Synthesis of poly(cyanurate)s by a novel polyaddition of bis(epoxide)s with triazine dichloride

Poly(cyanurate)s (P‐1–P‐4) containing triazine groups in the main chain and pendant chloromethyl groups in the side chain were synthesized by the polyaddition of bis(epoxide)s with 2,4‐dichloro‐6‐(diphenylamino)‐s‐triazine (DPAT) using quaternary onium salts as catalysts. The polyaddition of diglycidyl ether of bisphenol‐A (DGEBA) with DPAT proceeded smoothly in chlorobenzene at 100 °C for 12 h to give P‐1 with M_n = 19,000 in a 92% yield, when tetrabutylammonium chloride (TBAC) was used as a catalyst. However, no reaction occurred without a catalyst or with triethylamine alone under the same reaction conditions. Polyadditions of other bis(epoxide)s with DPTA also proceeded smoothly using 5 mol % of TBAC as a catalyst in chlorobenzene to produce corresponding polymers (P‐2≈P‐4) in high yields under similar reaction conditions. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4006–4012, 2000     

Novel synthesis of reactive polycarbonates with pendant chloromethyl groups by the polyaddition of bis(oxetane)s with 2,2′‐bis[(4‐chloroformyl)oxyphenyl]propane

The polyaddition of 1,4‐bis[(3‐ethyl‐3‐oxetanyl)methoxymethyl]benzene with 2,2′‐bis[(4‐chloroformyl)oxyphenyl]propane was examined with quaternary onium salts as catalysts. When the polyaddition was carried out with tetrabutylphosphonium bromide in chlorobenzene at 120 °C for 24 h, the corresponding poly(alkyl aryl carbonate) with a high molecular weight (number‐average molecular weight = 16,700) was obtained in an almost quantitative yield. It was found from the ¹H NMR and ¹³C NMR spectra of the obtained polymer that the addition reaction proceeded without any side reactions, providing the polycarbonate with pendant chloromethyl groups in the side chain. The polyaddition of bis{[3‐(3‐ethyloxetanyl)]methyl}terephthalate also proceeded smoothly and gave the corresponding polycarbonate with high molecular weight in a good yield. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2304–2311, 2003     

Synthesis of polyesters with pendant oxetane groups by the chemoselective alternating copolymerization of 3‐ethyl‐3‐(glycidyloxymethyl)oxetane with carboxylic anhydride and its photochemical reaction

The synthesis of polyesters with pendant oxetane groups by the chemoselective alternating copolymerization of 3‐ethyl‐3‐(glycidyloxymethyl)oxetane (EGMO) with carboxylic anhydride and the photochemical reaction of the resulting polymer was examined. The alternating copolymerization of EGMO with phthalic anhydride proceeded chemoselectively with quaternary onium salts under appropriate reaction conditions, and the corresponding soluble polymers with pendant oxetane groups with number‐average molecular weights of 4700–7200 were obtained in 72–87% yields. Furthermore, the photochemical reaction of the resulting polymers was examined with certain photoacid generators in the film state upon UV irradiation, and it was found that the photocrosslinking reaction of the pendant oxetane groups proceeded smoothly to give the insoluble polymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1952–1961, 2003     

Synthesis of poly(silyl ether)s containing pendant chloromethyl groups by the polyaddition of bis(oxetane)s with dichlorosilanes

The polyaddition of bis(3‐ethyl‐3‐oxetanylmethyl) terephthalate (BEOT) with dichlorodiphenylsilane (CPS) using tetrabutylammonium bromide (TBAB) as a catalyst proceeded under mild reaction conditions to afford a polymer containing silicon atoms in the polymer main chain. A poly(silyl ether) (P‐1) with a high molecular weight (M_n = 53,200) was obtained by the reaction of BEOT with CPS in the presence of 5 mol % of TBAB in toluene at 0 °C for 1 h and then at 50 °C for 24 h. The structure of the resulting polymer was confirmed by IR and ¹H NMR spectra. Furthermore, it was proved that the polyaddition of certain bis(oxetane)s with dichlorosilanes proceeds smoothly to give corresponding poly(silyl ether)s with TBAB as the catalyst. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2254–2259, 2000     

