Characterization and water vapor sorption property of ABA‐type triblock copolymers derived from polyimide and poly(methyl methacrylate)

The characterization of ABA‐type triblock copolymer films derived from polyimide (PI) macroinitiator and poly(methyl methacrylate) (PMMA) synthesized by atom transfer radical polymerization was investigated by focusing on different block lengths of PMMA. The hydrophobic property tends to increase with increasing PMMA content in the triblock copolymers, while the PMMA blocks enhance the charge transfer interaction between the PI segments. The water vapor sorption measurement of triblock copolymers was determined at 35 °C. The water vapor solubility of triblock copolymers tends to decrease with increasing PMMA content. In addition, linear correlations were observed between the solubility and polymer‐free volume and polymer molecular polarity in triblock copolymers as well as in other conventional polymer families. According to Zimm?Lundberg analysis, the PMMA block segments in the triblock copolymers accelerate water vapor clustering due to the high mobility of PMMA. The mobility of PMMA block segments strongly affected not only physical properties but also the water vapor solubility of the triblock copolymers. The ABA triblock copolymerization composed of PI and PMMA is one of the effective ways to improve the hydrophobic property. © 2013 Society of Chemical Industry     

Gas transport and optical properties of ABA‐type triblock copolymers designed using fluorine‐containing polyimide macroinitiators with methyl methacrylate

4,4'‐(Hexafluoroisopropylidene) diphthalic anhydride 2,3,5,6‐tetramethyl‐1,4‐phenylenediamine (6FDA‐TeMPD) polyimide macroinitiator was synthesized and reacted with poly(methyl methacrylate) (PMMA) to form an ABA‐type triblock copolymer by atom transfer radical polymerization. The effect of the ABA‐type triblock copolymer structure on solid, thermal, optical and gas transport properties was systematically investigated and compared with the physical blend polymer. The blend polymer was cloudy, whereas the triblock copolymer was colorless and transparent. The PMMA component decomposition temperature for the triblock copolymer slightly shifted to higher temperature, while its gas barrier property was higher than the blend polymer. The refractive index and the gas permeability decreased while maintaining the heat resistance by a high nanoscale distribution of both polymer components. The 6FDA‐TeMPD/PMMA ABA‐type triblock copolymer can be described as a polymer material with high heat resistance, high gas barrier property and low refractive index amongst existing polymers. © 2013 Society of Chemical Industry     

Surface microphase separation in PDMS‐b‐PMMA‐b‐PHFBMA triblock copolymer films

Well‐defined poly(dimethylsiloxane)‐block‐poly(methyl methacrylate)‐block‐poly(2,2,3,3,4,4,4‐heptafluorobutyl methacrylate) (PDMS‐b‐PMMA‐b‐PHFBMA) triblock copolymers were synthesized via atom transfer radical polymerization (ATRP). Surface microphase separation in the PDMS‐b‐PMMA‐b‐PHFBMA triblock copolymer films was investigated. The microstructure of the block copolymers was investigated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Surface composition was studied by X‐ray photoelectron spectroscopy (XPS). The chemical composition at the surface was determined by the surface microphase separation in the PDMS‐b‐PMMA‐b‐PHFBMA triblock copolymer films. The increase of the PHFBMA content could strengthen the microphase separation behavior in the PDMS‐b‐PMMA‐b‐PHFBMA triblock copolymer films and reduce their surface tension. Comparison between the PDMS‐b‐PMMA‐b‐PHFBMA triblock copolymers and the PDMS‐b‐PHFBMA diblock copolymers showed that the introduction of the PMMA segments promote the fluorine segregation onto the surface and decrease the fluorine content in the copolymers with low surface energy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of ABA‐type triblock copolymers derived from polyimide and poly(2‐methyl‐2‐adamantyl methacrylate)

