Supramolecular inclusion complexes of star‐shaped poly(ε‐caprolactone) with α‐cyclodextrin

Both star‐shaped poly(ε‐caprolactone) (PCL) having 4 arms (4sPCL) and 6 arms (6sPCL) and linear PCL having 1 arm (LPCL) and 2 arms (2LPCL) were synthesized and then investigated for inclusion complexation with α‐cyclodextrin (α‐CD). The supramolecular inclusion complexes (ICs) were in detail characterized by ¹H NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X‐ray diffraction, solid‐state carbon nuclear magnetic resonance spectroscopy using cross‐polarization and magic‐angle spinning, and Fourier transform infrared, respectively. The stoichiometry (CL:CD, mol:mol) of all ICs increased with the increasing branch arm of PCL polymers, and it was in the order of α‐CD‐6sPCL1 ICs > α‐CD‐4sPCL ICs > α‐CD‐2LPCL ICs > α‐CD‐LPCL ICs. All analyses indicated that the branch arms of star‐shaped PCL polymers were included into the hydrophobic α‐CD cavities and their original crystalline properties were completely suppressed. Moreover, the ICs of star‐shaped PCL with α‐CD had a channel‐type crystalline structure similar to that formed between the linear PCL and α‐CD. Furthermore, the thermal stability of the free PCL polymers probably controlled that of the guest polymers included in the ICs. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4721–4730, 2005     

Preparation of inclusion complex between polyaniline and β‐cyclodextrin in aqueous solution

Two routes have been developed inorder to prepare an inclusion complex of polyaniline (PANI) and β‐cyclodextrin (βCyD). The first route was to in situ polymerize N‐phenyl‐1,4‐phenylenediamine (PPD) which was encapsulated in βCyD in advance. The formation of an inclusion complex was confirmed by UV‐vis, circular dichroism (CD), and NMR spectra. It was found that the synthesized complex was readily dissolved in a range of solvents due to the solubility of βCyD. In these solvents, PANI was well encapsulated by βCyD with some conformation change in the chain of PANI, which was proved by the CD spectra of PANI. The second route involved preparing the inclusion complex by post‐encapsulation of PANI emeraldine base (EB) into βCyD in aqueous solution at room temperature. The encapsulation of EB into βCyD was confirmed by FT‐IR and UV‐vis spectra. The band shift in UV‐vis spectra indicated that the inclusion complexation was a gradual process, and the change in the chain conformation of PANI was also observed after it was encapsulated into βCyD. Copyright © 2003 John Wiley & Sons, Ltd.     

Supramolecular inclusion complexes of a star polymer containing cholesterol end‐capped poly(ε‐caprolactone) arms with β‐cyclodextrin

A novel hexa‐armed and star‐shaped polymer containing cholesterol end‐capped poly(ε‐caprolactone) arms emanating from a phosphazene core (N₃P₃‐(PCL‐Chol)₆) was synthesized by a combination of ring‐opening polymerization and “click” chemistry techniques. For this purpose, the terminal ? OH groups of the synthesized precursor (N₃P₃‐(PCL‐OH)₆) were converted into –Chol through a series of reaction. Both N₃P₃‐(PCL‐OH)₆ and N₃P₃‐(PCL‐Chol)₆ were then employed in the preparation of supramolecular inclusion complexes (ICs) with β‐cyclodextrin (β‐CD). The latter formed ICs with β‐CD in higher yield. The host–guest stoichiometry (ε‐CL:β‐CD, mol:mol) in the ICs of N₃P₃‐(PCL‐Chol)₆ was found to be 1.2. The formation of supramolecular ICs of N₃P₃‐(PCL‐Chol)₆ with β‐CD was confirmed by using Fourier transform infrared (FTIR) and ¹H nuclear magnetic resonance (NMR) spectroscopic methods, wide‐angle X‐ray diffraction (WAXD), and thermal analysis techniques. WAXD data showed that the obtained ICs with N₃P₃‐(PCL‐Chol)₆ had a channel‐type crystalline structure, indicating the suppression of the original crystallization of N₃P₃‐(PCL‐Chol)₆ in β‐CD cavities. Moreover, the thermal stabilities of ICs were found to be higher than those of the free star polymer and β‐CD. Furthermore, the surface properties of N₃P₃‐(PCL‐Chol)₆ and its ICs with β‐CD were investigated by static contact angle measurements. The obtained results proved that the wettability of N₃P₃‐(PCL‐Chol)₆ successfully increased with the formation of its ICs with β‐CD. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3406–3420     

