react 3 h, ice bath quencher.Product is precipitated in ether to centrifugation.After centrifugation is complete, remove supernatant, collect lower sediment, with THF, dissolve, use again ether sedimentation, repeat THF (oxolane)-ether process three times, by the vacuum drying of final gained precipitation, finally obtain 17.82 g yellow solids, productive rate is 50.5 %, and its structural formula is:

Through nuclear-magnetism test, solvent is deuterated acetone, and the conversion ratio that calculates monomer reaction is 66.5 %.GPC result records Mn=23.1 KDa, Mw/Mn=1.10; Through nuclear-magnetism, calculate Mn=15.7 KDa.

The assorted arm star polymer P DMA-PNIPAM of synthetic different proportion

embodiment bis-:

The reaction equation of synthetic assorted wall star polymer:

syntheticpDMA-PNIPAM0.698

First by PNIPAM(1.9910 g, 0.13 mmol) joining 50 ml obtains in round-bottomed flask, the deionized water that adds 28.515 ml, in mixture of ice and water, ultrasonic 1 h dissolves completely, add again PDMA(0.8603 g, 0.13 mmol) and crosslinking agent 1,6-EDIA HDDA(0.8848 g, 3.91 mmol), solids content 10% w/v.Nitrogen bubble deoxygenation 30 min under condition of ice bath, being placed on magnetic stirring apparatus (R=600 r/min) stirs, first squeeze into 300 l ascorbic acid ASA (0.0230 g, 0.13 mmol), then squeeze into 300 l TBHP THBP (0.0118 g, 0.13 mmol), reaction 5 h.

Then with ultracentrifugation pipe MW=30000, rotating speed 5000 rpm rotating centrifugals are purified for several times, by surveying GPC, can find out that linear arms remains 3 %.Obtain PDMA-PNIPAM0.698.Its structural formula is:

embodiment tri-:

syntheticpDMA-PNIPAM0.743

First by PNIPAM(1.8189 g) join 50 ml and obtain in round-bottomed flask, the deionized water that adds 24.475 ml, in mixture of ice and water, ultrasonic 1 h dissolves completely, then adds PDMA(0.6287 g) and 1,6-EDIA HDDA(0.7274 g), solids content 10% w/v.Nitrogen bubble deoxygenation 20 min under condition of ice bath, being placed on magnetic stirring apparatus (R=1000 r/min) stirs, first enter 200 l ascorbic acid ASA (0.0189 g), then squeeze into 200 l TBHP THBP (0.0097 g), react 4 h, obtain PDMA-PNIPAM0.743.Its structural formula is:

embodiment tetra-:

syntheticpDMA-PNIPAM0.634

First by PNIPAM(1.5100 g) join 50 ml and obtain in round-bottomed flask, the deionized water that adds 23.800 ml, in mixture of ice and water, ultrasonic 1 h dissolves completely, then adds PDMA(0.8700 g) and 1,6-EDIA HDDA(0.7830 g), solids content 10% w/v.Nitrogen bubble deoxygenation 25 min under condition of ice bath, being placed on magnetic stirring apparatus (R=1000 r/min) stirs, first enter 200 l ascorbic acid ASA (0.0203 g), then squeeze into 200 l TBHP THBP (0.0104 g), react 4 h, obtain PDMA-PNIPAM0.634.

Its structural formula is:

The synthetic concrete data of the assorted arm star polymer of three kinds of different thermal sensitivity are as table 1:

Note: solids content is 10% w/v, the crosslinking agent HDDA that all adds 15 times, initator ascorbic acid and the TBHP of 0.5 times, be mol ratio: [PDMA+PNIPAM]: [HDDA] (1,6-EDIA): [ASA] (ascorbic acid): [t-BuOOH] (TBHP)=1:15:0.5:0.5, solvent is deionized water.

assorted arm CCS polymer name:while reacting with PNIPAM, account for to such an extent that mass ratio represents, by synthetic order, be respectively PDMA-PNIPAM0.698, PDMA-PNIPAM0.743, PDMA-PNIPAM0.634

the assorted star-like high molecular emulsifying property of arm star of research thermal sensitivity:

Emulsification condition: total emulsion volume is 1.5 mL, emulsive rate is controlled by high-speed stirred instrument (model Polytron PT 1200E homogenizer, rotary head diameter 7 mm), and emulsifying manner is within 60 seconds, to finish in the emulsification of maximum (top) speed place.

Emulsification scheme:

1. fixing emulsifier concentration, increases the volume fraction of oil phase dodecane gradually, inquires into its emulsifying effectiveness, if Fig. 8 is for being 0.50 wt% when the assorted arm star polymer concentration of thermal sensitivity, increases the emulsion photo of its formation with oil phase dodecane volume fraction

2., when discussion energy oil emulsion phase volume fraction reaches 80%, the least concentration of required emulsifying agent, as Fig. 9.

the star-like high molecular intelligent discussion scheme of thermal sensitivity:

Research method:

1. temperature is to the 0.5 star-like high molecular grain diameter influence of wt% thermal sensitivity, Fig. 4, and 5,6 show, PDMA-PNIPAM0.698, PDMA-PNIPAM0.743, the assorted high molecular cloud point of arm of PDMA-PNIPAM0.634 thermal sensitivity is respectively 35 ℃, and 36 ℃, 34 ℃.