ABA‐type triblock copolymers derived from 4,4‐(hexafluoroisopropylidene)diphthalic anhydride‐2,3,5,6‐tetramethyl‐1,4‐phenylenediamine and 2‐methyl‐2‐adamantyl methacrylate (2‐MAdMA) were synthesized via atom transfer radical polymerization. The component ratios of polyimide (PI) and poly(2‐MAdMA) (PMAdMA) were about 8/2, 6/4 and 3/7, as determined using ¹H NMR spectroscopy and thermogravimetric analysis (TGA). The film structure of the triblock copolymers was dependent on the PI structure. Hydrophobicity increased as the component ratio of PMAdMA increased. Based on TGA, three‐step decomposition behaviors of all triblock copolymers derived from PI and PMAdMA in nitrogen and air atmosphere were observed. The gas permeability of the triblock copolymers was lower than that of PI. This finding can be attributed to the decrease in fractional free volume by the adamantane component and the decrease in permeability of the triblock copolymers compared with PI. The dielectric constant of the triblock copolymers was lower than that of PI. The dielectric constant was dependent on molar volume and molar porlarizability, and the dielectric constant derived from the symmetric structure of adamantane was reduced. The ABA‐type triblock copolymers derived from PI and PMAdMA can be considered as new polymer materials with high hydrophobicity, high H₂/CO₂ selectivity and low dielectric constant. © 2013 Society of Chemical Industry     

Synthesis and characterization of diblock,triblock, and multiblock copolymers containing poly(3‐hydroxy butyrate) units

A poly[(R,S)‐3‐hydroxybutyrate] macroinitiator (PHB‐MI) was obtained through the condensation reaction of poly[(R,S)‐3‐hydroxybutyrate] (PHB) oligomers containing dihydroxyl end functionalities with 4,4′‐azobis(4‐cyanopentanoyl chloride). The PHB‐MI obtained in this way had hydroxyl groups at two end of the polymer chain and an internal azo group. The synthesis of ABA‐type PHB‐b‐PMMA block copolymers [where A is poly(methyl methacrylate) (PMMA) and B is PHB] via PHB‐MI was accomplished in two steps. First, multiblock active copolymers with azo groups (PMMA‐PHB‐MI) were prepared through the redox free‐radical polymerization of methyl methacrylate (MMA) with a PHB‐MI/Ce(IV) redox system in aqueous nitric acid at 40°C. Second, PMMA‐PHB‐MI was used in the thermal polymerization of MMA at 60°C to obtain PHB‐b‐PMMA. When styrene (S) was used instead of MMA in the second step, ABCBA‐type PMMA‐b‐PHB‐b‐PS multiblock copolymers [where C is polystyrene (PS)] were obtained. In addition, the direct thermal polymerization of the monomers (MMA or S) via PHB‐MI provided AB‐type diblocks copolymers with MMA and BCB‐type triblock copolymers with S. The macroinitiators and block copolymers were characterized with ultraviolet–visible spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, cryoscopic measurements, and thermogravimetric analysis. The increases in the intrinsic viscosity and fractional precipitation confirmed that a block copolymer had been obtained. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1789–1796, 2004     

Nanostructured polymer blends based on polystyrene‐b‐polybutadiene‐b‐poly(methyl methacrylate) triblock copolymers modified with polystyrene and/or poly(methyl methacrylate) homopolymers

Morphologies of polymer blends based on polystyrene‐b‐ polybutadiene‐b ‐poly(methyl methacrylate) (SBM) triblock copolymer were predicted, adopting the phase diagram proposed by Stadler and co‐workers for neat SBM block copolymer, and were experimentally proved using atomic force microscopy. All investigated polymer blends based on SBM triblock copolymer modified with polystyrene (PS) and/or poly(methyl methacrylate) (PMMA) homopolymers showed the expected nanostructures. For polymer blends of symmetric SBM‐1 triblock copolymer with PS homopolymer, the cylinders in cylinders core?shell morphology and the perforated lamellae morphology were obtained. Moreover, modifying the same SBM‐1 triblock copolymer with both PS and PMMA homopolymers the cylinders at cylinders morphology was reached. The predictions for morphologies of blends based on asymmetric SBM‐2 triblock copolymer were also confirmed experimentally, visualizing a spheres over spheres structure. This work presents an easy way of using PS and/or PMMA homopolymers for preparing nanostructured polymer blends based on SBM triblock copolymers with desired morphologies, similar to those of neat SBM block copolymers. © 2017 Society of Chemical Industry     

Synthesis and properties of liquid‐ crystalline triblock copolymers by ATRP,having electron‐transporting thiadiazole unit