Poly(ethylene imine)‐graft‐poly(ethylene oxide) brush‐like copolymers: Preparation,thermal properties,and selective supramolecular inclusion complexation with α‐cyclodextrin

Poly(ethylene imine)‐graft‐poly(ethylene oxide) (PEI‐g‐PEO) copolymers were synthesized via Michael addition reaction between acryl‐terminated poly(ethylene oxide) methyl ether (PEO) and poly(ethylene imine) (PEI). The brush‐like copolymers were characterized by means of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. It is found that the crystallinity of the PEO side chains in the copolymers remained unaffected by the PEI backbone whereas the crystal structure of PEO side chains was altered to some extent by the PEI backbone. The crystallization behavior of PEO blocks in the copolymers suggests that the bush‐shaped copolymers are microphase‐separated in the molten state. The PEO side chains of the copolymers were selectively complexed with α‐cyclodextrin (α‐CD) to afford hydrophobic side chains (i.e., PEO/α‐CD inclusion complexes). The X‐ray diffraction (XRD) shows that the inclusion complexes (ICs) of the PEO side chains displayed a channel‐type crystalline structure. It is identified that the stoichiometry of the inclusion complexation of the PEI‐g‐PEO with α‐CD is close to that of the control PEO with α‐CD. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2296–2306, 2008     

Supramolecular inclusion complexation of polyhedral oligomeric silsesquioxane capped poly(ε‐caprolactone) with α‐cyclodextrin

Supramolecular inclusion complexes (ICs) involving polyhedral oligomeric silsesquioxane (POSS) capped poly(?‐caprolactone) (PCL) and α‐cyclodextrin (α‐CD) were investigated. POSS‐terminated PCLs with various molecular weights were prepared via the ring‐opening polymerization of ?‐caprolactone (CL) with 3‐hydroxypropylheptaphenyl POSS as an initiator. Because of the presence of the bulky silsesquioxane terminal group, the inclusion complexation between α‐CD and the POSS‐capped PCL was carried out only with a single end of a PCL chain threading inside the cavity of α‐CD, which allowed the evaluation of the effect of the POSS terminal groups on the efficiency of the inclusion complexation. The X‐ray diffraction results indicated that the organic–inorganic ICs had a channel‐type crystalline structure. The stoichiometry of the organic–inorganic ICs was quite dependent on the molecular weights of the POSS‐capped PCLs. With moderate molecular weights of the POSS‐capped PCLs (e.g., M_n =3860 or 9880), the stoichiometry was 1:1 mol/mol (CL unit/α‐CD), which was close to the literature value based on the inclusion complexation of α‐CD with normal linear PCL chains with comparable molecular weights. When the PCL chains were shorter (e.g., for the POSS‐capped PCL of M_n = 1720 or 2490), the efficiency of the inclusion complexation decreased. The decreased efficiency of the inclusion complexation could be attributed to the lower mobility of the bulky POSS group, which restricted the motion of the PCL chain attached to the silsesquioxane cage. This effect was pronounced with the decreasing length of the PCL chains. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1247–1259, 2007     

Dual‐responsive supramolecular inclusion complexes of block copolymer poly(ethylene glycol)‐block‐poly[(2‐dimethylamino)ethyl methacrylate] with α‐cyclodextrin

A new class of temperature and pH dual‐responsive and injectable supramolecular hydrogel was developed, which was formed from block copolymer poly(ethylene glycol)‐block‐poly[(2‐dimethylamino)ethyl methacrylate] (PEG‐b‐PDMAEMA) and α‐cyclodextrin (α‐CD) inclusion complexes (ICs). The PEG‐b‐PDMAEMA diblock copolymers with different ratio of ethylene glycol (EG) to (2‐dimethylamino)ethyl methacrylate (DMAEMA) (102:46 and 102:96, respectively) were prepared by atom transfer radical polymerization (ATRP). ¹H NMR measurement indicated that the ratio of EG unit to α‐CD in the resulted ICs was higher than 2:1. Thermal analysis showed that thermal stability of ICs was improved. The rheology studies showed that the hydrogels were temperature and pH sensitive. Moreover, the hydrogels were thixotropic and reversible. The self‐assembly morphologies of the ICs in different pH and ionic strength environment were studied by transmission electron microscopy. The formed biocompatible micelles have potential applications as biomedical and stimulus‐responsive material. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2143–2153, 2010     

