Synthesis and characterization of alt‐copoly [oligosiloxane/1,4‐bis(ethylenediphenylsilyl)benzene]s

1,4‐Bis(vinyldiphenylsilyl)benzene ( I ) has been prepared and copolymerized by Pt‐catalyzed hydrosilylation with 1,9‐dihydridodecamethylpentasiloxane ( II ), 3,5,7‐tris(3′,3′,3′‐trifluoropropyl)‐1,1,3,5,7,9,9‐heptamethylpentasiloxane ( III ) and two different α,ω‐bis(hydrido)polydimethylsiloxanes (PDMS). The monomers and polymers were fully characterized by IR, UV, ¹H, ¹³C, ¹⁹F, and ²⁹Si‐NMR spectroscopy. The starting PDMS polymers and the product copolymers were further characterized by GPC, DSC, and TGA. The polymers showed thermal transitions characteristic to thermoplastic elastomers. The 1,4‐bis(ethyldiphenylsilyl)benzene moieties displayed melting transitions above room temperature while copolymer glass transition temperatures were below room temperature. Fluorescence spectra and quantum efficiencies of I and copolymers have been determined. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4825–4831, 2006     

Synthesis and characterization of alt‐copoly(carbosiloxane)s containing oligodiphenylsiloxane segments

Novel α,ω‐divinyloligodiphenylsiloxanes (1,9‐divinyldecaphenylpentasiloxane, 1,7‐divinyloctaphenyltetrasiloxane, 1,5‐divinylhexaphenyltrisiloxane, and 1,3‐divinyltetraphenyldisiloxane) were prepared and copolymerized by Pt‐catalyzed hydrosilylation with α,ω‐dihydridopentasiloxanes. The molecular weights of the copolymers were measured with gel permeation chromatography, and their thermal properties were characterized with differential scanning calorimetry and thermogravimetric analysis. The polymers had high thermal stability in air and nitrogen. The oligomer and polymer structures were determined with ¹H, ¹³C, ¹⁹F, and ²⁹Si NMR and IR spectrometry. The molecular weights of the oligomers were measured with high‐resolution mass spectrometry. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2155–2163, 2005     

Pt‐catalyzed chemical modification of α,ω‐bis(hydrido)polydimethylsiloxanes and copoly(methylhydridosiloxane/dimethylsiloxane) with vinylheptaphenylcyclotetrasiloxane

Pt‐catalyzed hydrosilylation between vinylheptaphenylcyclotetrasiloxane and a series of α,ω‐bis(hydrido)polydimethylsiloxanes and copoly(methylhydridosiloxane/dimethylsiloxane) was used to prepare chemically modified materials. These modified polymers were characterized by IR, UV, and ¹H, ¹³C, and ²⁹Si NMR spectroscopy and gel permeation chromatography (GPC). The molecular weights, determined by GPC, UV, and NMR end‐group analysis, showed the anticipated increases. The thermal properties of the polymers were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The crystallinity, determined by DSC, was either reduced or completely eliminated for the modified polymers. The thermal stabilities, measured in both air and nitrogen by TGA, were slightly higher than the thermal stability of α,ω‐bis(trimethylsiloxy)polydimethylsiloxane. Significantly increased bulk viscosities were observed for all the modified polymers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3007‐3017, 2005     

Kinetic study of copper(I)‐catalyzed click chemistry step‐growth polymerization

Oligomers and polymers containing triazole units were synthesized by the copper(I)‐catalyzed 1,3‐dipolar cycloaddition step‐growth polymerization of four difunctional azides and alkynes. In a first part, monofunctional benzyl azide was used as a chain terminator for the polyaddition of 1,6‐diazidohexane and α,ω‐bis(O‐propargyl)diethylene glycol, leading to polytriazole oligomers of controlled average degree of polymerization (DP_n = 3–20), to perform kinetic studies on low‐viscosity compounds. The monitoring of the step‐growth click polymerization by ¹H NMR at 25, 45, and 60 °C allowed the determination of the activation energy of this click chemistry promoted polyaddition process, that is, E_a = 45 ± 5 kJ/mol. The influence of the catalyst content (0.1–5 mol % of Cu(PPh₃)₃Br according to azide or alkyne functionalities) was also examined for polymerization kinetics performed at 60 °C. In a second part, four high molar mass polytriazoles were synthesized from stoichiometric combinations of diazide and dialkyne monomers above with p‐xylylene diazide and α,ω‐bis(O‐propargyl)bisphenol A. The resulting polymers were characterized by DSC, TGA, SEC, and ¹H NMR. Solubility and thermal properties of the resulting polytriazoles were discussed based on the monomers chemical structure and thermal analyses. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5506–5517, 2008     