ABA‐type block copolymers composed of 2,5‐diphenyl‐1,3,4‐thiadiazole (DPTD) oligoester and poly(methyl methacrylate) (PMMA) segments (M_n = 16 200 and 23 000) were synthesized by atom‐transfer radical polymerization and their liquid‐crystalline (LC) and photoluminescence (PL) properties were examined. The structures of block copolymers were identified by Fourier transform infrared and ¹H NMR spectroscopies. Differential scanning calorimetry measurement, polarizing microscopy observation and wide‐angle X‐ray analysis revealed that the block copolymers form thermotropic LC phase (smectic C) independent of molecular weights of PMMA segments, but a model polymer (PMMA segments having the DPTD unit in the central part) has no LC melt. Solution and solid‐state PL spectra indicated that all the block copolymers display blue emission arising from the DPTD unit. Their quantum yields are 17–21%, which increase with the PMMA chain lengths. The block copolymers have good aligned structures in the LC states, but their order parameter (S) values in sheared LC states were lower than those in the sheared LC compounds. The PL properties in the LC states were independent of the LC aligned structures. Cyclic voltammetry measurements showed that these block copolymers have deep HOMO levels compared with polymers composed of oxadiazole rings. Copyright © 2007 Society of Chemical Industry     

Hyperbranched–linear–hyperbranched ABA‐type block copolymers based on poly(ethylene oxide) and polyglycerol

BACKGROUND: Until recently, hyperbranched polymers were thought to be ill‐defined materials that were not useful as building blocks for well‐defined complex polymer architectures. It is a current challenge to develop strategies that offer rapid access to well‐defined hyperbranched block copolymers. RESULTS: A convenient three‐step protocol for the synthesis of double‐hydrophilic hyperbranched–linear–hyperbranched ABA‐type triblock copolymers based on poly(ethylene oxide) (PEO) and hyperbranched polyglycerol (hbPG) is presented. The Bola‐type polymers exhibiting an aliphatic polyether structure were prepared from a linear (lin) linPG‐b‐PEO‐b‐linPG precursor triblock. The materials exhibit low polydispersities (M_w/M_n) in the range 1.19–1.45. The molecular weights of the block copolymers range from 6300 to 26 200 g mol^?1, varying in the length of both the linear PEO chain as well as the hbPG segments. Detailed characterization of the thermal properties using differential scanning calorimetry demonstrates nanophase segregation of the blocks. CONCLUSION: The first example of well‐defined ABA hyperbranched–linear–hyperbranched triblock copolymers with PEO middle block and hbPG A‐blocks is presented. The biocompatible nature of the aliphatic polyether blocks renders these materials interesting for biomedical purposes. These new materials are also intriguing with respect to their supramolecular order and biomineralization properties. Copyright © 2009 Society of Chemical Industry     

Effects of thermal treatment on the CO2 sorption of triblockcopolymers derived from polyimide and poly(methylmethacrylate)

ABA‐type triblock copolymers were synthesized using 4,4‐(hexafluoroisopropylidene) diphthalic anhydride‐2,3,5,6‐tetramethyl‐1,4‐phenylenediamine (6FDA‐TeMPD) and poly(methyl methacrylate) (PMMA). The films were characterized by determining the effects of different content ratios and thermal decomposition of PMMA block on CO₂ sorption properties. TGA results showed that a thermal labile block can be completely decomposed under a previously reported thermal condition. SEM results presented that the asperity was micro‐phase separation caused by the PMMA block content rate. Numerous pores with sizes of approximately 10 to 50 nm were detected on Block(28/72) and Block(10/90). The isotherms of all films fitted the dual‐mode sorption model, and CO₂ sorption decreased with increased PMMA content rate. Infinite‐dilution CO₂ solubility depended on the Langmuir's site of each polymer because S_H0/S₀ of PI and Block(PI/PMMA) varied from 0.84 to 0.92 CO₂ affinity was increased by thermal treatment as indicated by the higher b and S₀ values of thermally treated films than those of nontreated films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42208.     