POSS end‐linked peptide‐functionalized poly(ɛ‐caprolactone)s and their inclusion complexes with α‐cyclodextrin

In this report, we have synthesized organic/inorganic hybrid peptide–poly(?‐caprolactone) (PCL) conjugates via ring opening polymerization (ROP) of ?‐caprolactone (CL) in the presence of two sequence defined peptide initiators, namely POSS‐Leu‐Aib‐Leu‐NH₂ (POSS: polyhedral oligomeric silsesquioxane; Leu: Leucine; Aib: α‐aminoisobutyric acid) and OMe‐Leu‐Aib‐Leu‐NH₂. Covalent attachment of peptide segments with the PCLs were examined by ¹H and ²⁹Si NMR spectroscopy, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) and FTIR spectroscopy. Supramolecular inclusion complexations of synthesized peptide‐PCL conjugates with α‐cyclodextrin (α‐CyD) were studied to understand the effect of POSS/OMe‐peptide moieties at the PCL chain ends. Inclusion complexation of peptide‐PCL conjugates with α‐CyD produced linear polypseudorotaxane, confirmed by ¹H NMR, FTIR, powder X‐ray diffraction (PXRD), polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Extent of α‐CyD threading onto the hybrid peptide‐PCL conjugated polymers is less than that of α‐CyD threaded onto the linear PCL. Thus, PCL chains were not fully covered by the host α‐CyD molecules due to the bulky POSS/OMe‐peptide moieties connected with the one edge of the PCL chains. PXRD experiment reveals channel like structures by the synthesized inclusion complexes (ICs). Spherulitic morphologies of POSS/OMe‐peptide‐PCL conjugates were fully destroyed after inclusion complexation with α‐CyD and tiny nanoobjects were produced. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3643–3651.     

Complexation of dodecyl‐substituted poly(acrylate) by linked β‐cyclodextrin dimers and trimers in aqueous solution

Two‐dimensional NOESY ¹H NMR, isothermal titration calorimetric (ITC), and rheological studies of host–guest complexation by β‐cyclodextrin, β‐CD, and the β‐CD groups of the linked β‐CD dimers, β‐CD₂ur and β‐CD₂su and trimers, β‐CD₃bz and β‐CDen₃bz, of the dodecyl, C12, substituents of the 3.0% substituted poly(acrylate), PAAC12, in aqueous solution are reported. Complexations by β‐CD, β‐CD₂ur, β‐CD₂su, β‐CD₃bz, and β‐CDen₃bz of the C12 substituents of PAAC12 in 0.2 wt % solution exhibit complexation constants 10^?4K₁₁ (298.2 K) = 0.83, 5.80, 4.40, 15.0, and 1.50 dm³ mol^?1, respectively. (The corresponding ΔH₁₁ and TΔS₁₁ show a linear relationship.) The rheologically determined zero‐shear viscosities of 3.3 wt % aqueous solutions of PAAC12 alone and in the presence of β‐CD, β‐CD₂ur, β‐CD₂su, β‐CD₃bz, and β‐CDen₃bz (where the β‐CD groups and C12 substituents are equimolar) are 0.016, 0.03, 0.12, 0.25, 0.12, and 0.08 Pa s (298.2 K), respectively, and show PAAC12 to form interstrand cross‐links through complexation. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1278–1286     

Supramolecular micellization and pH‐inducible gelation of a hydrophilic block copolymer by block‐specific threading of α‐cyclodextrin