Copolymerization of ethylene with isoprene promoted by titanium complexes containing a tetradentate [OSSO]‐type bis(phenolato) ligand

Copolymerization of ethylene with isoprene (IP) catalyzed by 1,4‐dithabutanediyl‐linked bis(phenolato) titanium complexes 1 and 2 and methylaluminoxane (MAO) produced exclusively ethylene‐IP copolymers with good activity. The copolymer microstructure can be varied by changing the ratio between the monomers in the copolymerization feed, affording copolymers with IP content ～60%. The copolymer microstructure was fully elucidated by ¹³C‐NMR spectroscopy of the copolymers with various IP content revealing a strong tendency to the alternating microstructure. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4200–4206, 2010     

Poly(butylene terephthalate‐co‐5‐tert‐butyl isophthalate) copolyesters: Synthesis,characterization, and properties

A series of poly(butylene terephthalate) copolyesters containing 5‐tert‐butyl isophthalate units up to 50 mol %, as well as the homopolyester entirely made of these units, were prepared by polycondensation from a melt. The microstructure of the copolymers was determined by NMR to be random for the whole range of compositions. The effect exerted by the 5‐tert‐butyl isophthalate units on thermal, tensile, and gas transport properties was evaluated. Both the melting temperature (T_m) and crystallinity were found to decrease steadily with copolymerization, whereas the glass‐transition temperature (T_g) increased and the polyesters became more brittle. Permeability and solubility slightly increased with the content in substituted isophthalic units, whereas the diffusion coefficient remained practically constant. For the homopolyester poly(5‐tert‐butyl isophthalate), all these properties were found to deviate significantly from the general trend displayed by copolyesters, suggesting that a different structure in the solid state is likely adopted in this case. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 92–100, 2005     

Synthesis and thermal characterization of poly(dimethyl bicyclobutane‐1,3‐dicarboxylate) and its copolymers

Dimethyl bicyclobutane‐1,3‐dicarboxylate was synthesized. Its homopolymer (PDBD) containing exclusively cyclobutane rings in its backbone was prepared by free radical polymerization. The copolymers of this bicyclobutane monomer with methyl methacrylate were also prepared. The glass transition temperature of the homopolymer is 159°C, while those of its copolymers are 143 and 121°C with 75/25 and 50/50 of the P(DBD/MMA) composition ratio, respectively. The T_g of PDBD homopolymer is substantially higher than that of commercial PMMA homopolymer despite a lower molecular weight, and is also much higher than that of its monomethyl cyclobutanecarboxylate analogue. These DBD homopolymer and copolymers also show better thermostability than the PMMA homopolymer. The weight‐average molecular weight of homopolymer is 37,000. The polydispersities of these polymers are relatively narrow, with the range of 1.6–1.9. These polymers form clear colorless films resembling PMMA film. The DBD homopolymer film shows a very similar optical cutoff compared to PMMA. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1569–1575, 1999     

Polyaddition of bifunctional 1,3‐benzoxazine and 2‐methylresorcinol

A polyaddition system consisted of a bifunctional N‐n‐propyl benzoxazine and 2‐methylresorcinol ( MR ) that proceeds at ambient temperature has been developed. In this system, the aromatic ring of MR acted as a bifunctional monomer, reacting with a two equivalent amount of benzoxazine moieties via their ring‐opening reaction. The polyaddition gave the corresponding linear polymer bearing phenolic moieties bridged by Mannich‐type linkage in the main chain. The linear polymer had a high glass transition temperature, which was comparable to that of the linear polybenzoxazine synthesized by the ring‐opening polymerization of a monofunctional N‐n‐propyl benzoxazine. The employment of a bifunctional N‐allyl benzoxazine in the polyaddition system resulted in the formation of the corresponding polymer with allyl pendants, which exhibited improved heat resistance due to its thermally induced crosslinking reaction. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3867–3872     

