Organoboronium amphiphilic block copolymers

A new class of amphiphilic organometallic block copolymers with cationic organoboron pendant groups was developed. Selective replacement of one of the bromine substitutents on each boryl group of the block copolymer PSBBr₂‐b‐PS with an organometallic reagent ArM (ArM = 2,4,6‐trimethylphenyl copper, 4‐t‐butylphenyltrimethyl tin) followed by treatment with 2,2′‐bipyridine gave the novel block copolymers [ 3Ar ](Br)_n as light yellow solid materials that show good stability in air and moisture and high solubility in most organic solvents. Their structure and composition were confirmed by multinuclear NMR, GPC, and elemental analysis. Highly regular micellar aggregates form in block‐selective solvents (e.g., MeOH, toluene) as demonstrated by ¹H NMR, dynamic light scattering, and transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6612–6618, 2009     

Environmentally responsive micelles from polystyrene–poly[bis(potassium carboxylatophenoxy)phosphazene] block copolymers

Amphiphilic diblock copolymers that contained hydrophilic poly[bis(potassium carboxylatophenoxy)phosphazene] segments and hydrophobic polystyrene sections were synthesized via the controlled cationic polymerization of Cl₃P?NSiMe₃ with a polystyrenyl–phosphoranimine as a macromolecular terminator. These block copolymers self‐associated in aqueous media to form micellar structures which were investigated by fluorescence spectroscopy, dynamic light scattering, and transmission electron microscopy. The size and shape of the micelles were not affected by the introduction of different monovalent cations (Li⁺, K⁺, Na⁺, and Cs⁺) into the stable micellar solutions. However, exposure to divalent cations induced intermicellar crosslinking through carboxylate groups, which caused precipitation of the ionically crosslinked aggregates from solution. This micelle‐coupling behavior was reversible: the subsequent addition of monovalent cations caused the redispersion of the polystyrene‐block‐poly[bis(potassium carboxylatophenoxy)phosphazene] (PS–KPCPP) block copolymers into a stable micellar solution. Aqueous micellar solutions of PS–KPCPP copolymers also showed pH‐dependent behavior. These attributes make PS–KPCPP block copolymers suitable for studies of guest retention and release in response to ion charge and pH. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2912–2920, 2005     

Synthesis and chiroptical properties of chiral binaphthyl‐containing polyfluorene derivatives

New chiral binaphthyl‐containing polyfluorene (PF) derivatives, PFOH , PFMOM , and PFP , bearing different binaphthyl units ((S)‐2,2′‐bis(methoxymethoxy)‐1,1′‐binaphthyl for PFMOM , (S)‐1,1′‐binaphthyl‐2,2′‐diol for PFOH , and (S)‐2,2′‐bis(diphenylphosphinyl)‐1,1′‐binaphthyl for PFP ) in the backbone have been designed and synthesized through Pd‐catalyzed Suzuki polycondensation. Their properties have been investigated in detail by ¹H NMR, ¹³C NMR, TGA, DSC, UV–vis, photoluminescence (in solutions, in thin films before and after annealing), and circular dichroism (CD) spectroscopic methods compared with poly(9,9‐dihexylfluorene‐2,7‐diyl) ( PF ). The resulting copolymers possessed excellent solubility in organic solvents and emitted strong blue light. The phosphine oxide‐containing copolymers PFP and PFMOM exhibited higher quantum yields and better thermal spectral stability in comparison with PF . All the copolymers exhibited obviously the linearly polarized photoluminescent properties both in solutions and in solid states. High emission polarization ratios (R_PL) of PFP were observed with no obvious decrease upon thermal annealing. In addition, investigation of the CD spectroscopic properties of these copolymers in THF solutions indicated that the chirality of the binaphthyls could be transferred to the whole PF backbone. All these results demonstrated that introduction of the chiral binaphthyls, particularly BINAPO, into the backbone could effectively improve the performances of the copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Preparation of amphiphilic statistical copolymers of 2‐hydroxyethyl methacrylate with 2‐diethylaminoethyl methacrylate,precursors of water‐soluble copolymers