A poly(ethylene glycol)‐b‐poly(L ‐lysine) diblock copolymer (PEG‐b‐PLL) was synthesized. Micellization of this hydrophilic copolymer due to the block‐specific threading of α‐cyclodextrin (α‐CD) molecules onto the polyethylene glycol (PEG) block yielded supramolecular‐structured nanoparticles, which undergoes pH‐inducible gelation in aqueous media. The pH‐inducible gelation of supramolecular micelle in water appeared to be completely reversible upon pH changes. The synergetic effect of selective complexation between PEG block and α‐CD and the pH‐inducible hydrophobic interaction between PLL blocks at pH 10 was believed to be the driving force for the formation of the supramolecular hydrogel. ¹H NMR and wide angle X‐ray diffraction (WAXD) were employed to confirm the inclusion complexation between α‐CD and PEG block. Meanwhile, the morphology of the micellized nanoparticles was investigated by transmission electron microscopy (TEM). The thermal stability of inclusion complexes (ICs) was investigated and the rheologic experiment was conducted to reveal the micelle‐gel transition. Such pH‐induced reversible micelle‐gel transition of the supramolecular aggregates may find applications in several fields, for example as advanced biomedical material possessing stimulus‐responsiveness. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 782–790, 2008     

Preparation of novel poly(ethylene oxide‐co‐glycidol)‐graft‐poly(ε‐caprolactone) copolymers and inclusion complexation of the grafted chains with α‐cyclodextrin

A well‐defined comblike copolymer of poly(ethylene oxide‐co‐glycidol) [(poly(EO‐co‐Gly)] as the main chain and poly(ε‐caprolactone) (PCL) as the side chain was successfully prepared by the combination of anionic polymerization and ring‐opening polymerization. The glycidol was protected by ethyl vinyl ether to form 2,3‐epoxypropyl‐1‐ethoxyethyl ether (EPEE) first, and then ethylene oxide was copolymerized with EPEE by an anionic mechanism. The EPEE segments of the copolymer were deprotected by formic acid, and the glycidol segments of the copolymers were recovered after saponification. Poly(EO‐co‐Gly) with multihydroxyls was used further to initiate the ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate. When the grafted copolymer was mixed with α‐cyclodextrin, crystalline inclusion complexes (ICs) were formed, and the intermediate and final products, poly(ethylene oxide‐co‐glycidol)‐graft‐poly(ε‐caprolactone) and ICs, were characterized with gel permeation chromatography, NMR, differential scanning calorimetry, X‐ray diffraction, and thermogravimetric analysis in detail. The obtained ICs had a channel‐type crystalline structure, and the ratio of ε‐caprolactone units to α‐cyclodextrin for the ICs was higher than 1:1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3684–3691, 2006     

Inclusion complexes of α‐cyclodextrin and (AB)n block copolymers

Cyclodextrins thread onto polymer chains to form inclusion complexes, especially when the polymer is hydrophobic relative to the solvent. Selective threading might occur when the polymer architecture contains both hydrophobic and hydrophilic segments. α‐Cyclodextrin formed crystalline inclusion complexes with (AB)_n microblock copolymers, where the A block was a linear alkyl segment containing a single double bond and the B block was an exact length segment of poly(ethylene oxide). The complexes were isolated and characterized by solution and solid‐state NMR, X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. Each method confirmed complex formation and showed that the physical properties of the complexes were distinct from those of its individual components. The X‐ray data were consistent with known inclusion complexes having a channel or column crystal structure. The stoichiometry of the complex formation, 2.3 α‐cyclodextrin rings per polymer repeat unit, was determined by NMR analysis of the complexes and from an analysis of the inclusion complex yields. The data suggest that the inclusion complex stoichiometry is defined by the increasing insolubility of the polymer–cyclodextrin complex. Solid‐state NMR data were consistent with a preference for threading onto hydrophobic segments of the (AB)_n polymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2731–2739, 2001     

Microwave‐assisted synthesis of star‐shaped poly(ε‐caprolactone)‐block‐poly(L‐lactide) copolymers and the crystalline morphologies