Synthesis and characterization of fluorine‐containing polyesters by the polyaddition of bis(epoxide)s with active diesters

The synthesis and optical properties of polyesters with pendant fluorinated phenoxy groups were examined. The polyaddition of bisphenol AF diglycidyl ether ( 1 ) with fluorine‐containing terephtalates ( 2a–f ) was carried out with tetrabutylphosphonium chloride (TBPC) as the catalyst in chlorobenzene to afford the corresponding polyesters with number‐average molecular weights (M_n's) ranging from 15,200 to 30,000 in 88–96% yields. Furthermore, the polyaddition of 1 with isophthalate 2g and phthalate 2h also produced high‐molecular‐weight polyesters with M_n's = 22,700 and 22,600 in 88 and 84% yields, respectively. The linear relationship was observed between the fluorine contents and refractive indices of the obtained polyesters. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 213–222, 2003     

Novel synthesis of polyphosphonates by the polyaddition of bis(epoxide) with diaryl phosphonates

The polyaddition of bisphenol A diglycidyl ether (BPGE) with bis(4‐chlorophenyl) phenylphosphonate was carried out using quaternary onium salts or crown ether complexes as catalysts. When the polyaddition was performed using tetrabutylammonium chloride, tetrabutylphosphonium chloride, or 18‐crown‐6/KCl in N‐ methyl‐2‐pyrrolidone at 110°C for 48 h, the corresponding polyphosphonate with moderated molecular weights was obtained in 88–96% yields. The structure of the resulting polyphosphonate was confirmed by IR and ¹H‐NMR spectra. The polyaddition of BPGE with various diaryl phosphonates also proceeded very smoothly to produce the corresponding polyphosphonates with moderate molecular weights. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 959–965, 1999     

Synthesis of macrocycles by the ring‐crossover reaction of a cyclic dithioester

The ring‐crossover polymerization of cyclic dithioester 1 was performed in the presence of quaternary onium salts as catalysts at 70–150 °C for 24 h in NMP. It was found that predictable cyclic polymers with the same repeating structures as 1 were obtained with M_ns in the range between 700 and 3,500, quantitatively. It was observed that intermolecular and intramolecular thioester‐exchange reactions proceeded between cyclic monomer 1 and resulting cyclic polymers under thermodynamic control to give a lower‐molecular‐weight cyclic polymer with a lower polydispersity ratio (M_n = 2,400, M_w/M_n = 1.70). © 2006Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 680–687, 2007     

Synthesis and characterization of fluoropolymers by the polyaddition of bis(epoxide)s with dicarboxylic acids and diols

The synthesis and characterization of the fluoropolymers poly 1a – 1d and poly 2a – 2d with pendant hydroxyl groups were examined. The polyaddition of bis(epoxide)s [2,2′‐bis(4‐glycidyletherphenyl)hexafluoropropane and bisphenol A diglycidyl ether] with dicarboxylic acids (tetrafluoroterephthalic acid and terephthalic acid) and diols [2,2′‐bis(4‐hydroxyphenyl)hexafluoropropane, 2,2′,3,3′,5,5′,6,6′‐octafluoro‐4,4′‐biphenol, 1,4‐bis(hexafluorohydroxyisopropyl)benzene, and 1,3‐bis(hexafluorohydroxyisopropyl)benzene] was carried out at 50–100 °C for 6–48 h in the presence of quaternary onium salts (tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylphosphonium bromide, and tetrabutylphosphonium chloride; 2.5 mol %) as catalysts in dimethyl sulfoxide, N‐methylpyrrolidone, dimethylformamide, dimethylacetamide, dioxane, diglyme, o‐dichlorobenzene, chlorobenzene, and toluene to afford the corresponding polymers, poly 1a – 1d and poly 2a – 2d , with number‐average molecular weights of 11,000–59,400 in 45–97% yields. The solubility of the obtained polymers was good, and their thermal stability might be assumed from their structures. A linear relationship was observed between the contents of the fluorine atoms and the refractive indices. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1395–1404, 2002     