Preparation of PMMA–PS–PMMA via combination of anionic and photoinduced charge‐transfer polymerization

PMMA–PS–PMMA triblock copolymers were prepared by the combination of an anionic mechanism with charge‐transfer polymerization. Polystyrene with aromatic tertiary amino groups at both ends (PS_ba) was synthesized first by the reaction of a living polystyrene macrodianion with excess p‐(dimethylamino)benzaldehyde; then, the PS_ba was constituted into a binary system with benzophenone (BP) to initiate the polymerization of methyl methacrylate (MMA) under UV irradiation. The intermediate and resulting block copolymers were characterized by GPC, IR, and ¹H‐NMR. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2072–2076, 1999     

Synthesis and characterization of ABA‐type block copolymers of trimethylene carbonate and ϵ‐caprolactone

This paper describes the synthesis of a series of ABA‐type triblock copolymers of trimethylene carbonate and ?‐caprolactone with various molar ratios and analyses the thermal and mechanical properties of the resulting copolymers. The structures of the triblock copolymers were characterized by ¹H and ¹³C nuclear magnetic resonance spectroscopy, FT‐IR spectroscopy and gel permeation chromatography. Results obtained from the various characterization methods proves the successful synthesis of block copolymers of trimethylene carbonate and ?‐caprolactone. The thermal properties of the block copolymers were investigated by differential scanning calorimetry. The T_m and ΔH_m values of the copolymers decrease with increasing content of trimethylene carbonate units. Two T_gs were found in the copolymers. Furthermore, both of the T_g values increased with increasing content of trimethylene carbonate units. The mechanical properties of the resulting copolymers were studied by using a tensile tester. The results indicated that the mechanical properties of the block copolymers are related to the molar ratio of trimethylene carbonate and ?‐caprolactone in the copolymers, as well as the molecular weights of the resulting copolymers. The block copolymer with a molar composition of 50/50 possessed the highest tensile stress at maximum and modulus of elasticity. Block copolymers possessing different properties could be obtained by adjusting the copolymer compositions. Copyright © 2004 Society of Chemical Industry     

Preparation of highly syndiotactic block copolymers of methyl methacrylate and lauryl methacrylate and their characterization

Summary Highly syndiotactic diblock and triblock copolymers comprising lauryl methacrylate (LMA) and methyl methacrylate (MMA) with narrow molecular weight distributions were prepared by the living anionic polymerization with t-C₄H₉Li/(C₂H₅)₃Al in toluene at low temperature. The block copolymers were soluble in acetone which is a non-solvent for poly(lauryl methacrylate) (PLMA). ¹HNMR and vapor pressure osmometric analyses of the block copolymers indicated the aggregation of the copolymer in acetone through the interaction between PLMA blocks. Stereocomplex formation between the triblock copolymer and isotactic poly(methyl methacrylate) (PMMA) took place more effectively in solution than in the solid state.     

Synthesis of PMMA‐PTHF‐PMMA and PMMA‐PTHF‐PST linear and star block copolymers

Combination of cationic, redox free radical, and thermal free radical polymerizations was performed to obtain linear and star polytetramethylene oxide (poly‐THF)‐polymethyl methacrylate (PMMA)/polystyrene (PSt) multiblock copolymers. Cationic polymerization of THF was initiated by the mixture of AgSbF₆ and bis(4,4′ bromo‐methyl benzoyl) peroxide (BBP) or bis (3,5,3′,5′ dibromomethyl benzoyl) peroxide (BDBP) at 20°C to obtain linear and star poly‐THF initiators with M_w varying from 7,500 to 59,000 Da. Poly‐THF samples with hydroxyl ends were used in the methyl methacrylate (MMA) polymerization in the presence of Ce(IV) salt at 40°C to obtain poly(THF‐b‐MMA) block copolymers containing the peroxide group in the middle. Poly(MMA‐b‐THF) linear and star block copolymers having the peroxide group in the chain were used in the polymerization of methyl methacrylate (MMA) and styrene (St) at 80°C to obtain PMMA‐b‐PTHF‐b‐PMMA and PMMA‐b‐PTHF‐b‐PSt linear and star multiblock copolymers. Polymers obtained were characterizated by GPC, FT‐IR, DSC, TGA, ¹H‐NMR, and ¹³C‐NMR techniques and the fractional precipitation method. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 219–226, 2004     