A monomode microwave reactor was used for the synthesis of designed star‐shaped polymers, which were based on dipentaerythritol with six crystallizable arms of poly(ε‐caprolactone)‐b‐poly(L ‐lactide) (PCL‐b‐PLLA) copolymer via a two‐step ring‐opening polymerization (ROP). The effects of irradiation conditions on the molecular weight were studied. Microwave heating accelerated the ROP of CL and LLA, compared with the conventional heating method. The resultant hexa‐armed polymers were fully characterized by means of FTIR, ¹H NMR spectrum, and GPC. The investigation of thermal properties and crystalline behaviors indicated that the crystalline behaviors of polymers were largely depended on the macromolecular architecture and the length of the block chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Organic–inorganic hybrid brushes consisting of macrocyclic oligomeric silsesquioxane and poly(ε‐caprolactone): Synthesis,characterization, and supramolecular inclusion complexation with α‐cyclodextrin

Organic–inorganic hybrid brushes comprised of macrocyclic oligomeric silsesquioxane (MOSS) and poly(ε‐caprolactone) (PCL) were synthesized via the ring‐opening polymerization of ε‐caprolactone (CL) with cis‐hexa[(phenyl) (2‐hydroxyethylthioethyldimethylsiloxy)]cyclohexasiloxane as the initiator. The MOSS macromer bearing hydroxyl groups was synthesized via the thiol‐ene radical addition reaction between cis‐hexa[(phenyl)(vinyldimethylsiloxy)]cyclohexasiloxane and β‐mercaptoethanol. The organic–inorganic PCL cyclic brushes were characterized by means of nuclear magnetic resonance spectroscopy (NMR) and gel permeation chromatography (GPC). These MOSS–PCL brushes were then used to prepare the supramolecular inclusion complexes with α‐cyclodextrin (α‐CD). The X‐ray diffraction (XRD) indicates that the organic–inorganic inclusion complexes (ICs) have a channel‐type crystalline structure. It is noted that the molar ratios of CL unit to α‐CD for the organic–inorganic ICs are quite dependent on the lengths of the PCL chains bonded to the silsesquioxane macrocycle. While the PCL chains were short, the efficiency of inclusion complexation was significantly decreased. The decreased efficiency could be attributed to the repulsion of the adjacent PCL chains bonded to the silsesquioxane macrocycle and the restriction of the bulky silsesquioxane macrocycle on the motion of PCL chains; this effect is pronounced with decreasing the length of the PCL chains. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009     

Amphiphilic β‐cyclodextrin‐based star‐like block copolymer unimolecular micelles for facile in situ preparation of gold nanoparticles

Multifunctional polymer unimolecular micelles, which are used as templates to fabricate stable gold nanoparticles (GNPs) in one‐step without external reductant, have been designed and prepared. Amphiphilic 21‐arm star‐like block copolymers β‐cyclodextrin‐{poly(lactide)‐poly(2‐(dimethylamino) ethyl methacrylate)‐poly[oligo(2‐ethyl‐2‐oxazoline)methacrylate]}₂₁ [β‐CD‐(PLA‐PDMAEMA‐PEtOxMA)₂₁] and the precursors are synthesized by the combination of ring‐opening polymerization (ROP) and activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The tertiary amine groups of PDMAEMA block reduce the counterion to zerovalent gold in situ, and these gold atoms combine mutually to form final GNPs. GNPs with relatively small size and narrow size distribution can be obtained in longer DMAEMA block copolymer, larger molar ratio of DMAEMA to HAuCl₄ and smaller absolute concentrations of both polymer and HAuCl₄. These results showed that the unimolecular micelles can be used as templates for preparing and stabilizing GNPs in situ without any external reducing agents and organic solvents, suggesting that the nanocomposite systems are latent nanocarriers for further biomedical application. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 186–196     

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     

Capillary electrophoretic separation and computational modeling of inclusion complexes of β‐cyclodextrin and 18‐crown‐6 ether with primaquine and quinocide

The antimalarial drug primaquine (PQ) and its contaminant, the positional isomer quinocide (QC) have been successfully separated using capillary electrophoresis with either β‐cyclodextrin (β‐CD) or 18‐crown‐6 ether (18C6) as chiral mobile phase additive. The interactions of the drugs with cyclodextrins and 18C6 were studied by the semiempirical method (Parametric Model 3) PM3. Theoretical calculations for the inclusion complexes of PQ and QC with α‐CD, β‐CD and 18C6 were performed. Data from the theoretical calculations are correlated and discussed with respect to the electrophoretic migration behavior. More stable complexes are predicted for the PQ–β‐CD and PQ–18C6 complexes. The coelution of PQ and QC when α‐CD was used as buffer additive can be explained by their comparable stabilities of the inclusion complex formed, while significant differences in the complexation stabilities of the drugs with β‐CD is responsible for their separation. The stronger hydrogen bonding in PQ–18C6 system is responsible for the separation between PQ and QC when 18C6 was used as chiral mobile phase additive. Copyright © 2009 John Wiley & Sons, Ltd.     