2. when temperature is higher than 40 ℃, emulsifying agent just can become gel in very low concentration self, when reducing temperature, becomes rapidly again flowable state, and Fig. 7 shows

3. when temperature is higher than 40 ℃, when oil phase volume fraction is lower (as 30%, 50%), emulsion just can become gel, and Figure 10 shows

4. change the ratio of PDMA and PNIPAM, obtain different star polymers, by identical method, study, obtain as following table result.

Note: wherein in CCS, PDMA and PNIPAM ratio are by surveying nuclear-magnetism in heavy water, integral and calculating gained; Cloud point is tested gained by DLS.

The monomer that can form water soluble polymer arm has a lot, the following is the embodiment of the emulsifying agent of water-soluble monomer formation:

1. monomer M EA(acrylic acid 2-methoxyl group ethyl ester) and PEGA(polyethylene glycol adipate) synthetic Linear Polymer arm P (MEA ₈₀-co-PEGA ₂₀), linear arms P (MEA ₅₆-co-PEGA ₉), linear arms P (MEA ₇₄-co-PEGA ₈); With synthetic corresponding star polymer S (16 nm, 51 of corresponding linear arms ^oc), S (35 nm, 40 ^oc), S (19 nm, 31 ^oc); Various star polymers are as emulsifying agent, and emulsification result is as following table:

2. monomer DMA (N,N-DMAA) and MEA(acrylic acid 2-methoxyl group ethyl ester) synthetic Linear Polymer arm PDMA respectively, PMEA; With the synthetic star polymers CCS PDMA of two kinds of macromolecule arms ₁₅, CCS (PMEA24), CCS (PDMA10-PMEA8), CCS (PDMA12-PMEA5), CCS (PDMA7-PMEA10); Various star polymers are as emulsifying agent, and emulsification result is as Figure 12.

Claims

1. A heat-sensitive star polymer emulsifier, characterized in that the polymer emulsifier is formed by a heat-sensitive polymer linear arm and a water-soluble polymer linear arm by a heterogeneous polymerization cross-linking agent to form a nuclear cross-linked star polymer, The molar ratio of the polymer linear arm to the cross-linking agent is 3:30, and the molar ratio of the water-soluble polymer linear arm to the heat-sensitive polymer linear arm is 1:0.75~1.25; the degree of polymerization of the two polymer linear arms is 60~150.

2. The heat-sensitive star polymer emulsifier according to claim 1, characterized in that the monomer used to form the heat-sensitive polymer arm is: N-isopropylacrylamide NIPAM.

3. The heat-sensitive star polymer emulsifier according to claim 1, characterized in that the monomer forming the linear arm of the water-soluble polymer is: N, N-dimethylacrylamide DMA, polyethylene glycol Methyl ether methacrylate PPEGMA or polyethylene glycol methyl ether acrylate PEGA.

4. The thermosensitive star polymer emulsifier according to claim 1, characterized in that said crosslinking agent is: N , N '-methylenebisacrylamide, ethylene glycol diacrylate, 1,3 -Butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, tris(ethylene glycol) diacrylate, ethylene glycol dimethacrylate, 1,3-Butanediol Dimethacrylate, 1,4-Butanediol Dimethacrylate, 1,6-Hexanediol Dimethacrylate, or Tris(ethylene glycol)dimethacrylate ester.

5. a method for preparing the heat-sensitive star polymer emulsifier according to any one of claims 1, 2, 3 or 4, is characterized in that the concrete steps of the method are:

A. The chain transfer agent (methyl 2 - (((ethylthio) thiocarbonyl) thio) ethyl propionate), thermosensitive polymer monomer, oil-soluble initiator AIBN according to 1: (80 ~ 200 ): (0.02-0.04) molar ratio is added to the solvent, under an inert atmosphere, react at 70 ° C for 3-4 hours, after the polymerization is completed, the polymer is purified to obtain a heat-sensitive polymer arm;

B. The chain transfer agent (methyl 2 - (((ethylthio) thiocarbonyl) thio) ethyl propionate), thermosensitive polymer monomer, oil-soluble initiator azobisisobutyronitrile AIBN according to 1:(80~200):(0.02~0.04) molar ratio is added to the solvent, and reacted at 70°C for 3~4 hours under an inert atmosphere. After the polymerization is completed, the polymer is purified to obtain a water-soluble polymer arm;

C. The two kinds of star polymer linear arms prepared in step A and step B, cross-linking agent, and water-soluble initiator V50 are added to water according to the molar ratio of 1:(3～30):(0.01～1.0) , and control the solid content to 1-50 wt%. Under an inert atmosphere, heat at 70°C for 4-5 hours to prepare a nuclear cross-linked star-shaped polymer, and centrifugally purify to obtain a pure heat-sensitive star-shaped polymer. emulsifier.