Poly(4‐acryloylmorpholine) oligomers carrying a β‐cyclodextrin residue at one terminus

A straightforward synthesis of amphiphilic β‐cyclodextrin‐poly(4‐acryloylmorpholine) (β‐CD‐PACM) polymers of controlled molecular weight, consisting of the radical polymerization of 4‐acryloylmorpholine in the presence of 6‐deoxy‐6‐mercapto‐β‐cyclodextrin (β‐CD‐SH) as chain‐transfer agent, has been established. These derivatives carry a single β‐cyclodextrin (β‐CD) moiety at one terminus and their average molecular weight is in the order of 10⁴. Thus, their β‐CD content is ～ 10% by weight. No evidence of un‐functionalized PACM was found in the final products. The chain‐transfer constant (C_T) of β‐CD‐SH was found to be 1.30 by independently determining the reaction constants of both chain‐transfer and propagation reactions. This ensures that the molecular weight, hence the β‐CD content of the polymers, does not significantly vary with conversion. These β‐CD‐PACM polymers are highly soluble in water as well as in several organic solvents such as chloroform and lower alcohols. They proved capable of solubilizing in water poorly soluble drugs such as 9‐[(2‐hydroxyethoxy)methyl]guanine (Acyclovir) and of gradually releasing them in aqueous systems. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1607–1617, 2008     

Mass spectrometry characterization of 3‐OH butyrated β‐cyclodextrin

Oligo(3‐OH butyrate)‐β‐cyclodextrin esters (PHB‐CD) were obtained through ring opening of β‐butyrolactone (β‐BL) in the presence of β‐cyclodextrin (CD) and (‐)‐sparteine (SP) as nucleophilic activator. The resulted reaction mixture was first separated in two fractions and then investigated through a deep mass spectrometry (MS) study performed on a liquid chromatography‐electrospray ionization‐quadrupole time of flight (LC‐ESI‐QTOF) instrument. LC MS and tandem MS structural assignment of the reaction products was completed by NMR. The performed analysis revealed that poly(3‐OH butyrate) homopolymers (PHB) are formed together with the PHB‐CD products. Secondary reactions resulting in the formation of crotonates were also proved to occur. A comparison between MS and NMR results demonstrated that more than one PHB oligomer is attached to the CD in the PHB‐CD product. The tandem MS fragmentation studies validated the proposed structure of CD derivatives. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Heat‐Induced Supramolecular Organogels Composed of α‐Cyclodextrin and “Jellyfish‐Like” β‐Cyclodextrin–Poly(ε‐caprolactone)

In general, the complexation and gelation behavior between biocompatible poly(ε‐caprolactone) (PCL) derivatives and α‐cyclodextrin (α‐CD) is extensively studied in water, but not in organic solvents. In this article, the complexation and gelation behavior between α‐CD and multi‐arm polymer β‐cyclodextrin‐PCL (β‐CD‐PCL) with a unique “jellyfish‐like” structure are thoroughly investigated in organic solvent N,N‐dimethylformamide and a new heat‐induced organogel is obtained. However, PCL linear polymers cannot form organogels under the same condition. The complexation is characterized by rheological measurements, DSC, XRD, and SEM. The SEM images reveal that the complexes between β‐CD‐PCL and α‐CD present a novel topological helix porous structure which is distinctly different from the lamellar structure formed by PCL linear polymers and α‐CD, suggesting the unique “jellyfish‐like” structure of β‐CD‐PCL is crucial for the formation of the organogels. This research may provide insight into constructing new supramolecular organogels and potential for designing new functional biomaterials. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1598–1606     

Three different β‐cyclodextrins direct the emulsion copolymerization of a highly fluorinated methacrylate toward distinctive nanostructured particle morphologies

