Cyclohexene oxide mid‐chain functional macromonomer of poly(ε‐caprolactone): Synthesis,characterization, and photoinitiated cationic homo‐ and copolymerization

In this study, a novel well‐defined epoxy mid‐chain functional macromonomer of poly(ε‐caprolactone) (PCL) has been synthesized by ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) and epoxidation on workup with 3‐chloroperoxybenzoic acid. The ROP of ε‐CL monomer in bulk at 110°C, by means of a dihydroxy functional initiator namely, 3‐cyclohexene‐1,1‐dimethanol in conjunction with stannous‐2‐ethylhexanoate, (Sn(Oct)₂), yielded a well‐defined PCL with a cyclohexene mid‐chain group. The epoxidation of the cyclohexene (CH) mid‐chain group of PCL was performed using 3‐chloroperoxybenzoic acid. GPC, IR, and ¹H‐NMR analyses revealed that a low‐polydispersity macromonomer of PCL with the desired cyclohexene oxide (CHO) functionality at the mid‐chain was obtained. The photoinduced cationic polymerizations of this macromonomer yielded comb‐shaped and graft copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis,characterization and biocompatibility of novel biodegradable poly[((R)‐3‐hydroxybutyrate)‐block‐(D,L‐lactide)‐block‐(ε‐caprolactone)] triblock copolymers

BACKGROUND: Biodegradable block copolymers have attracted particular attention in both fundamental and applied research because of their unique chain architecture, biodegradability and biocompatibility. Hence, biodegradable poly[((R )‐3 ‐hydroxybutyrate)‐block‐(D ,L ‐lactide)‐block‐(ε‐caprolactone)] (PHB‐PLA‐PCL) triblock copolymers were synthesized, characterized and evaluated for their biocompatibility. RESULTS: The results from nuclear magnetic resonance spectroscopy, gel permeation chromatography and thermogravimetric analysis showed that the novel triblock copolymers were successfully synthesized. Differential scanning calorimetry and wide‐angle X‐ray diffraction showed that the crystallinity of PHB in the copolymers decreased compared with methyl‐PHB (LMPHB) oligomer precursor. Blood compatibility experiments showed that the blood coagulation time became longer accompanied by a reduced number of platelets adhering to films of the copolymers with decreasing PHB content in the triblocks. Murine osteoblast MC3T3‐E1 cells cultured on the triblock copolymer films spread and proliferated significantly better compared with their growth on homopolymers of PHB, PLA and PCL, respectively. CONCLUSION: For the first time, PHB‐PLA‐PCL triblock copolymers were synthesized using low molecular weight LMPHB oligomer as the macroinitiator through ring‐opening polymerization with D ,L ‐lactide and ε‐caprolactone. The triblock copolymers exhibited flexible properties with good biocompatibility; they could be developed into promising biomedical materials for in vivo applications. Copyright © 2008 Society of Chemical Industry     

Synthesis and characterization of α‐butyl‐ω‐N,N‐dihydroxyethylaminopropylpolydimethylsiloxane

α‐Butyl‐ω‐N,N‐dihydroxyethylaminopropylpolydimethylsiloxane, a monotelechelic polydimethylsiloxane with a diol‐end group, which is used to prepare polyurethane–polysiloxane graft polymer, was successfully synthesized. The preparation included five steps, which are hydroxyl protection, alkylation, anionic ring‐opening polymerization, hydrosilylation, and deprotection. The products were characterized by FTIR, GC, LC‐MS, ¹H NMR, and elemental analysis. The results showed that each step was successfully carried out and the targeted products were synthesized in all cases. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis of ω‐pyrenyl‐functionalized poly(1,3‐cyclohexadiene)