Statistical copolymers of 2‐hydroxyethyl methacrylate (HEMA) and 2‐diethylaminoethyl methacrylate (DEA) were synthesized at 50 °C by free‐radical copolymerization in bulk and in a 3 mol L^?1 N,N′‐dimethylformamide solution with 2,2′‐azobisisobutyronitrile as an initiator. The solvent effect on the apparent monomer reactivity ratios was attributed to the different aggregation states of HEMA monomer in the different solvents. The copolymers obtained were water‐insoluble at a neutral pH but soluble in an acidic medium when the molar fraction of the DEA content was higher than 0.5. The quaternization of DEA residues increased the hydrophilic character of the copolymers, and they became water‐soluble at a neutral pH when the HEMA content was lower than 0.25. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2427–2434, 2002     

SYNTHESIS OF AMPHIPHILIC COIL-ROD-COIL BLOCK COPOLYMERS USING ATOM TRANSFER RADICAL POLYMERIZATION

ABSTRACT

Coil-rod-coil block copolymers composed from luminescent rigid units and acrylate flexible blocks have been synthesized using atom transfer radical polymerization. α,ω-Difunctionalized oligophenylenes properly modified to act as ATRP initiators have been used for the polymerization of the various acrylates. Copolymers with controlled shape and in some cases, relatively low polydispersities have been obtained as proved by size exclusion chromatography and NMR. In cases, where t-butyl acrylate blocks have been used as the flexible part, selective hydrolysis resulted in coil-rod-coil copolymers containing poly(acrylic acid) blocks. The solution behavior of the synthesized copolymers was explored in various solvents. The poly(acrylic acid) copolymers in aqueous solutions form large aggregates, while in organic selective solvents for the flexible block, monomolecular micelles seem to be formed.     

NEW POLYMER SYNTHESES. XIII. SYNTHESIS AND CHARACTERIZATION OF NOVEL POLYKETONES VIA FRIEDEL-CRAFTS REACTION AND BASED ON DIARYLIDENE DERIVATIVES

ABSTRACT

An interesting new class of polyketones based on diarylidene derivatives were synthesized by Friedel-Crafts reaction of 2,7-dibenzylidenecycloheptanone (I) and dibenzylideneacetone (II) monomers, with different diacid chlorids including: isophthalic, terephthalic, 3,3′-azodibenzoic, 4,4′-azodibenzoic, biphenic, adipic, sebacic and oxalic diacids in dry dichloromethane solvent and AlCl₃ catalyst. The model compounds were synthesized by reacting I and II with benzoyl chloride and characterized by ¹H-NMR, IR and elemental analyses. The polyketones were insoluble in most organic solvents but dissolved easily in concentrated sulfuric acid. The thermal properties of these polymers were evaluated and correlated to their structural units by TGA, DTG measurements and had inherent viscosity up to 0.36–0.84 dI/g. The crystallinity of some polymers were tested by X-ray analysis. The electronic spectra of selected examples were measured in DMSO solution and the morphological properties were detected by SEM.     

Novel electroactive poly(arylene ether sulfone) copolymers containing pendant oligoaniline groups: Synthesis and properties

We present a series of novel poly(arylene ether sulfone) copolymers containing pendant oligoaniline groups. A novel monomer containing oligoaniline, 2,6‐difluorobenzoyl aniline tetramer (DFAT), was synthesized by reaction of 2,6‐difluorobenzoyl chloride and parent aniline tetramer and incorporated into the aforementioned copolymers via direct copolymerization with 4,4′‐dichlorodiphenyl sulfone (DCDPS), and 4,4′‐isopropylidene diphenol (BPA) using N,N′‐dimethylacetamide as solvent. The structures of these copolymers were confirmed by FTIR, ¹H NMR, and GPC. Spectral analysis of the copolymers in different oxidation states was investigated via UV‐visible spectra. The copolymers exhibited outstanding thermal stability and good solubility in various organic solvents. Their electroactivity, explored with cyclic voltammetry, was found to increase as the content of oligoaniline in the polymer increased. The electric and dielectric properties of the copolymers were also studied in detail. The electrochromic performance of the copolymers was investigated by electrochromic photographs and transmittance spectra; the color of the copolymer thin films changes from grey (at 0.0 V), to green (at 0.4 V), to blue (at 0.6 V) and to pearl blue (at 1.0 V) and the maximum transmittance change (ΔT) at 700 nm is 42.6% (90.7% ? 48.1%). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