Stable colloidal dispersions of nanostructured semifluorinated acrylic particles with an unfluorinated core and an outer layer consisting of copolymers of the highly hydrophobic and lipophobic heptadecafluorodecyl methacrylate (FMA) were successfully synthesized with the assistance of three different cyclodextrins as phase‐transfer catalysts: β‐cyclodextrin (β‐CD), hydroxypropyl β‐cyclodextrin (HpCD), and methyl β‐cyclodextrin (MeCD). While all the cyclodextrins form a stable inclusion complex (IC) with FMA, only the ICs with the more hydrophilic HpCD and MeCD are soluble in water. Nevertheless, incorporation of FMA in the particle shell copolymer could be achieved also when using β‐CD. On the other hand, the morphology of the nanostructured particles was characterized by a “patchy” fluorinated shell dependent on the cyclodextrin used, the best results being obtained with MeCD. A monomer‐starved semicontinuous emulsion polymerization procedure was essential to favor the CD‐mediated incorporation of FMA into the copolymer structure and to achieve a stable colloidal dispersion even in the presence of small amounts of mixed anionic–nonionic surfactants. The thermal and surface properties of the latex films showed a good correlation with the shell composition and patchy nanostructured morphology of the particles. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Electrically driven self‐healing polymers based on reversible guest–host complexation of β‐cyclodextrin and ferrocene

A multifunctional ferrocene‐modified poly(glycidyl methacrylate) (PGMA‐Fc) and a difunctional β‐cyclodextrin derivative (bis‐CD) has been prepared for the construction of an electrically driven removable and self‐healing polymeric materials based on the complexation reaction between ferrocene and β‐CD groups. The chemical structures of PGMA‐Fc and bis‐CD have been characterized with Fourier transform infrared, ¹H nuclear magnetic resonance, and X‐ray photoelectron spectroscopy. The effects of electrical voltages and medium conductivity on the decrosslinking efficiency of the crosslinked PGMA‐Fc/CD polymer have been examined. The PGMA‐Fc/CD network has shown removable feature and properties for application as a reworkable crosslinked material. Moreover, the crosslinked PGMA‐Fc/CD sample has shown electrically driven self‐healing behavior. The self‐healing performance could be enhanced with wetting the sample to increase the electrical conductivity. As a result, the material could serve as a self‐healing agent for commercial painting products. Preparation and application of a novel and efficient self‐healing polymer have been demonstrated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3395–3403     

pH‐ and β‐cyclodextrin‐responsive micelles based on polyaspartamide derivatives as drug carrier

A novel kind of graft polymer poly(aspartic acid)‐ethanediamine‐g‐adamantane/methyloxy polyethylene glycol (Pasp‐EDA‐g‐Ad/mPEG) was designed and synthesized for drug delivery in this study. The chemical structure of the prepared polymer was confirmed by proton NMR. The obtained polymer can self‐assemble into micelles which were stable under a physiological environment and displayed pH‐ and β‐cyclodextrin (β‐CD)‐responsive behaviors because of the acid‐labile benzoic imine linkage and hydrophobic adamantine groups in the side chains of the polymer. The doxorubicin (Dox)‐loaded micelles showed a slow release under physiological conditions and a rapid release after exposure to weakly acidic or β‐CD environment. The in vitro cytotoxicity results suggested that the polymer was good at biocompatibility and could remain Dox biologically active. Hence, the Pasp‐EDA‐g‐Ad/mPEG micelles may be applied as promising controlled drug delivery system for hydrophobic antitumor drugs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1387–1395     

Synthesis and self‐assembly behavior study of α,ω‐dicarboxyl‐poly(ethylene glycol)–permethyl‐6‐amino‐6‐deoxy‐β‐cyclodextrin‐monoamide: A new β‐cyclodextrin conjugate

A new type of amphiphilic macromolecule was synthesized through the attachment of a poly(ethylene glycol) chain to a permethyl‐amino‐β‐cyclodextrin ring. The structure of the product was studied with 1D and 2D NMR experiments and with MALDI‐TOF MS. The resulting comet‐shaped molecule showed self‐assembly behavior in polar solvents. The presence of supramolecular structures in aqueous media was detected with dynamic light scattering and proven also by 2D NOESY and DOSY experiments. The supramolecular structures that formed could serve as starting materials for new types of drug delivery bioconjugates containing two independent dopable sites, that is, the cyclodextrin ring and the core of the supramolecular structure. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5149–5155, 2007     

The study of enantioselectivity of all regioisomers of mono‐carboxymethyl‐β‐cyclodextrin used as chiral selectors in CE