ω‐Pyrenyl‐functionalized poly(1,3‐cyclohexadiene) (PCHD) was successfully synthesized by the postpolymerization reaction of poly(1,3‐cyclohexadienyl)lithium (PCHDLi) with 1‐chloromethylpyrene (ClMe‐PY). This postpolymerization reaction consisted of two competitive reactions: the addition reaction of the pyrenyl group, and a hydrogen abstraction reaction (lithiation) as a side reaction. The degree of nucleophilicity of PCHDLi was a very important factor for suppression of the side reaction, and the PCHDLi/amine system, which has high nucleophilicity, produced high ω‐pyrenyl‐functionalization for PCHD. The UV/vis and fluorescence spectra for ω‐pyrenyl‐functionalized PCHD were bathochromically shifted, relative to that of pyrene. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Curing reaction mechanism and heat resistance properties of hexa‐(4‐carboxyl‐phenoxy)‐cyclotriphosphazene/bisphenol A aniline benzoxazine blends

A blend system of hexa‐(4‐carboxyl‐phenoxy)‐cyclotriphosphazene (HCPCP) and bisphenol A aniline benzoxazine (BA‐a) was prepared, and its curing reaction mechanism and heat resistance properties were studied. The curing reaction mechanism of the blend was explored by differential scanning calorimetry, Fourier transform infrared spectroscopy, and modeling software using model compounds Ar‐COOH and hexachlorocyclotriphosphazene (HCCP). The heat resistance properties of the cured blends were studied by thermogravimetric analysis and dynamic mechanical analysis. The polymerization of benzoxazine was catalyzed by HCPCP through phosphazene ring and acid groups, and phosphazene played a predominant role. Compared with the materials with a single functional group (Ar‐COOH and HCCP), HCPCP containing two functional groups (phosphazene ring and acid) exhibited weaker catalytic effects, mainly due to the high molecular weight of HCPCP obstructing movement and causing steric hindrance. In addition, HCPCP had a positive effect on the thermal stability of polybenzoxazine from 250 to 400 °C. When the HCPCP content reached 3%, the cured blend had the highest glass‐transition temperature (222.2 °C), which is higher by 20 °C than that of cured benzoxazine. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46389.     

Volume‐expandable monomer 5,5‐dimethyl‐1,3‐dioxolan‐2‐one: Its copolymerization behavior with epoxide and its applications to shrinkage‐controlled epoxy‐curing systems

The copolymerization of epoxides and a six‐membered cyclic carbonate, 5,5‐dimethyl‐1,3‐dioxan‐2‐one (DM6CC), was carried out with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene as an initiator. In the copolymerization of glycidyl phenyl ether (GPE) and DM6CC, DM6CC remarkably accelerated the polymerization rate of GPE and also effectively suppressed chain‐transfer reactions, which occur in the homopolymerization of the epoxide. This suppression resulted in the formation of the corresponding copolymer with a higher molecular weight. Similar effects of DM6CC were also observed in a curing system with a Novolac‐type multifunctional epoxide (Novolac glycidyl ether). The curing reaction of the epoxide in the presence of DM6CC smoothly proceeded and yielded the corresponding networked polymer, showing a decrease in the volume shrinkage as the DM6CC content increased. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 372–378, 2005     

Synthesis and characterization of homo‐ and copolymers of 3‐(2‐cyano ethoxy)methyl‐ and 3‐[methoxy(triethylenoxy)]methyl‐3′‐methyl‐oxetane

Two oxetane‐derived monomers 3‐(2‐cyanoethoxy)methyl‐ and 3‐(methoxy(triethylenoxy)) methyl‐3′‐methyloxetane were prepared from the reaction of 3‐methyl‐3′‐hydroxymethyloxetane with acrylonitrile and triethylene glycol monomethyl ether, respectively. Their homo‐ and copolyethers were synthesized with BF₃· Et₂O/1,4‐butanediol and trifluoromethane sulfonic acid as initiator through cationic ring‐opening polymerization. The structure of the polymers was characterized by FTIR and¹H NMR. The ratio of two repeating units incorporated into the copolymers is well consistent with the feed ratio. Regarding glass transition temperature (T_g), the DSC data imply that the resulting copolymers have a lower T_g than pure poly(ethylene oxide). Moreover, the TGA measurements reveal that they possess in general a high heat decomposition temperature. The ion conductivity of a sample (P‐AN 20) is 1.07 × 10^?5 S cm^?1 at room temperature and 2.79 × 10^?4 S cm^?1 at 80 °C, thus presenting the potential to meet the practical requirement of lithium ion batteries for polymer electrolytes. Copyright © 2005 Society of Chemical Industry     