Physical and mechanical properties of poly(methyl methacrylate)‐grafted natural rubber synthesized by methyl methacrylate photopolymerization initiated by N,N‐diethyldithiocarbamate functions previously created on natural rubber chains

Well‐defined poly(methyl methacrylate) (PMMA)‐grafted natural rubbers (NRs) were prepared to study the structure–property relationships. Syntheses were achieved by the photopolymerization of methyl methacrylate initiated by N,N‐diethyldithiocarbamate groups created beforehand in side positions on the NR chains. With this procedure, good control of the graft density and PMMA content could be obtained. Thermal, morphological, and mechanical properties of NR‐g‐PMMA copolymers were studied as a function of the NR/PMMA composition and graft density. NR‐g‐PMMAs containing 15–80% grafted PMMA showed characteristics of heterogeneous materials (characterized by two glass‐transition temperatures, those of PMMA and NR, in differential scanning calorimetry). Under these conditions, they developed the morphology of thermoplastic elastomers with PMMA nodules dispersed in the rubber matrix when the PMMA content was near 20%; conversely, they developed the morphology of softened thermoplastics with rubber nodules dispersed in PMMA when the PMMA content was near 80%. Graft copolymers containing about 20% PMMA remained essentially rubbery, but they were already different from pure NR. On the other hand, the thermal stability of NR wash improved after the introduction of PMMA grafts onto NR chains. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Self‐complementary multiple hydrogen bonding interactions increase the glass transition temperatures to supramolecular poly(methyl methacrylate) copolymers

We have prepared a series of poly(methyl methacrylate) (PMMA)‐based copolymers through free radical copolymerization of methyl methacrylate in the presence of 2‐ureido‐4[1H]‐pyrimidinone methyl methacrylate (UPyMA). The glass transition temperature was increased with the increase of UPyMA contents in PMMA copolymers due to strong self‐complementary multiple hydrogen bonding interactions of UPy moiety. The Fourier transform infrared and solid‐state NMR spectroscopic analyses provided positive evidence for the presence of multiple hydrogen bonds interaction of UPy moiety. Furthermore, the proton spin‐lattice relaxation time in the rotating frame [T_1ρ(H)] for the PMMA copolymers had a single value that was less than pure PMMA, indicating the smaller domain sizes in PMMA copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and gas permeability of ABA‐type triblock copolymers derived from fluorine‐containing polyimide with polyhedral oligomeric silsesquioxane

ABA‐type triblock copolymers derived from 4,4'‐(hexafluoroisopropylidene)diphthalicanhydride‐2,3,5,6‐tetramethyl‐1,4‐phenylenediamine (6FDA‐TeMPD) and methacryl phenyl polyhedral oligomeric silsesquioxane (MPPOSS) were synthesized by atom transfer radical polymerization. The chemical structure of the synthesized ABA‐type triblock copolymer was confirmed by ¹H NMR, ¹³C NMR, ²⁹Si NMR and Fourier transform infrared analyses. The ratios of 6FDA‐TeMPD and MPPOSS determined by TGA were 94/6, 85/15, 77/23, 68/32, 57/43 and 31/69. The film density of the ABA‐type triblock copolymer films did not conform to the mixing rule because of polyimide (PI) chain aggregation. Based on contact angle and water uptake analyses, the hydrophobicity of the ABA‐type triblock copolymer film was determined to be higher than the theoretical value because of POSS cage effects and PI chain aggregation. The gas permeability coefficient of the ABA‐type triblock copolymer decreased compared with that of PI because of aggregation of PI chains and inhibition of solubility decreases by substitutes with high affinity. ABA‐type triblock copolymer CO₂/H₂ separation performance increased compared with that of PI. The ABA‐type triblock copolymer derived from PI and MPPOSS can be described as a polymer material with higher hydrophobicity and higher CO₂/H₂ selectivity than PI. © 2015 Society of Chemical Industry     