Synthesis of polymers with pendant hydroxyl groups by polyaddition of bis(oxetane)s with dithiols

Addition reaction of (3-methyl-3-oxetanyl)methyl acetate (MOMA) with bis(4-mercaptophenyl) sulfide (BMPS) was examined in certain organic solvents. When the reaction of MOMA with BMPS was performed without any catalyst in hexamethylphosphoric triamide (HMPA) and N-methyl-2-pyrrolidone (NMP) at 130°C for 24 h, conversions of the corresponding adduct were 96 and 36%, respectively, which was confirmed by ¹H-NMR spectra. On the other hand, when the reaction was carried out using tetraphenylphosphonium bromide (TPPB) as a catalyst under the same conditions, conversions of the adduct were 96 and 81% in HMPA and NMP, respectively. This result shows that although the addition reaction of oxetane compound with aromatic dithiol proceeds without any catalyst in HMPA, the reaction was strongly enhanced by adding TPPB in NMP. On the basis of the above results, polyadditions of bis((3-methyl-3-oxetanyl)methyl) terephthalate (BMOT) and bis((3-ethyl-3-oxetanyl)methyl) terephthalate with BMPS were performed using TPPB as the catalyst in NMP at 130°C for 24 h. As a result, the corresponding high molecular weight polymers 1 (M_n = 22,400) and 2 (M_n = 12,800) with pendant primary hydroxyl groups were obtained in 83 and 89% yields without any gel products, respectively. Furthermore, a low molecular weight oligomer was obtained from the polyaddition of BMOT with aliphatic dithiol, bis(mercaptomethyl)benzene, under the same reaction conditions. The catalytic activity on the polyaddition of BMOT with BMPS was also examined, and it was found that thermally stable TPPB and crown ether complexes at the reaction temperature (130°C) have higher catalytic activity than tetrabutylammonium bromide and tetrabutylphosphonium bromide to produce polymer 1 with high molecular weight. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2873–2880, 1998     

A novel polyaddition of bis(epoxide)s with triazine diaryl ether for the synthesis of poly(ether)s containing triazine group in the main chain

Poly(ether)s (P‐1–P‐4) containing triazine groups in the main chain and pendant phenoxy groups in the side chain were synthesized by the polyaddition of bis(epoxide)s with 2,4‐di‐(p‐chlorophenoxy)‐6‐(diphenylamino)‐s‐triazine (DCTA) with quaternary onium salts or crown ether complexes as catalysts. The polyaddition of diglycidyl ether of bisphenol A with DCTA proceeded smoothly in chlorobenzene at 120 °C for 24 h to give P‐1 with a number‐average molecular weight of 24,800 in a 95% yield when tetraphenylphosphonium chloride (TPPC) was used as a catalyst; however, no reaction occurred without a catalyst under the same reaction conditions. Polyadditions of other bis(epoxide)s with DCTA also proceeded smoothly with 5 mol % TPPC as a catalyst in chlorobenzene to produce the corresponding polymers (P‐2–P‐4) in high yields under similar reaction conditions. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3604–3611, 2000     

Synthesis and characterization of poly(3,3 bis(azidomethyl)oxetane‐co‐ε‐caprolactone)s

The quasi‐living cationic copolymerization of 3,3‐bis(chloromethyl)oxetane (BCMO) and ε‐caprolactone (ε‐CL), using boron trifluoride etherate as catalyst and 1,4‐butanediol as coinitiator, was investigated in methylene chloride at 0°C. The resulting hydroxyl‐ended copolymers exhibit a narrow molecular weight polydispersity and a functionality of about 2. The reactivity ratios of BCMO (0.26) and ε‐CL (0.47), and the T_g of the copolymers, indicate their statistical character. The synthesis of poly(3,3‐bis(azidomethyl)oxetane‐co‐ε‐caprolactone) from poly(BCMO‐co‐ε‐CL) via the substitution of the chlorine atoms by azide groups, using sodium azide in DMSO at 110°C, occurs without any degradation, but the copolymers decompose at about 240°C. All polymers were characterized by vapor pressure osmometry or steric exclusion chromatography, ¹H‐NMR and FTIR spectroscopies, and DSC. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1027–1039, 1999     