Curing behaviors and thermal properties of benzoxazine and N,N′‐(2, 2, 4‐trimethylhexane‐1, 6‐diyl) dimaleimide blend

A blend of bisphenol‐A based benzoxazine (BA‐a)/N, N′‐(2, 2, 4‐Trimethylhexane‐1, 6‐diyl) dimaleimide (TBMI) with the ratio of 1:1 was prepared and its curing behaviors were studied by differential scanning calorimetry (DSC), Fourier Transform Infrared (FTIR). The curing mechanism was proposed based on the semiquantitative analysis from FTIR spectra. The model compound was used to study the catalysis effect of BA‐a on the curing reaction of TBMI. It was found the curing reactions of BA‐a and TBMI not only proceeded simultaneously, but their coreactions also occurred. The research further indicated that negative oxygen ions from ring opening of benzoxazine mainly promoted the polymerization of maleimide groups, even though the amine group of benzoxazine had a positive effect on the reaction of maleimide groups. Besides, BA‐a and TBMI blends showed improved thermal properties based on the results from DMA and TGA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Influence of semi‐crystalline poly(ε‐caprolactone) and non‐crystalline polylactide blocks on the thermal properties of polydimethylsiloxane‐based block copolymers

Poly(A)‐block‐poly(B), poly(A)‐block‐poly(B)‐block‐poly(A) and B(A)₂ block copolymers were prepared through coordinated anionic ring‐opening polymerization of ε‐caprolactone (CL) and lactic acid (LA) using hydroxy‐terminated polydimethylsiloxane (PDMS) as initiator. A wide range of well‐defined combinations of PDMS‐block‐PCL and PDMS‐block‐PLA diblock copolymers, PCL‐block‐PDMS‐block‐PCL and PLA‐block‐PDMS‐block‐PLA triblock copolymers and star‐PDMS(PCL)₂ copolymers were thus obtained. The number‐average molar masses and the structure of the synthesized block copolymers were identified using various analytical techniques. The thermal properties of these copolymers were established using differential scanning calorimetry. Considering PDMS‐block‐PCL copolymers, the results demonstrate the complex effect of polymer architecture and PCL block length on the ability of the PDMS block to crystallize or not. In the case of diblock copolymers, crystallization of PCL blocks originated from stacking of adjacent chains inducing the extension of the PDMS block that can easily crystallize. In the case of star copolymers, the same tendency as in triblock copolymers is observed, showing a limited crystallization of PDMS when the length of the PCL block increases. In the case of PDMS‐block‐PLA copolymers, melting and crystallization transitions of the PLA block are never observed. Considering the diblock copolymers, PDMS sequences have the ability to crystallize. © 2019 Society of Chemical Industry     

Synthesis and characterization of poly(4‐diphenylaminostyrene)‐Poly(9‐vinylanthracene) binary block copolymer

Block copolymerization of plural types of monomers offers a new opportunity for the preparation of a variety of multifunctional polymers. Poly(4‐diphenylaminostyrene) (PDAS)‐poly(9‐vinylanthracene) (PVAN) binary block copolymer (PDAS‐PVAN) was synthesized by (living) anionic polymerization using the benzyllithium/N,N,N′,N′‐tetramethylethylenediamine system. The photoluminescence emission of PDAS‐PVAN was enhanced by the fluorescence resonance energy transfer from PDAS block to PVAN block in PDAS‐PVAN. The hole drift mobility of the copolymer was controllable by the amount of triphenylamino groups in the polymer chain. The optical and electrical properties of PDAS‐PVAN were adjustable through the polymer chain structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