This work documents the influence of the position of single carboxymethyl group on the β‐cyclodextrin skeleton on the enantioselectivity. These synthesized monosubstituted carboxymethyl cyclodextrin (CD) derivatives, native β‐cyclodextrin, and commercially available carboxymethyl‐β‐cyclodextrin with degree of substitution approximately 3 were used as additives into the BGE consisting of phosphate buffer at 20 mmol/L concentration, pH 2.5, and several biologically significant low‐molecular‐mass chiral compounds were enantioseparated by CE. The results indicate that different substituent location on β‐cyclodextrin skeleton has a significant influence on the enantioseparation of the investigated enantiomers. The enantioselectivity of 2^I‐O‐regioisomer was better than with native β‐cyclodextrin. Comparable results to native β‐cyclodextrin were obtained for 6^I‐O‐ regioisomer and the enantioselectivity of 3^I‐O‐regioisomer was even worse than with native β‐cyclodextrin. Commercially available derivative of CD provides better resolutions than the monosubstituted carboxymethyl CD derivatives for most of the investigated analytes.     

Polyrotaxanes based on polyethers and β‐cyclodextrin

A polyrotaxane in which β‐cyclodextrins (β‐CDs) are threaded onto a polyether chain was prepared by polycondensation of a β‐CD/bisphenol A (BPA) inclusion complex with aromatic dihalides. Two dihalides, with and without a side chain, were used. This polycondensation results in a polyrotaxane (or pseudopolyrotaxane for polymers without stoppers) with a 1:1 threading ratio when the side chain is present and 2:3 when there is none. The long side chain prevents dethreading of the macrocycles. The best yield and a good threading ratio were obtained when the polycondensation was performed by liquid?solid phase transfer catalysis without solvent (L/S PTC) using 2,5‐bi(iodomethyl)‐4‐methoxy‐(1‐octyloxy)benzene as dihalide. The ¹H NMR and FTIR spectra show that the products consist of β‐CD and polyether. The 2D NOESY NMR spectrum shows that the polyether chains are included in the β‐CD cavity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4391–4399, 2009     

Design and proof of reversible micelle‐to‐vesicle multistimuli‐responsive morphological regulations

Multistimuli‐responsive precise morphological control over self‐assembled polymers is of great importance for applications in nanoscience as drug delivery system. A novel pH, photoresponsive, and cyclodextrin‐responsive block copolymer were developed to investigate the reversible morphological transition from micelles to vesicles. The azobenzene‐containing block copolymer poly(ethylene oxide)‐b‐poly(2‐(diethylamino)ethyl methacrylate‐co‐6‐(4‐phenylazo phenoxy)hexyl methacrylate) [PEO‐b‐P(DEAEMA‐co‐PPHMA)] was synthesized by atom transfer radical polymerization. This system can self‐assemble into vesicles in aqueous solution at pH 8. On adjusting the solution pH to 3, there was a transition from vesicles to micelles. The same behavior, that is, transition from vesicles to micelles was also realizable on addition of β‐cyclodextrin (β‐CD) to the PEO‐b‐P(DEAEMA‐co‐PPHMA) solution at pH 8. Furthermore, after β‐CD was added, alternating irradiation of the solution with UV and visible light can also induce the reversible micelle‐to‐vesicle transition because of the photoinduced trans‐to‐cis isomerization of azobenzene units. The multistimuli‐responsive precise morphological changes were studied by laser light scattering, transmission electron microscopy, and UV–vis spectra. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Asymmetric cyclopolymerization of N‐tert‐butyl‐N‐allylacrylamide in the presence of β‐cyclodextrin

The radical polymerization of N‐tert‐butyl‐N‐allylacrylamide (t‐BAA) was carried out in a dimethyl sulfoxide/H₂O mixture in the presence of β‐cyclodextrin (β‐CD). The polymerization proceeded with the complete cyclization of the t‐BAA unit and yielded optically active poly(t‐BAA). The IR spectrum of the obtained polymer showed that the cyclic structure in the polymer was a five‐membered ring. The optical activity of poly(t‐BAA) increased with an increasing molar ratio of β‐CD to the t‐BAA monomer. The interaction of β‐CD with t‐BAA was confirmed by ¹H NMR and ¹³C NMR analyses of the polymerization system. It is suggested that interaction of the t‐BAA monomer with the hydrophobic cavity of β‐CD plays an important role in the asymmetric cyclopolymerization of t‐BAA. The radical copolymerization of t‐BAA with styrene (St), methyl methacrylate, ethyl methacrylate, or benzyl methacrylate (BMA) also produced optically active copolymers with a cyclic structure from the t‐BAA unit. St and BMA carrying a phenyl group were predicted to compete with t‐BAA for interaction with β‐CD in the copolymerization system. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2098–2105, 2000     