New Polymer Syntheses. 80. Linear,Star-Shaped,and Hyperbranched Poly(Ester-Amide)s from Silicon-Mediated One-Pot Condensations of 3-Acetoxy-, 3,5-Bisacetoxybenzoic Acid,and 3-Aminobenzoic Acid

Abstract

Acylation of N,O-bistrimethylsilyl-3-aminobenzoic acid with 3-acetoxybenzoylchloride yielded the trimethylsilylester of N-(3′-acetoxybenzoyl)-3-aminobenzoic acid, which was polycondensed in situ at 260 or 280°C. Cocondensation with acetylated tetraphenols yielded four-arm star copolymers with a random or preferentially alternating sequence of 3-hydroxy and 3-aminobenzoyl units. Due to ester-amide exchange detected by ¹H- and ¹³C-NMR spectroscopy, the sequences were never perfectly alternating. Methyl groups attached to the star centers allowed the determination of degrees of polymerization by ¹H-NMR spectroscopy. Acylation of N,O-bistrimethylsilyl-3-amino benzoic acid with 3,5-bisacetoxybenzoylchloride yielded a trifunctional monomer, the polycondensation of which yielded a hyperbranched poly(ester-amide). By cocondensation of the trifunctional monomer with acetylated tetraphenyl, star-shaped poly(ester-amide)s with four hyperbranched star arms were obtained. All these poly(ester-amide)s are amorphous materials with glass-transition temperatures in the 190–200°C range and good solubility in polar organic solvents.     

Characterization of amphiphilic hydrocarbon modified Poly(ethylene glycol) synthesized through ring-opening reaction of 2-(1-octadecenyl)succinic anhydride

Poly(ethylene glycol) (PEG) triblock and diblock amphiphilic block copolymers were synthesized from poly(ethylene glycol) and poly(ethylene glycol) monomethyl ether, respectively. The hydroxyl groups of PEG readily react with 2-(1-octadecenyl) succinic anhydride (OSA) at 140 °C through ring-opening reaction of the succinic anhydride. Both the PEG-OSA diblock and triblock copolymers are produced without use of any solvent or catalyst. The molecular structure of the copolymers was characterized by ¹H NMR and FTIR spectroscopy, and the thermal properties by DSC. The behavior of the copolymers in selective and nonselective solvents was studied by ¹H NMR spectroscopy in deuterium oxide and d-chloroform. The aggregation of the polymers in water was studied with a particle size analyzer and a transmission electron microscope (TEM) in bright field mode. The results show that the hydrophobic C₁₈ chain with intramolecular succinic anhydride linker can be attached to the hydrophilic PEG chain, an ester bond forming between the blocks. The copolymers exhibit flexible, liquid-like hydrophobic blocks even in water, which is a nonsolvent for OSA. PEG-OSA block copolymers self-organize in water, forming micellar polymer aggregates in nanoscale.     

Cleavage of polystyrene‐b‐poly(ethylene oxide) block copolymers with a trithiocarbonate linkage in solutions

In this work, the polystyrene‐b‐poly(ethylene oxide) (PS‐b‐PEO) block copolymers with a trithiocarbonate group between the blocks were prepared by polymerization of styrene in the presence of a trithiocarbonate reversible addition fragmentation chain transfer (RAFT) agent connected with PEO. Decomposition of the trithiocarbonate group by UV irradiation was investigated in three different types of solvent: tetrahydrofuran (THF, common solvent for both blocks), cyclohexane/dioxane mixture (selective solvent for the PS block) and N,N‐dimethylformamide (DMF)/ethanol mixture (selective solvent for the PEO block). It is found that cleavage of the block copolymers can take place in all these three solvents and the cleavage ratio ranges from 76 to 86%. The micellar morphologies in selective solvents before and after cleavage were examined. It is observed that the size of the micelles is reduced after cleavage and sometimes aggregation of the micelles occurs due to removal of the corona of micelles. It shows that this work provides a facile and general method for synthesis of cleavable block copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3834–3840, 2010     

Synthesis and aqueous solution properties of hydrophobically modified anionic acrylamide copolymers