Polymerization of 2‐pentene with Ni(II) α‐diimine complex/M‐MAO catalyst and structure of the polymer

Polymerization of 2‐pentene with [ArN?C(An)C(An)·NAr)NiBr₂ (Ar?2,6‐iPr₂C₆H₃)] ( 1‐Ni) /M‐MAO catalyst was investigated. A reactivity between trans‐2‐pentene and cis‐2‐pentene on the polymerization was quite different, and trans‐2‐pentene polymerized with 1‐Ni /M‐MAO catalyst to give a high molecular weight polymer. On the other hand, the polymerization of cis‐2‐butene with 1‐Ni /M‐MAO catalyst did not give any polymeric products. In the polymerization of mixture of trans‐ and cis‐2‐pentene with 1‐Ni /M‐MAO catalyst, the M_n of the polymer increased with an increase of the polymer yields. However, the relationship between polymer yield and the M_n of the polymer did not give a strict straight line, and the M_w/M_n also increased with increasing polymer yield. This suggests that side reactions were induced during the polymerization. The structures of the polymer obtained from the polymerization of 2‐ pentene with 1‐Ni /M‐MAO catalyst consists of ? CH₂? CH₂? CH(CH₂CH₃)? , ? CH₂? CH₂? CH₂? CH(CH₃)? , ? CH₂? CH(CH₂CH₂CH₃)? , and methylene sequence ? (CH₂)_n? (n ≥ 5) units, which is related to the chain walking mechanism. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2858–2863, 2008     

Pd(0)‐catalyzed polyaddition of bifunctional vinyloxiranes with phenol derivatives: The synthesis of polymers containing an allyl aryl ether moiety in the main chain

The palladium(0)‐catalyzed polyaddition of bifunctional vinyloxiranes [1,4‐bis(2‐vinylepoxyethyl)benzene ( 1a ) and 1,4‐bis(1‐methyl‐2‐vinylepoxyethyl)benzene ( 1b )] with oxygen nucleophiles such as hydroquinone and bisphenol A gave new unsaturated polyethers containing an allyl aryl ether moiety and pendant hydroxy groups. The polyaddition with 1a was largely affected by the phosphine ligands employed and the reaction temperature. The polyaddition with hydroquinone and bisphenol A was conducted at room temperature for 24 h in tetrahydrofuran in the presence of PPh₃ and gave the desired polyethers in good yields, the number‐average molecular weights (M_n) of which were 5700 and 7700, respectively. 1,2‐Bis(diphenylphosphino)ethane (dppe) was not effective in the polyaddition with 1a . The polyaddition of 1b with hydroquinone and bisphenol A gave the corresponding polyethers despite the kinds of ligands employed (PPh₃ and dppe), contrary to the polyaddition with 1a . The polyaddition of 1b with 4,4′‐biphenol was also carried out in the presence of Pd₂(dba)₃ · CHCl₃/dppe as a catalyst (where dba is dibenzylideneacetone) and afforded the expected polyether with a high M_n value (M_n = 24,900). In addition, vinyloxirane 1b could reacted with racemic 1,1′‐bi‐2‐naphthol to give the corresponding polyether in a good yield. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 476–482, 2003     

Synthesis of polyphosphonates containing pendant chloromethyl groups by the polyaddition of bis(oxetane)s with phosphonic dichlorides