NMR spectra and structures of oridonin derivatives complexes with β‐cyclodextrin

Complexations between three oridonin derivatives and β‐cyclodextrin (βCD) were studied by nuclear magnetic resonance (NMR) method. Job's plots for complexes were depicted by ¹H NMR spectra chemical shifts, which proved the 1:1 stoichiometry inclusion complex formation between each derivative and βCD. Two‐dimensional rotating frame overhauser effect spectroscopy (2D ROESY) support the above conclusion and also proved that ring A of each oridonin derivative deeply enters into hydrophobic cavity from the wider rim and the other parts are outside the cavity. Apparent formation constants (K_a) of complexes between three oridonin derivatives and two CDs are calculated according to Scott's equation. Copyright © 2011 John Wiley & Sons, Ltd.     

Noncovalently connected micelles based on a β‐cyclodextrin‐containing polymer and adamantane end‐capped poly(ε‐caprolactone) via host–guest interactions

New random copolymers, poly(N‐vinyl‐2‐pyrrolidone‐co‐mono‐6‐deoxy‐6‐methacrylate ethylamino‐β‐cyclodextrin) (PnvpCD) bearing pendent β‐cyclodextrin (CD) groups were synthesized. PnvpCD formed soluble graft‐like polymer complex with adamantane (AD) end‐capped poly(ε‐caprolactone) (PclAD) in their common solvent N‐methyl‐2‐pyrrolidone driven by the inclusion interactions between the CD and AD groups. The formation of the graft complex has been confirmed by viscometry, dynamic light scattering (DLS), and isothermal titration calorimeter. The graft complex self‐assembled further into noncovalently connected micelles in water, which is a selective solvent for the main chain PnvpCD. Transmission electron microscopy, DLS, and atomic force microscopy have been used to investigate the structure and morphology of the resultant micelles. A unique “multicore” structure of the micelles, in which small PclAD domains scattered within the micelles, was obtained under nonequilibrium conditions in the preparation. However, the micelles prepared in a condition close to equilibrium possess an ordinary core‐shell structure. In both cases, the core and shell are believed to be connected by the AD‐CD inclusion complexation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4267–4278, 2009     

Synthesis of well‐defined 7‐arm and 21‐arm poly(N‐isopropylacrylamide) star polymers with β‐cyclodextrin cores via click chemistry and their thermal phase transition behavior in aqueous solution

The syntheses of well‐defined 7‐arm and 21‐arm poly(N‐isopropylacrylamide) (PNIPAM) star polymers possessing β‐cyclodextrin (β‐CD) cores were achieved via the combination of atom transfer radical polymerization (ATRP) and click reactions. Heptakis(6‐deoxy‐6‐azido)‐β‐cyclodextrin and heptakis[2,3,6‐tri‐O‐(2‐azidopropionyl)]‐β‐cyclodextrin, β‐CD‐(N₃)₇ and β‐CD‐(N₃)₂₁, precursors were prepared and thoroughly characterized by nuclear magnetic resonance and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. A series of alkynyl terminally functionalized PNIPAM (alkyne‐PNIPAM) linear precursors with varying degrees of polymerization (DP) were synthesized via atom transfer radical polymerization (ATRP) of N‐isopropylacrylamide using propargyl 2‐chloropropionate as the initiator. The subsequent click reactions of alkyne‐PNIPAM with β‐CD‐(N₃)₇ and β‐CD‐(N₃)₂₁ led to the facile preparation of well‐defined 7‐arm and 21‐arm star polymers, namely β‐CD‐(PNIPAM)₇ and β‐CD‐(PNIPAM)₂₁. The thermal phase transition behavior of 7‐arm and 21‐arm star polymers with varying molecular weights were examined by temperature‐dependent turbidity and micro‐differential scanning calorimetry, and the results were compared to those of linear PNIPAM precursors. The anchoring of PNIPAM chain terminal to β‐CD cores and high local chain density for star polymers contributed to their considerably lower critical phase separation temperatures (T_c) and enthalpy changes during phase transition as compared with that of linear precursors. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 404–419, 2009     