Poly(ε‐caprolactone)–poly(isobutylene): A crystallizing,hydrogen‐bonded pseudo‐block copolymer

The crystallization of block copolymers (BCPs) under homogeneous and heterogeneous nucleation is currently well understood revealing the strong interplay of crystallization in competition to microphase separation. This article reports investigations on synthesis and crystallization processes in weakly interacting supramolecular pseudo‐BCPs, composed of poly(ε‐caprolactone) (PCL) and poly(isobutylene) (PIB) blocks, connected by a specifically interacting hydrogen bond (thymine/2,6‐diaminotriazine). Starting from ring opening polymerization of ε‐caprolactone, the use of “click”‐chemistry enabled the introduction of thymine endgroups onto PCL polymer, thus generating the fully thymine‐substituted pure PCLs ( 1a , 1b ) as judged via NMR and MALDI analysis. Physical mixing of 1a , 1b with a bivalent, bis(2,6‐diaminotriazine)‐containing molecule ( 2 ) generated the bivalent polymers BC1 and BC2 , whereas mixing of 1a or 1b with the 2,6‐diaminotriazine‐substituted PIB ( 3 ) generated the supramolecular pseudo‐BCPs BC3 and BC4 . Thermal investigations (DSC, Avrami analysis) revealed only minor changes in the crystallization behavior of BC1 – BC4 with Avrami exponents close to three, indicative of a confluence of the growing crystals during the crystallization process. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

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 and Characterization of Star‐Shaped Diblock Poly(ε‐caprolactone)/Poly(ethylene oxide) Copolymers

Summary: Star‐shaped hydroxy‐terminated poly(ε‐caprolactone)s (ssPCL), with arms of different lengths, were obtained by ring‐opening polymerization (ROP) of ε‐caprolactone initiated by pentaerythritol, and were condensed with α‐methyl‐ω‐(3‐carboxypropionyloxy)‐poly(ethylene oxide)s ( = 550–5 000) to afford four‐armed PCL‐PEO star diblock copolymers (ssPCL‐PEO). The polymers were characterized by ¹H and ¹³C NMR spectroscopy and size‐exclusion chromatography (SEC). The melting behavior of ssPCLs was studied by differential scanning calorimetry (DSC). X‐ray diffraction and DSC techniques were used to investigate the crystalline phases of ssPCL‐PEOs.

The part of the synthesis of four‐armed star‐shaped diblock poly(ε‐caprolactone)‐poly(ethylene oxide) copolymers as described.     

Self‐assembling amphiphilic block copolymer from renewable δ‐decalactone and δ‐dodecalactone

Aliphatic polyesters have many applications in the biomedical field due to their properties and facile degradation. They are commonly synthesized via ring opening polymerization (ROP) with metal‐based catalysts, but as high temperatures are needed and the products contain metal, organocatalysts are now widely adopted to polymerize them at room temperature while also ensuring short reaction times. Here, 1,7,7‐triazabicyclo[4.4.0]‐dec‐5‐ene is used to polymerize less reactive but renewably‐derived lactones, namely δ‐decalactone and δ‐dodecalactone. These monomers were chosen in the attempt of creating renewable and highly lipophilic materials for drug delivery applications as alternatives to the more traditional, but non‐renewable δ‐valerolactone and ?‐caprolactone. A combination of ROP and living radical polymerization Reversible Addition‐Fragmentation Chain Transfer is proposed here to synthesize grafted block copolymers. They are able to self‐assemble in water, forming micelles where the lipophilic polyester core is able to entrap a lipophilic drug, thus making the system a good candidate for drug delivery. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 3788–3797