New polymer materials based on silicone‐acrylic copolymer to improve fastness properties of reactive dyes on cotton fabrics

New polymer materials, based on silicone‐acrylic copolymer containing cationic groups, were synthesized through radical mechanism and ring‐opening polymerization of cyclosiloxane. The polymers of polyacrylate/polysiloxane improved the fastness properties of reactive dyes on cotton. In comparison with those of polyacrylate‐containing cationic groups, the wash fastness and wet rubbing fastness of the dyed cotton fabric treated with the new polymer materials were better. The handle of the fabric with aftertreatment was also good. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 720–725, 2006     

Structure and morphology of poly(β‐hydroxybutyrate) synthesized by ring‐opening polymerization of racemic (R,S)‐β‐butyrolactone with distannoxane derivatives

Predominantly syndiotactic poly((R,S)‐β‐hydroxybutyrate) (PHB) was synthesized by ring‐opening polymerization of racemic β‐butyrolactone with distannoxane derivatives as catalysts. We have studied the polymerization of (R,S)‐β‐BL using distannoxane derivatives as catalysts and the effects of polymerization time on crude yield and molecular weight of the polymers obtained. Then, a more detailed study of the characterization of polymers obtained using hydroxy‐ and ethoxy‐distannoxanes was performed. ¹³C NMR spectroscopy resolved stereosequences in synthetic PHB at the diad level for the carbonyl carbon and at the triad level for the methylene carbon. These analyses show that distannoxane catalysts produce preferentially syndiotactic polyesters (syndiotactic diads fraction from 0.56 to 0.61). Triad stereosequence distribution of PHB samples agrees favourably with the Bernoullian statistical model of chain‐end control, where ideally Φ = 4(mm) (rr)/(mr + rm)² = 1 for perfect chain‐end control. Polymer samples synthesized from distannoxane catalysts are composed of two distinct transition endotherm components with peak temperatures of approximately 42 °C and 75 °C. The formation of two melting endotherms may be due to the presence of two different crystalline structures. © 2000 Society of Chemical Industry     

Synthesis of ω‐functionalized poly(1,3‐cyclohexadiene): addition of fluorescent functional group to the polymer chain end

BACKGROUND: Poly(1,3‐cyclohexadiene) (PCHD) is of interest as a precursor for the synthesis of a new class of high‐performance hydrocarbon polymers. ω‐Functionalization of PCHD offers a new opportunity for the preparation of a variety of multifunctional PCHD derivatives. RESULTS: ω‐Functionalized PCHD containing a fluorenyl (or anthracenyl) group at the polymer chain end was successfully synthesized by post‐polymerization reaction of poly(1,3‐cyclohexadienyl)lithium (PCHDLi) with alkyl halides containing a fluorescent functional group. The degree of nucleophilicity of PCHDLi and the control of side reactions were very important factors to achieve a high conversion for the post‐polymerization reactions of PCHDLi. The ω‐functionalized PCHDs obtained exhibited strong photoluminescence and the wavelength of the fluorescence was adjustable by changing the structure of the ω‐functional group. CONCLUSION: ω‐Functionalized PCHD is a preferable precursor that can be utilized to obtain a new class of multifunctional hydrocarbon polymers containing six‐membered rings in the main chain. Copyright © 2007 Society of Chemical Industry     

A novel initiating system for ring‐opening polymerization of ε‐caprolactone: Synthesis of triarm star‐shaped poly(ε‐caprolactone)