The polyaddition of 4,4′‐bis[(3‐ethyl‐3‐oxetanyl)methoxy]biphenyl (4,4′‐BEOBP) and phenylphosphonic dichloride (PPDC) with quaternary onium salts as catalysts proceeded under mild reaction conditions to afford a polymer containing phosphorous atoms in its main chain. A polyphosphonate with a high number‐average molecular weight (10,300) was obtained by the reaction of 4,4′‐BEOBP and PPDC in the presence of tetraphenylphosphonium chloride (TPPC) in o‐dichlorobenzene at 130 °C for 24 h. The structure of the resulting polymer was confirmed with IR, ¹H NMR, and ³¹P NMR spectroscopy. Furthermore, it was proved that the polyaddition of certain bis(oxetane)s with phosphonic dichlorides proceeded smoothly to give corresponding polyphosphonates with TPPC as the catalyst. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3835–3846, 2002     

Catalytic reactions of oxetanes with protonic reagents and aprotic reagents leading to novel polymers

This paper reports new addition reactions of oxetanes with certain protonic reagents such as carboxylic acid, phenol, and thiol, and with certain aprotic reagents such as acyl chloride, thioester, phosphonyl dichloride, silyl chloride, and chloroformate using quaternary onium salts as catalysts. The kinetic study of the addition reactions of oxetanes was also investigated. These new addition reactions were applicable to the synthesis of new polymers. These polyaddition systems could also construct both polymer main chains and reactive side chains. The alternating copolymerization of oxetanes with carboxylic anhydride was performed. Furthermore, it was found that anionic ring‐opening polymerization of oxetanes containing hydroxy groups proceeded to afford the hyperbranched polymer (HBP) with an oxetanyl group and many hydroxy groups at the ends of the polymer chains. Alkali developable photofunctional HBPs were synthesized by the polyaddition of bis(oxetane)s or tris(oxetane)s, and their patterning properties were examined, too. The photo‐induced cationic polymerization of the polymers with pendant oxetanyl groups and the thermal curing reactions of polyfunctional oxetanes (oxetane resins) were also examined to give the crosslinking materials quantitatively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 709–726, 2007     

The kinetics of polycondensation of α,α′‐dichloro‐p‐xylene with 4,4′‐isopropylidenediphenol using benzyltriethylammonium chloride as a phase‐transfer catalyst

The phase‐transfer catalyzed polycondensation of α,α′‐dichloro‐p‐xylene with 4,4′‐isopropylidenediphenol was carried out using benzylethylammonium chloride in a two‐phase system of an aqueous alkaline solution and benzene at 60 °C under nitrogen atmosphere. The rate of polycondensation was expressed as the combined terms of quaternary onium cation and 4,4′‐isopropylidenediphenolate anion rather than the feed concentration of catalyst and 4,4′‐isopropylidenediphenol. The measured concentrations of hydroxide and chloride anion in the aqueous solution and α,α′‐dichloro‐p‐xylene in the organic phase were used to obtain the reaction rate constant with the integral method, and to analyze the polycondensation mechanism with a cyclic phase‐transfer initiation step in the heterogeneous liquid–liquid system. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3059–3066, 2000     

Novel synthesis of polyethers by the polyaddition of bis(epoxide)s with bis(phosphinate)s

The polyaddition of bisphenol A diglycidyl ether with bis[4‐(P,P‐diphenylphosphinyloxy)phenyl] sulfone catalyzed by quaternary onium salt, such as tetrabutylammonium chloride afforded a new phosphorus‐containing polyether with good solubility in common organic solvents. Having studied various factors affecting the reaction, such as temperature, catalyst concentration, reaction time, etc., an appropriate polyaddition condition was suggested as using 5 mol % of suitable quaternary ammonium or phosphonium salt in polar solvent at 150°C within 25 h in an ampule for producing high molecular weight polymer. A number of polyethers bearing pendent phosphinate ester groups from the polyaddition of certain bis(epoxide)s and bis(phosphinate)s were synthesized under the above condition and characterized by GPC, IR, and NMR. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1009–1016, 1999     