An H‐shaped polymer bonding β‐cyclodextrin at branch points: Synthesis and influences of attached β‐cyclodextrins on physical properties

We report on the synthesis of an H‐shaped polymer bonding β‐cyclodextrin (β‐CD) at branch points and influences of attached β‐CD on physical properties. First, a poly(ethylene glycol)(PEG)‐based functional macroinitiator bearing two azidos and four chlorines at chain‐ends (PEG‐2N₃(‐4Cl)) was prepared via terminal modification reactions. Then, PEG‐2N₃(‐4Cl) was applied to initiate the atom transfer radical polymerization of N‐isopropylacrylamide, leading to the synthesis of an H‐shaped block polymer with PEG as the central chain and poly(N‐isopropylacrylamide) (PNIPAM) as side‐arms (PEG‐2N₃(‐4PNIPAM)). Azido groups were at the branch points of the polymer. Finally, the click reaction between PEG‐2N₃(‐4PNIPAM) and alkynyl monosubstituted β‐cyclodextrin (β‐CD) afforded another H‐shaped polymer with two β‐CDs bonding at the polymer branch points (PEG‐2CD(‐4PNIPAM)). The glass transition temperature (T_g) and lower critical solution temperature (LCST) of the H‐shaped polymer increased after the attachment of β‐CD. The self‐assembly and thermal responsive behaviors, as well as the encapsulation behaviors of PEG‐2CD(‐4PNIPAM) were also altered. When temperature was below the LCSTs, PEG‐2N₃(‐2PNIPAM) dissolved in water molecularly, whereas PEG‐2CD(‐4PNIPAM) could self‐assemble into nano‐sized micelles. After the LCST transitions, PEG‐2N₃(‐4PNIPAM) aggregated into micron‐sized unstable particles, whereas PEG‐2CD(‐4PNIPAM) transformed into PNIPAM‐cored nanomicelles. Besides, PEG‐2CD(‐4PNIPAM) can encapsulate doxorubicin below its LCST due to the formation of micelles. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Cyclodextrin‐overhanging hyperbranched core‐double‐shell miktoarm architectures: Synthesis and gradient stimuli‐responsive properties

We report the synthesis and gradient stimuli‐responsive properties of cyclodextrin‐overhanging hyperbranched core‐double‐shell miktoarm architectures. A ionic hyperbranched poly(β‐cyclodextrin) (β‐CD) core was firstly synthesized via a convenient “A₂+B₃” approach. Double‐layered shell architectures, composed of poly(N‐isopropyl acrylamide) (PNIPAm) and poly(N,N‐dimethylaminoethyl methacrylate) (PDMAEMA) miktoarms as the outermost shell linked to poly(N,N‐diethylaminoethyl methacrylate) (PDEAEMA) homoarms which form the inner shell, were obtained by a sequential atom transfer radical polymerization (ATRP) and parallel click chemistry from the modified hyperbranched poly(β‐CD) macroinitiator. The combined characterization by ¹H NMR, ¹³C NMR, ¹H‐²⁹Si heteronuclear multiple‐bond correlation (HMBC), FTIR and size exclusion chromatography/multiangle laser light scattering (SEC/MALLS) confirms the remarkable hyperbranched poly(β‐CD) core and double‐shell miktoarm architectures. The gradient triple‐stimuli‐responsive properties of hyperbranched core‐double‐shell miktoarm architectures and the corresponding mechanisms were investigated by UV–vis spectrophotometer and dynamic light scattering (DLS). Results show that this polymer possesses three‐stage phase transition behaviors. The first‐stage phase transition comes from the deprotonation of PDEAEMA segments at pH 9–10 aqueous solution under room temperature. The confined coil‐globule conformation transition of PNIPAm and PDMAEMA arms gives rise to the second‐stage hysteretic cophase transition between 38 and 44 °C at pH 10. The third‐stage phase transition occurs above 44 °C at pH = 10 attributed to the confined secondary conformation transition of partial PDMAEMA segments. This cyclodextrin‐overhanging hyperbranched core‐double‐shell miktoarm architectures are expected to solve the problems of inadequate functionalities from core layer and lacking multiresponsiveness for shell layers existing in the dendritic core‐multishell architectures. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Highly enhanced phototoxicity of chlorin e6‐conjugated poly(β‐cyclodextrin) with gas forming capacity at an acidic tumor extracellular pH and its in vitro evaluation