The rare earth compound, scandium trifluoromethanesulfonate [Sc(OTf)₃], has been used as a water‐tolerant catalyst for the synthesis of star‐shaped poly(ε‐caprolactone)s (SPCLs) with trimethylol propane as trifunctional initiator in solvent at 40°C. Triarm SPCLs have been successfully prepared. The molar mass of SPCLs were determined by end‐group ¹H NMR analyses, which could be well controlled by the molar ratio of the monomer to the initiator, and were independent of the amount of Sc(OTf)₃ used. Differential scanning calorimetry analyses suggested that the maximal melting point, the cold crystallization temperature, and the degree of crystallinities of SPCLs increased with the increasing of the molar mass and were lower than the linear poly(ε‐caprolactone) (LPCL) with similar molar mass. Furthermore, polarized optical microscopy indicated that LPCL showed fast crystallization rate and good spherulitic morphology with apparent Maltese cross pattern, whereas SPCLs exhibit much lower crystallization rate and poor spherulitic morphology. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A new macroinitiator for the synthesis of triblock copolymers PA12‐b‐PDMS‐b‐PA12

A new PDMS macroinitiator is proposed for the anionic ring‐opening polymerization of lactams. This α,ω‐dicarbamoyloxy caprolactam PDMS macroinitiator was readily obtained in quantitative yield, by an original synthesis scheme in two steps, which involved the scarcely reported reaction of isocyanates with silanol groups. It was then shown that this bifunctional macroinitiator enabled to synthesize triblock copolymers PA12‐b‐PDMS‐b‐PA12 by polymerization of lauryl lactam (LL) at high temperature (200°C) in inert atmosphere under conditions compatible with reactive extrusion processes. Another related high molar weight α,ω‐diacyllactam PDMS macroinitiator was also successfully used in the polymerization of LL under the same conditions, therefore overcoming the limitations formerly reported for this type of macroinitiators during the polymerization ε‐caprolactam (ε‐CL) at a much lower temperature (80°C). Triblock copolymers with a wide range of PA12 /molar weights (M_n: ～ 10,800–250,000 Da) were eventually obtained by using both types of macroinitiators. DMTA and DSC analyses showed that their thermal properties were strongly dependent upon their respective contents in soft and hard blocks. Such triblock copolymers already appear very promising for the highly effective in situ compatibilization of PA12/PDMS blends as shown by recent complementary results obtained in our laboratory. © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 2818–2831, 2006     

Poly(ε‐caprolactone)‐grafted acetylated anhydroglucose oligomer by ring‐opening polymerization—Synthesis and characterization

A novel acetylated anhydroglucose oligomer (AGU‐oligomer), prepared by acid catalyzed transglycosidation of potato starch triacetate and ethylene glycol, was used as a multifunctional coinitiator for the ring‐opening polymerization of ε‐caprolactone (ε‐CL). The polymers were synthesized using different weight ratios of the starting materials and were characterized by NMR, SEC, and MALLS. The results confirmed the expected P(AGU/CL) polymer structure, namely a ‘comb‐like’ graft‐copolymer having the AGU oligomer as backbone with PCL grafts of variable chain lengths (L_CL = 4–21). Thermal and mechanical properties of graft‐copolymers with different ε‐CL block lengths were examined. By changing the graft length, crystallinity was controlled and amorphous polymers were obtained with AGU‐oligomer contents higher than 50 wt %. The tensile properties varied with the composition and a copolymer having 40 wt % of AGU‐oligomer behaved like soft elastomer, showing high elongation at break. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1633–1641, 2006     

Synthesis of poly (γ‐benzyl‐L‐glutamate) with well‐defined terminal structures and its block polypeptides with alanine,leucine and phenylalanine

The ring‐opening polymerization of γ‐benzyl‐L ‐glutamate N‐carboxyanhydride (BLG‐NCA) was initiated by n‐hexylamine in N,N‐dimethyformamide under normal pressure at 0 °C. The products were characterizated by gel permeation chromatography, matrix‐assisted laser desorption/ionization time of flight mass spectroscopy (MALDI‐TOF MS), nuclear magnetic resonance etc. MALDI‐TOF MS gave direct evidence that the side reactions during the polymerization of BLG‐NCA could be greatly reduced by decreasing the reaction temperature, e.g. from room temperature to 0 °C. As a result, over 90% of the products were amino‐terminated poly(γ‐benzyl‐L ‐glutamate) (PBLG) with low polydispersity index when the polymerization was carried out at 0 °C, which could be used to re‐initiate the polymerization of other NCAs. Then several well‐defined PBLG‐containing block copolypeptides were successfully synthesized in a convenient way. Copyright © 2012 Society of Chemical Industry     