Selectivity in anionic and cationic ring‐opening polymerizations of tetramethyl‐1‐(3′‐trifluoromethylphenyl)‐1‐phenylcyclotrisiloxane and tetramethyl‐1‐[3′,5′‐bis(trifluoromethyl)phenyl]‐1‐phenylcyclotrisiloxane

Anionic and cationic ring‐opening polymerizations of two novel cyclotrisiloxanes, tetramethyl‐1‐(3′‐trifluoromethylphenyl)‐1‐phenylcyclotrisiloxane ( I ) and tetramethyl‐1‐[3′,5′‐bis(trifluoromethyl)phenyl]‐1‐phenylcyclotrisiloxane ( II ), are reported. Anionic ring‐opening polymerization of I or II leads to copolymers with highly regular microstructures. Copolymers obtained by cationic polymerizations of I or II , initiated by triflic acid, have less regular microstructures characteristic of chemoselective polymerization processes. The composition and microstructure of copolymers have been characterized by ¹H and ²⁹Si‐NMR, the molecular weight distributions by GPC, and the thermal properties by DSC and TGA. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5235–5243, 2004     

Synthesis,characterization, and properties of vinyl‐terminated copolysiloxanes containing trifluoropropyl and 4‐trifluoromethylphenyl groups

Novel fluorine containing siloxane monomer, namely, 4‐trifluoromethylphenylmethyl cyclosiloxane ( PF3 ) and mixed cyclosiloxane including both 4‐trifluoromethylphenylmethyl siloxane ( P ) unit and trifluoropropyl siloxane ( F ) unit were successfully synthesized in this study. Furthermore, their series including vinyl‐terminated copolymers with different compositions were synthesized. The microstructures of copolymers were investigated by ¹H NMR, ²⁹Si NMR, ¹⁹F NMR, Fourier transform infrared spectroscopy, and differential scanning calorimetry (DSC). The results of characterizations confirmed that the copolymers exhibited random microstructure. Moreover, the analysis of the result of DSC also revealed that the copolymers had a low glass transition temperature. The thermogravimetric analysis indicated that poly(4‐trifluoromethylphenylmethyl)siloxane ( PPF3 ) exhibited higher thermal stability than conventional fluorosilicones rubber ( FSR ). The dynamic mechanical analysis showed that the damping factors of these copolymers were greater than 0.3 in a wide range of temperature. The mass swelling ratios were less than 5.5% when the samples were immersed in No. 3 jet fuel for a month. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1023–1031     

Synthesis and properties of poly(carbonate‐co‐ester)s obtained by cationic ring‐opening copolymerization of spiroorthocarbonate and ε‐caprolactone

Cationic ring‐opening copolymerization behavior of 1,5,7,11‐tetraoxaspiro[5.5]undecane (SOC1) and ε‐caprolactone (CL), and the thermal behavior of the obtained copolymers are described. When SOC1 and CL were cationically copolymerized under various feed ratios using BF₃OEt₂ as the initiator in CH₂Cl₂ at 25 °C, the corresponding copolymers were obtained in 77–99% yields. The ¹H NMR spectroscopic analysis of the copolymers revealed that the copolymer compositions were almost identical to the feed ratios, and the diad ratios of SOC1–SOC1/SOC1–CL and CL–SOC1/CL–CL are 48.0/52.0 and 54.3/45.7. These observations proved the random structures of the copolymers without containing the long blocks of the homopolymer sequences. Differential scanning calorimetric (DSC) analysis revealed that the melting points and melting entharpies decreased with the increase of the SOC1 unit compositions, suggesting that the copolymers gain flexibility as the SOC1 unit increases. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2937–2942, 2006     

Cationic ring‐opening polymerization of novel 1,3‐dehydroadamantanes with various alkyl substituents: Synthesis of thermally stable poly(1,3‐adamantane)s