In this study, we report a novel polysaccharidic drug conjugate consisting of poly(β‐cyclodextrin) [poly(β‐CD)] with gas‐forming carbonate linkages resulting from the chemical coupling of the hydroxyl groups of poly(β‐CD) and cholesteryl chloroformate (CC) and a photosensitizing drug (chlorin e6: Ce6). This drug conjugate was self‐assembled in aqueous solution leading to the production of nanoparticles containing the poly(β‐CD) on the hydrophilic outer shell and CC and Ce6 in the hydrophobic inner core. Cleavage (i.e. the detachment of CC moieties) of the carbonate linkage at a slightly acidic pH (~pH 6.5) produced carbon dioxide bubbles. More specifically, the nanoparticles (with autoquenched Ce6 molecules in their core at pH 7.4) were destabilized at pH 6.5, thereby dequenching the Ce6 molecules. These experimental results demonstrate that under light illumination the nanoparticles increased singlet oxygen generation at pH 6.5 compared to pH 7.4 and exhibited a higher phototoxicity for KB tumor cells at pH 6.5 compared to pH 7.4. This approach represents an effective photodynamic therapy for acidic tumors. Copyright © 2015 John Wiley & Sons, Ltd.     

Preparation and characterization of poly(ethylene oxide)‐loaded hydroxypropyl‐β‐cyclodextrin nanofibers

Hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) is a modified β‐cyclodextrin (β‐CD) derivative, which is toxicologically harmless to mammals and other animals. HP‐β‐CD is electrospun from an aqueous solution by blending with a non‐toxic, biocompatible, synthetic polymer poly(ethylene oxide) (PEO). Aqueous solutions containing different HP‐β‐CD/PEO blends (50:50–80:20) with variable concentrations (4 wt%–12 wt%) were used. Scanning electron microscope was used to investigate the morphology of the fibers, and Fourier transform infrared spectroscopy analysis confirmed the presence of HP‐β‐CD in the fiber. Uniform nanofibers with an average diameter of 264, 244, and 236 nm were obtained from 8 wt% solution of 50:50, 60:40, and 70:30 HP‐β‐CD/PEO, respectively. The average diameter of the fiber was decreased with increasing of HP‐β‐CD/PEO ratio. However, a higher proportion of HP‐β‐CD in the spinning solution increased beads in the fibers. The polymer concentration had no significant effect on the fiber diameter. The most uniform fibers with the narrowest diameter distribution were obtained from the 8 wt% of 50:50 solution. Copyright © 2015 John Wiley & Sons, Ltd.     

Photoreactive nanomatrix structure formed by graft‐copolymerization of 1,9‐nonandiol dimethacrylate onto natural rubber

Formation of photoreactive nanomatrix structure was investigated by graft‐copolymerization of an inclusion complex of 1,9‐nonandiol dimethacrylate (NDMA) with β‐cyclodextrin (β‐CD) onto natural rubber particle using potassium persulfate (KPS), tert‐butyl hydroperoxide/tetraethylenepentamine (TBHPO/TEPA), cumene hydroperoxide/tetraethylenepentamine (CHPO/TEPA), and benzoyl peroxide (BPO) as an initiator. The graft copolymer was characterized by ¹H NMR and FTIR after coagulation. The conversion of NDMA and the amount of residual methacryloyl group were found to be 58.5 w/w % and 1.81 w/w %, respectively, under the suitable condition of the graft‐copolymerization. The morphology of the film specimen, prepared from the graft copolymer, was observed by transmission electron microscopy (TEM) after staining the film with OsO₄. Natural rubber particle of about 1.0 μm in diameter was dispersed in poly(NDMA) matrix of about 10 nm in thickness. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2418–2424, 2010