In this investigation, hydrophobically modified polyacrylamide with low amounts of anionic long‐chain alkyl was synthesized by the free radical polymerization in deionized water. This water‐soluble copolymerization method is more convenient compared with the traditional micellar copolymerization methods. The copolymers were characterized using Fourier transform infrared, ¹H NMR, and the molecular weight and polydispersity were determined using gel permeation chromatography. The solution behavior of the copolymers was studied as a function of composition, pH, and added electrolytes. As NaCl was added to solutions of AM/C₁₁AM copolymers or pH was lowered, the shielding or elimination of electrostatic repulsions between carboxylate groups of the C₁₁AM unit lead to coil shrinkage. The steady shear viscosity and dynamic shear viscoelastic properties in semidilute, salt‐free aqueous solutions were conducted to examine the concentration effects on copolymers. In addition, the shear superimposed oscillation technique was used to probe the structural changes of the network under various stresses or shear conditions. We prepared hydrophobically modified polyacrylamide with N‐alkyl groups in the aqueous medium. The advantage of this method is that the production is pure without surfactants. These results suggest that the unique aqueous solution behavior of the copolymers is different from conventional hydrophobically associating acrylamide. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2465–2474, 2008     

The preparation and characterization of the cross-linked spherical, cylindrical, and vesicular micelles of poly(styrene-b-isoprene) diblock copolymers

PI cores of the micelles of poly(styrene-b-isoprene) (PS-b-PI) diblock copolymers, in PS selective solvents, were cross-linked with sulfur monochloride (S2Cl2). The cross-linked micellar structure was maintained after dialysis in THF (neutral solvent) and did not change during heating. Cross-linking brought about the opportunity for TEM images in a solution state; otherwise, the micellar structure would be destroyed (or changed) during the evaporation of the solvent on a carbon-coated copper grid. The Flory interaction parameter, chi, between the PI block and the solvent was controlled by mixing two selective solvents (DMP/toluene, DMP/DEP and DEP/DBP) which have different degrees of selectivity for the PS block, as well as heating the solutions. Two block copolymers, PS(7.2K)-b-PI(7.8K) and PS(5.5K)-b-PI(18.8K), were studied in order to clarify the effects of the relative chain length of each block on the micelle structure in the selective solvents. PS(7.2K)-b-PI(7.8K), which is nearly symmetric, showed only spherical micelles in the DMP/toluene mixture. The basic spherical micellar shape of PS(7.2K)-b-PI(7.8K) did not change with chi, while the size and aggregation number of the micelles increased as chi increased until 2.05 and then were saturated after that. PS(5.5K)-b-PI(18.8K), which is asymmetric, showed a structural change from spherical to cylindrical to vesicular micelles with an increase in the selectivity of the DMP/DEP and DEP/DBP mixtures (which was also confirmed by TEM and SAXS studies). Giant vesicular micelles with a diameter of approximately 2.5 microm were observed in high-selectivity solvents. The size of the vesicular micelle seemed to decrease as selectivity decreased. The systematic changes of the micellar structures of PS(5.5K)-b-PI(18.8K), via changes in solvent selectivity, could be demonstrated through TEM images, which were prepared by evaporating the solvent of the cross-linked micellar solution onto the carbon-coated grid after dialysis.     

Polycarbazole Copolymers from 3-(4-Fluorobenzoyl)carbazole and 4,4′-Biphenol via Combined C-N and C-O Coupling Reactions with Activated Difluorides

3-(4-Fluorobenzoyl)carbazole was synthesized by a Friedel-Crafts reaction of carbazole with 4-fluorobenzoylchloride. ¹H-NMR and MALDI-TOF MS confirmed the structure and the purity. Copolymers of these NH/OH-containing monomers were prepared with 4, 4′-biphenol and bis(4-fluorophenyl)sulfone as comonomers by combined C-O and C-N coupling reactions with activated difluorides. These copolymers were soluble in N-methylpyrrolidinone (NMP), dimethylsulfoxide (DMSO), N,N-dimethylacetamide (DMAc) and dimethylformamide (DMF). The inherent viscosities of the copolymers in NMP solutions at 30°C were all around 0.8 dL/g. They could be easily cast into tough films from NMP solutions. The copolymers exhibited T_gs ranging from 238°C to 282°C. Thermal stabilities by TGA showed no weight loss below 400°C and the temperatures of 5% weight loss ranged from 535°C to 558°C. The homopolymer of 3-(4-fluorobenzoyl)carbazole was insoluble in common solvents and had a T_g of 332°C, and temperature of 5% weight loss of 560°C. UV-VIS absorption and fluorescence of the polymers are also presented.     