Cationic ring‐opening polymerizations of 5‐alkyl‐ or 5,7‐dialkyl‐1,3‐dehydroadamantanes, such as 5‐hexyl‐ ( 4 ), 5‐octyl‐ ( 5 ), 5‐butyl‐7‐isobutyl‐ ( 6 ), 5‐ethyl‐7‐hexyl‐ ( 7 ), and 5‐butyl‐7‐hexyl‐1,3‐dehydroadamantane ( 8 ), were carried out with super Brønsted acids, such as trifluoromethanesulfonic acid or trifluoromethanesulfonimide in CH₂Cl₂ or n‐heptane. The ring‐opening polymerizations of inverted carbon–carbon bonds in 4–8 proceeded to afford corresponding poly(1,3‐adamantane)s in good to quantitative yields. Poly( 4–8 )s possessing alkyl substituents were soluble in 1,2‐dichlorobenzene, although a nonsubstituted poly(1,3‐adamantane) was not soluble in any organic solvent. In particular, poly( 8 ) exhibited the highest molecular weight at around 7500 g mol^?1 and showed excellent solubility in common organic solvents, such as THF, CHCl₃, benzene, and hexane. The resulting poly( 4–8 )s containing adamantane‐1,3‐diyl linkages showed good thermal stability, and 10% weight loss temperatures (T₁₀) were observed over 400 °C. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4111–4124     

Copolymerization of ethylene and cyclopentene with bis(β‐enaminoketonato) titanium complexes

The copolymerizations of ethylene and cyclopentene with bis(β‐enaminoketonato) titanium complexes {[(Ph)NC(R₂)CHC(R₁)O]₂TiCl₂; R₁ = CF₃ and R₂ = CH₃ for 1a , R₁ = Ph and R₂ = CF₃ for 1b ; and R₁ = t‐Bu and R₂ = CF₃ for 1c } activated with modified methylaluminoxane (MMAO) as a cocatalyst were investigated. High‐molecular‐weight copolymers with cis‐1,2‐cyclopentene units were obtained. The catalyst activity, cyclopentene incorporation, polymer molecular weight, and polydispersity could be controlled over a wide range through the variation of the catalyst structure and reaction parameters, such as the Al/Ti molar ratio, cyclopentene feed concentration, and polymerization reaction temperature. The complex 1b /MMAO catalyst system exhibited the characteristics of a quasi‐living ethylene polymerization and an ethylene–cyclopentene copolymerization and allowed the synthesis of polyethylene‐block‐poly(ethylene‐co‐cyclopentene) diblock copolymer. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1681–1689, 2005     

Ring‐Opening and polymerization of 1‐[2′‐(heptaphenylcyclotetrasiloxanyl)ethyl]‐1,3,3,5,5‐pentamethylcyclotrisiloxane

1‐[2′‐(Heptaphenylcyclotetrasiloxanyl)ethyl]‐1,3,3,5,5‐pentamethylcyclotetrasiloxane ( II ) was prepared from 1‐[2′‐(methyldichlorosilyl)ethyl]‐1,3,3,5,5,7,7‐heptaphenylcyclotetrasiloxane ( I ) and tetramethyldisiloxane‐1,3‐diol. Acid‐catalyzed ring‐opening of II in the presence of tetramethyldisiloxane gave 1,9‐dihydrido‐5‐[2′‐(heptaphenylcyclotetrasiloxanyl)ethyl]nonamethylpentasiloxane ( III ) and 1,9‐dihydrido‐3‐[2′‐(heptaphenylcyclotetrasiloxanyl)ethyl]nonamethylpentasiloxane ( IV ). Both acid‐ and base‐catalyzed ring‐opening polymerization of II gives highly viscous, transparent polymers. The structures of I – IV and polymers were determined by UV, IR, ¹H, ¹³C, and ²⁹Si NMR spectroscopy. In addition, molecular weights obtained by GPC and NMR end group analysis were confirmed with mass spectrometry. On the basis of ²⁹Si NMR spectroscopy, the polymers appear to result exclusively from ring‐opening of the cyclotrisiloxane ring. No evidence for ring‐opening of the cyclotetrasiloxane ring was observed. Polymer properties were determined by DSC and TGA. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 137–146, 2006     

Development of amorphous copolyesters based on 1,4‐cyclohexanedimethanol

The modification of poly(ethylene terephthalate) with 1,4‐cyclohexanedimethanol and the modification of poly(1,4‐cyclohexylenedimethylene terephthalate) with ethylene glycol or isophthalic acid retard the crystallization of the copolyester backbone, and over a wide range of comonomer concentrations, very slowly crystallizing, essentially amorphous copolyesters are formed. These amorphous copolyesters possess attractive physical properties such as toughness, low color, and chemical resistance, and since their first commercial introduction in 1977, these copolyesters have become the basis of a large and growing plastics business for Eastman Chemical Co. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5847–5852, 2004     