Ring‐opening polymerization of ε‐caprolactone with a divalent samarium bis(phosphido) complex

The ring‐opening polymerization of ε‐caprolactone initiated with a divalent samarium bis(phosphido) complex [Sm(PPh₂)₂] is reported. The polymerization proceeded under mild reaction conditions and resulted in polyesters with number‐average molecular weights of 8.2 × 10³ to 12.5 × 10³. The yield and molecular weight of poly(ε‐caprolactone)s were dependent on the experimental parameters, such as the monomer/initiator molar ratio, the monomer concentration, the reaction temperature, and the polymerization time. The obtained polymers were characterized with Fourier transform infrared, NMR, gel permeation chromatography, and differential scanning calorimetry. On the basis of an end‐group analysis of low‐molecular‐weight polymers by NMR spectroscopy, a coordination–insertion mechanism is proposed for the polymerization. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1558–1564, 2005     

Polyethylene‐block‐poly(ε‐caprolactone) diblock copolymers: synthesis and compatibility

A strategy is introduced for the synthesis of polyethylene‐block‐poly(ε‐caprolactone) block copolymers by a combination of coordination polymerization and ring‐opening polymerization. First, end‐hydroxylated polyethylene (PE‐OH) was prepared with a one‐step process through ethylene/3‐buten‐1‐ol copolymerization catalyzed by a vanadium(III) complex bearing a bidentate [N,O] ligand ([PhN?C(CH₃)CHC(Ph)O]VCl₂(THF)₂). The PE‐OH was then used as macroinitiator for ring‐opening polymerization of ε‐caprolactone, leading to the desired nonpolar/polar diblock copolymers. The block structure was confirmed by spectral analysis using ¹H NMR, gel permeation chromatography and differential scanning calorimetry. The unusual topologies of the model copolymers will establish a fundamental understanding for structure–property correlations, e.g. compatibilization, of polymer blends and surface and interface modification of other polymers. © 2014 Society of Chemical Industry     

Synthesis and properties of polycarbonate copolymers of trimethylene carbonate and 2‐phenyl‐5,5‐bis(hydroxymethyl) trimethylene carbonate

The polycarbonate copolymers poly[trimethylene carbonate‐co‐2‐phenyl‐5,5‐bis(hydroxymethyl) trimethylene carbonate] [P(TMC‐co‐PTC)] were synthesized by the ring‐opening polymerization of trimethylene carbonate (TMC) and 2‐phenyl‐5,5‐bis(hydroxymethyl) trimethylene carbonate (PTC) with tin(II) 2‐ethylhexanoate and aluminum isopropoxide as the catalysts. These copolymers were further reduced by a palladium/carbonate (Pd/C; 10%) catalyst to produce partly deprotected copolymers. These two types of copolymers were characterized by ¹H‐NMR, Fourier transform infrared spectroscopy, UV spectroscopy, gel permeation chromatography, differential scanning calorimetry, and an automatic contact angle meter. The influences of the feed molar ratio of the monomers, the catalyst concentration, the reaction time, and the reaction temperature on the copolymerization process were also studied. The copolymerization of the TMC and PTC monomers was a nonideal copolymerization, and the copolymerization reactivity ratio of TMC was higher than that of PTC. In vitro degradation tests indicated that the partly deprotected copolymers possessed faster degradation rates and more hydrophilicity than the corresponding unreduced copolymers. Moreover, the degradation of these two type copolymers increased when the pH value of the buffer solutions decreased. In vitro drug‐release experiments showed that these two types of copolymers had steady drug‐release rates and good controlled release properties. Moreover, the partly deprotected copolymers had faster drug‐release rates than the corresponding unreduced copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012