Random poly(3‐hexylthiophene‐co‐3‐cyanothiophene‐co‐3‐(2‐ethylhexyl)thiophene) copolymers with high open‐circuit voltage in polymer solar cells

For the purpose of developing poly(3‐hexylthiophene) (P3HT) based copolymers with deep‐lying highest occupied molecular orbital (HOMO) levels for polymer solar cells with high open‐circuit voltage (V_oc), we report a combined approach of random incorporation of 3‐cyanothiophene (CNT) and 3‐(2‐ethylhexyl)thiophene (EHT) units into the P3HT backbone. This strategy is designed to overcome CNT content limitations in recently reported P3HT‐CNT copolymers, where incorporation of more than 15% of CNT into the polymer backbone leads to impaired polymer solubility and raises the HOMO level. This new approach allows incorporation of a larger CNT content, reaching even lower‐lying HOMO levels. Importantly, a very low HOMO level of ?5.78 eV was obtained, representing one of the lowest HOMO values for exclusively thiophene‐based polymers. Lower HOMO levels result in higher V_oc and higher power conversion efficiencies (PCE) compared to the previously reported P3HT‐CNT copolymers containing only 3‐hexylthiophene and CNT units. As a result, solar cells based on P3HT‐CNT‐EHT(15:15) , which contains 70% of P3HT, 15% of CNT and 15% of EHT, yield a V_oc of 0.83 V in blends with PC₆₁BM while preserving high fill factor (FF) and high short‐circuit current density (J_sc), resulting in 3.6% PCE. Additionally, we explored the effect of polymer number‐average molecular weight (M_n) on the optoelectronic properties and solar cell performance for the example of P3HT‐CNT‐EHT(15:15). The organic photovoltaic (OPV) performance improves with polymer M_n increasing from 3.4 to 6.7 to 9.6 kDa and then it declines as M_n further increases to 9.9 and to 16.2 kDa. The molecular weight study highlights the importance of not only the solar cell optimization, but also the significance of individual polymer properties optimization, in order to fully explore the potential of any given polymer in OPVs. The broader ramification of this study lies in potential application of these high band gap copolymers with low‐lying HOMO level in the development of ternary blend photovoltaics as well as tandem OPV. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1526–1536     

Cationic ring‐opening polymerization of ϵ‐thionocaprolactone: Selective formation of polythioester

Cationic ring‐opening polymerization of ϵ‐thionocaprolactone was examined. The corresponding polythioester with the number‐average molecular weight (M_n ) of 57,000 was obtained in the polymerization with 1 mol % of BF₃ · OEt₂ as an initiator in CH₂Cl₂ at 28 °C for 5 h with quantitative monomer conversion. The M_n of the polymer increased with the solvent polarity and monomer‐to‐initiator ratio. No polymerization took place below −30 °C, and the monomer conversion and M_n of the polymer increased with the temperature in the range of −15 to 28 °C. The increase of initial monomer concentration was effective to improve the monomer conversion and the M_n of the obtained polymer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4057–4061, 2000     

Synthesis and characterization of a novel soluble reactive ladder‐like polysilsesquioxane with side‐chain 2‐(4‐chloromethyl phenyl) ethyl groups

A new kind of soluble structure‐ordered ladder‐like polysilsesquioxane with reactive side‐chain 2‐(4‐chloromethyl phenyl) ethyl groups ( L ) was first synthesized by stepwise coupling polymerization. The monomer, 2‐(4‐chloromethyl phenyl) ethyltrichlorosilane ( M ), was synthesized successfully by hydrosilylation reaction with dicyclopentadienylplatinum(II) chloride (Cp₂PtCl₂) ­catalyst. Monomer and polymer structures were characterized by FT‐IR, ¹H‐NMR, ¹³C‐NMR, ²⁹Si‐NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vapor pressure osmometry (VPO) and X‐ray diffraction (XRD). This novel reactive ladder‐like polymer has promise potential applications as initiator for atom transfer radical polymerization, and as precursor for a variety of advanced functional polymers. Copyright © 2001 John Wiley & Sons, Ltd.