Synthesis and properties of triblock copolymers containing PDMS via AGET ATRP

The bromo-terminated macroinitiator was prepared by direct addition reaction of difunctional poly(dimethylsiloxane) (PDMS) containing methyl methacrylate end groups with hydrobromic acid in acetic acid under mild conditions, and well-defined triblock copolymers of poly(methyl methacrylate-b-dimethylsiloxane-b-methyl methacrylate) (MMA-b-DMS-b-MMA) were synthesized via activators generated by election transfer atom transfer radical polymerization (AGET ATRP). The gel permeation chromatography data obtained verified the polymerization and showed the well controlling of the reaction. FTIR and ¹H NMR measured the structure of the macroinitiator and copolymers. The contact angle measurement indicated that the water contact angles decreased gradually with the increasing of PMMA block content. The self-assembly behaviors of the triblock polymer were studied by transmission electron micrograph, scanning electron microscopy, and dynamic light scattering measurement. The results indicated that the polymers could self-assemble into various complex morphologies in different solvents and the morphologies depended on the properties of solvents. The possible molecular packing models for self-assembly behaviors of the ABA triblock polymers were proposed.     

Synthesis and characterization of ABA triblock and novel multiblock copolymers from ethylene glycol,L‐lactide,and ϵ‐caprolactone

Three types of copolymers were synthesized and characterized. First, triblock ABA copolymers [where A is a homopolymer of ?‐caprolactone and B is poly(ethylene glycol)] were prepared by the ring‐opening polymerization of poly(ethylene glycol) with ?‐caprolactone in the presence of stannous octoate (Sn(Oct)₂). The spectral, thermal, and mechanical properties of one sample of these copolymers were studied, and it was discovered that these types of copolymers were more hydrophilic, possessed lower melting points, and had superior mechanical properties (greater toughness) than poly(?‐caprolactone). Second, triblock ABA copolymers [where A is a homopolymer of L ‐lactide and B is poly(ethylene glycol)] were prepared by the ring‐opening polymerization of poly(ethylene glycol) with L ‐lactide in the presence of Sn(Oct)₂. The mechanical properties of these copolymers were studied, and it was found that they were tougher and softer than poly(L ‐lactide). Third, novel ABA triblock copolymers [where A is a copolymer of ?‐caprolactone and L ‐lactide and B is poly(ethylene glycol)] were prepared, and ¹H‐NMR and ¹³C‐NMR spectra of these copolymers indicated a microblock structure for the two end blocks. The stress–strain behavior revealed low yields and high toughness for these copolymers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2072–2081, 2002     

Computer modeling study on the phase morphology of PS‐b‐PMMA copolymers

The phase morphologies of six kinds of designed poly(styrene‐block‐methyl methacrylate) copolymers were studied at 383, 413, and 443 K by mesoscopic modeling. The values of order parameter depended on both the structures of block copolymers and the simulation temperatures, whereas values of order parameter of the long chains were higher than those of the short ones; temperature showed a more obvious effect on long chains than on the short ones. These plain copolymers doped with PS or PMMA homopolymer showed different order parameter values. When the triblock copolymer was composed of the same component at both ends and was doped with a homopolymer with the same component as that in the middle of triblock copolymer, such as B6A3B6 doped with A3, B12A6B12 doped with A6, A6B12A6 doped with B12, and A3B6A3 doped with B6, it showed the highest order parameter values. The study of copolymers doped with nanoparticles showed that the mesoscopic phase was influenced by not only the properties of the nanoparticles, such as the size and density, but also the compositions of copolymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Thermal and optical properties of PMMA–titania hybrid materials prepared by sol‐gel approach with HEMA as coupling agent

A series of sol‐gel derived organic–inorganic hybrid materials consisting of organic poly(methyl methacrylate) (PMMA) and inorganic titania (TiO₂) were successfully synthesized by using 2‐hydroxyethyl methacrylate (HEMA) as coupling agent. In this work, HEMA is first copolymerized with methyl methacrylate monomer at specific feeding ratios by using benzoyl peroxide (BPO) as initiator. Subsequently, the as‐prepared copolymer (i.e., sol‐gel precursor) is then cohydrolyzed with various contents of titanium butoxide to afford chemical bondings to the forming titania networks to give a series of hybrid materials. Transparent organic–inorganic hybrid materials with different contents of titania are always achieved. Effects of the material composition on the thermal stability, optical properties, and morphology of neat copolymer and a series of hybrid materials, in the form of both coating and free‐standing film, are also studied by differential scanning calorimetry, thermogravimetric analysis, UV–Vis transmission spectra, refractometer, and atomic force microscopy, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 400–405, 2004