Synthesis and characterization of amphiphilic diblock copolymers of methyl tri(ethylene glycol) vinyl ether and isobutyl vinyl ether

Water-soluble diblock copolymers of methyl tri(ethylene glycol) vinyl ether (hydrophilic block) and isobutyl vinyl ether (hydrophobic block) of different molecular weights and composition were synthesized by living cationic polymerization. The molecular weight and comonomer composition of these copolymers were determined by GPC and ¹H NMR spectroscopy, respectively. Aqueous solutions of the copolymers were characterized in terms of their micellar behavior using dynamic light scattering, aqueous GPC, and dye solubilization. All the copolymers formed aggregates with the exception of a diblock copolymer with only two hydrophobic monomer units. The micellar hydrodynamic size scaled with the 0.61 power of the number of hydrophobic units, in good agreement with a theoretical exponent of 0.73. An increase in the length of the hydrophobic block at constant hydrophilic block length or an increase in the overall polymer size at constant block length ratio both resulted in lower critical micelle concentrations (cmcs). The cloud points of 1% w/w aqueous solutions of the polymers were determined by turbidimetry. An increase in the length of the hydrophobic block at constant hydrophilic block length caused a decrease in the cloud points of the copolymers. However, an increase in the overall polymer size at constant block length ratio led to an increase in the cloud point. © 1996 John Wiley & Sons, Inc.     

Synthesis,micellization and gelation of temperature‐responsive star‐shaped block copolymers

A series of amphiphilic temperature‐responsive star‐shaped poly(D,L‐lactic‐co‐glycolic acid)‐b‐methoxy poly(ethylene glycol) (PLGA‐mPEG) block copolymers with different arm numbers were synthesized via the arm‐first method. Gel permeation chromatography data confirmed that star‐shaped PLGA‐mPEG copolymers had narrow polydispersity index, indicating the successful formation of star‐shaped block copolymers. Indirectly, the ¹H NMR spectra in two kinds of solvents and dye solubilization method had confirmed the formation of core‐shell micelles. Further, core‐shell micelles with sizes of about 30–50 nm were directly observed by transmission electron microscopy. Subsequently, the micellar sizes and distributions as a function of concentrations and temperature were measured. At various copolymer concentrations, individual micelles with size of 20–40 nm and grouped micelles with size of 600–700 nm were found. Micellar mechanism of star‐shaped block copolymers in aqueous solution was simultaneously discussed. In addition, sol–gel transition of star‐shaped block copolymers in water was also investigated via the inverting test method. The critical gel temperature (CGT) and critical gel concentration (CGC) values of two‐arm, three‐arm and four‐arm copolymer solutions were markedly higher than ones of one‐arm copolymer. Moreover, the same CGC values of copolymer solution with different molecular weight and the same arm composition were ~15 wt %, and CGT values increased from ~38 to ~47°C with increasing arm numbers. Finally, the temperature‐dependent micellar packing gelation mechanism of star‐shaped block copolymer was schematically illustrated. Copyright © 2013 John Wiley & Sons, Ltd.     

Solvent-dependent assembly of porous coordination polymers based on Keggin-type [SiW12O40]4–

Two coordination polymers (CPs) based on Keggin-type [SiW₁₂O₄₀]^4– (SiW₁₂), [Zn₂(bpy)₂(SiW₁₂O₄₀)(DMF)₈]·solvent (1) and [Zn₂(bpy)(SiW₁₂O₄₀)(DMA)₈]·2DMA (2) (bpy = 4,4′-bipyridine, DMF?=?N,N′-dimethylformamide; DMA?=?N,N′-dimethylacetamide), have been solvo-thermally synthesized and characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectra, elemental analyses and thermogravimetric analyses. Both 1 and 2 are synthesized under similar conditions except DMF and DMA were used as the solvents for 1 and 2, respectively. Structural studies reveal that the supramolecular framework of 1 contains pumpkin-like voids, while 2 has a non-porous supramolecular framework. These results show that solvents play an important role in construction of the POM-based CPs. The luminescent properties for 1 and 2 have also been investigated.     