Synthesis,crystal structure,and spectroscopic and thermal properties of the polymeric compound catena‐poly[[bis(2,4‐dichlorobenzoato)zinc(II)]‐μ‐isonicotinamide]

Zinc(II) carboxylates with O‐, S‐ and N‐donor ligands are interesting for their structural features, as well as for their antibacterial and antifungal activities. The one‐dimensional zinc(II) coordination complex catena‐poly[[bis(2,4‐dichlorobenzoato‐κO)zinc(II)]‐μ‐isonicotinamide‐κ²N¹:O], [Zn(C₇H₃Cl₂O₂)₂(C₆H₆N₂O)]_n, has been prepared and characterized by IR spectroscopy, single‐crystal X‐ray analysis and thermal analysis. The tetrahedral ZnO₃N coordination about the Zn^II cation is built up by the N atom of the pyridine ring, an O atom of the carbonyl group of the isonicotinamide ligand and two O atoms of two dichlorobenzoate ligands. Isonicotinamide serves as a bridge between tetrahedra, with a Zn...Zn distance of 8.8161 (7) Å. Additionally, π–π interactions between the planar benzene rings contribute to the stabilization of the extended structure. The structure is also stabilized by intermolecular hydrogen bonds between the amino and carboxylate groups of the ligands, forming a two‐dimensional network. During thermal decomposition of the complex, isonicotinamide, dichlorobenzene and carbon dioxide were evolved. The final solid product of the thermal decomposition heated up to 1173 K was metallic zinc.     

cis‐1,4‐specific carbocationic polymerization and copolymerization of 1,3‐dienes initiated by (S,S)‐bis(oxazolinylphenyl)amine chromium complexes

Two new chiral (S,S)‐bis(oxazolinylphenyl)amine chromium dichloride complexes have been synthesized and structurally characterized. In combination with 2 equiv. of borate and an excess of AlR₃, such Cr complexes serve as effective cationic initiators in the stereoregular carbocationic polymerization of 1,3‐dienes such as isoprene (IP) and myrcene (MY), affording cyclized cis‐1,4‐PIPs/PMys (cis‐1,4‐selectivity up to 96%) with cyclic sequence contents ranging from 26% to 87%. Moreover, these Cr initiator systems also exhibit an unprecedented control over sequence distribution of comonomers in the carbocationic copolymerization of IP and MY, preparing novel copolymers with different microstructures from mainly cyclized cis‐1,4‐specific statistical copolymers to cyclic olefin copolymers. The nature of Cr complex, borate, AlR₃, temperature, molar ratio of comonomers has considerable effect on the (co)polymer's yield, stereoselectivity, cyclization, and comonomer sequence distribution. A plausible mechanism is suggested, which gives a new strategy for biomimetic synthesis of natural rubber. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 55, 1250–1259     

Vinyl homo/copolymerization of norbornene and ethylene using sterically enhanced 1,2‐bis(arylimino)acenaphthene–palladium precatalysts

A family of unsymmetrical 1,2‐bis(imino)acenaphthene‐palladium methyl chloride complexes [1‐[2,6‐{(C₆H₅)₂CH}₂‐ 4‐{C(CH₃)₃}‐C₆H₂N]‐2‐(ArN)C₂C₁₀H₆]PdMeCl (Ar = 2,6‐Me₂Ph Pd1 , 2,6‐Et₂Ph Pd2 , 2,6‐ⁱPr₂Ph Pd3 , 2,4,6‐Me₃Ph Pd4 , 2,6‐Et₂‐4‐MePh Pd5 ) have been prepared and fully characterized by ¹H/¹³C NMR, FTIR spectroscopies, and elemental analysis. X‐ray diffraction analysis of Pd2 complex revealed a square planar geometry. Upon activation with methylaluminoxane, all the palladium complexes displayed high activities for norbornene (NBE) homo‐polymerization producing insoluble polymer. For the copolymerization of NBE with ethylene, Pd4 complex exhibited good activities with high incorporation of ethylene (up to 59.2–77.4%) and the resultant copolymer showed high molecular weights as maximum as 150.5 kg mol⁻¹. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 922–930