Conformational behavior of styrene–p-chlorostyrene triblock copolymers in dilute solutions. I. Composition dependence of conformational behavior

Dilute solution properties of (styrene-p-chlorostyrene) triblock copolymers in various solvents were studied over a wide range of molecular weight and composition. Viscosity and osmotic pressure results indicate that the conformational behavior of the B_mA_nB_m and A_mB_nA_m copolymers (A = styrene; B = p-chlorostyrene; m and n denote the number of units) are similar in nonselective solvents such as toluene and 2-butanone, but different in selective solvents such as carbon tetrachloride and cumene. Short-range and long-range interaction parameters of the block copolymers were determined by applying the Stockmayer–Fixman method to viscosity data and also by application of the equation relating the osmotic virial coefficient and the excluded volume. The results show that the unperturbed dimensions of the block copolymers vary linearly with composition, and long-range interaction parameters in nonselective solvents can be expressed by those of the parent homopolymers, the chemical composition, and values of the interaction parameter β_AB between styrene and p-chlorostyrene monomeric units.     

Size Exclusion Chromatography of Associating Systems. I. The Theoretical Model

Abstract

Block copolymers in dilute solutions in selective solvents form micelles via closed association which is characterized by equilibrium between unimer and n-mer. A simple theoretical model has been proposed describing the behavior of such a system in the size exclusion chromatography (SEC). Chromatograms have been calculated varying association number and relative rates of association and dissociation. The results are compared with those of Coll's theory for SEC of surfactants and Gilbert's theory of associating systems.     

Non-ionic amphiphilic block copolymers by RAFT-polymerization and their self-organization

Water-soluble, amphiphilic diblock copolymers were synthesized by reversible addition fragmentation chain transfer polymerization. They consist of poly(butyl acrylate) as hydrophobic block with a low glass transition temperature and three different nonionic water-soluble blocks, namely, the classical hydrophilic block poly(dimethylacrylamide), the strongly hydrophilic poly(acryloyloxyethyl methylsulfoxide), and the thermally sensitive poly(N-acryloylpyrrolidine). Aqueous micellar solutions of the block copolymers were prepared and characterized by static and dynamic light scattering analysis (DLS and SLS). No critical micelle concentration could be detected. The micellization was thermodynamically favored, although kinetically slow, exhibiting a marked dependence on the preparation conditions. The polymers formed micelles with a hydrodynamic diameter from 20 to 100 nm, which were stable upon dilution. The micellar size was correlated with the composition of the block copolymers and their overall molar mass. The micelles formed with the two most hydrophilic blocks were particularly stable upon temperature cycles, whereas the thermally sensitive poly(N-acryloylpyrrolidine) block showed a temperature-induced precipitation. According to combined SLS and DLS analysis, the micelles exhibited an elongated shape such as rods or worms. It should be noted that the block copolymers with the most hydrophilic poly(sulfoxide) block formed inverse micelles in certain organic solvents.     

Temperature/Light Dual‐Responsive Inclusion Complexes of α‐Cyclodextrins and Azobenzene‐Containing Polymers

Three kinds of photoresponsive copolymers with azobenzene side chains were synthesized by radical polymerization of N‐4‐phenylazophenylacrylamide (PAPA) with N‐isopropylacrylamide (NIPAM), N,N‐diethylacrylamide (DEAM) or N,N‐dimethylacrylamide (DMAM) respectively. Their structures were characterized by FT‐IR, ¹H‐NMR and UV/Vis spectroscopy. Their reversible photoresponses were studied with or without α‐cyclodextrin (α‐CD), which showed that both the copolymers and their inclusion complexes with α‐CD underwent rapid photoisomerization. The lower critical solution temperature (LCST) of the copolymers and their inclusion complexes with α‐CD were investigated by cloud point measurement, which showed that the LCST of three kinds of copolymers increased largely after adding α‐CD. After UV irradiation on the solutions of copolymers and their inclusion complexes, the LCST of the copolymers increased slightly with the absence of α‐CD, while decreased largely with the presence of α‐CD. Furthermore, the LCST reverted to its originality after visible light irradiation. This change of LCST could be reversibly controlled by UV and visible light irradiation alternately. In particular, in the copolymer of PAPA and DMAM, the reversible water solubility of the inclusion complexes could be triggered by alternating UV and visible light irradiation.