Synthesis of refractive star‐shaped polysulfide by anionic polymerization of phenoxy propylene sulfide using an initiating system consisting of trifunctional thiol derived from five‐membered cyclic dithiocarbonate and amine

Star‐shaped poly(phenoxy propylene sulfide) [poly (PPS)] were synthesized by anionic polymerization using a trifunctional initiator ( I ₁) derived from a trifunctional five‐membered cyclic dithiocarbonate and benzyl amine. Conditions for the anionic polymerization of PPS were optimized to obtain polymers with desired M_ns and narrow M_w/M_ns. The best catalyst and solvent were DBU and DMF, respectively. The star‐shaped structure of the resulting star poly(PPS) was supported by SEC analysis. The refractive indexes (n_D) of the star poly (PPS) were relatively high (>1.64). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 525–531, 2010     

Controlling the thermomechanical properties of biobased ABA triblock copolymers comprising polylactide (A) and poly(1,2-propylene succinate) (B) with high molecular weight

Bis-hydroxyl-terminated poly(1,2-propylene succinate) (PPS-diols) with high molecular weight (10–40 kDa) are prepared by two-step melt polycondensation of succinic acid and 1,2-propanediol with Ti(BuO)₄ as the catalyst. By using these PPS-diols as macroinitiators, the ring-opening polymerization of d - and l -lactides is readily conducted to obtain enantiomeric ABA triblock copolymers consisting of poly(l -lactide) and PPS (B) (t-l -PPS) as well as those of poly(d -lactide) and PPS (B) (t-d -PPS) which have higher PPS compositions (20–70 wt%) in addition to high molecular weight (20–80 kD). The T_g, T_m, and ΔH_m values of the t-l -PPS copolymers as well as the stereo mixtures of t-l -PPS/t-d -PPS are controlled to linearly decrease with increasing the PPS content. The copolymers also exhibit higher elastomeric properties with increasing the PPS content. The tensile properties of the copolymer films having higher PPS contents (both the single block copolymers and stereo mixtures) are comparable to those of the oil-based thermoplastic elastomers. It is therefore concluded that these block copolymers can afford thermoplastic elastomers or flexible plastic materials having a 100% biobased content.     

Synthesis and mechanochemical properties of biobased ABCBA-type pentablock copolymers comprising poly-d-lactide (A), poly-l-lactide (B) and poly(1,2-propylene succinate) (C)

The ABCBA pentablock copolymers (p-d -l -PPS) comprising poly(d -lactide) (PDLA: A), poly(l -lactide) (PLLA: B) and poly(propylene succinate) (PPS: C) were successfully synthesized by two-step ring-opening polymerization (ROP) of d - and l -lactide using a dihydroxy-terminated PPS as a macro-initiator. The pentablock copolymers revealed the high stereocomplex (sc) crystallinity, thermal stability and elastomeric property in their solution-cast films. It was found that the T_g was found to be proportional to the PPS content, whereas the T_m was proportional to their average block length. The thermal resistivity of the copolymer films was found to be as high as 202°C owing to their sc formation. The copolymers also showed improved stereocomplexibility compared to the enantiomeric mixtures of triblock copolymers (PLLA-PPS-PLLA and PDLA-PPS-PDLA) having similar PLLA and PDLA chain lengths. These pentablock copolymers can afford thermoplastic elastomers or flexible plastic materials having a 100% bio-based content, showing high heat-resistive property.     

New synthesis of polyaromatics through oxidative polymerization by using metal complexes with air

The oxidative polymerization provides a new synthetic route to polyaromatics. Poly(p-phenylene sulfide) (PPS) is produced by oxidative polymerization of thiophenol with a vanadyl complex catalyst. The metal complexes act as an efficient catalyst of oxygen oxidative polymerization. The polymerization to yield PPS is discussed especially focusing on the catalytic mechanism of the complexes.     

Phase separation in semicrystalline blends of poly(phenylene sulfide) and poly(ethylene terephthalate). II. Effect of poly(phenylene sulfide) homopolymer solubilization of PPS‐graft‐PET copolymer on morphology and crystallization behavior

The morphology and crystallization behavior of poly(phenylene sulfide) (PPS) and poly(ethylene terephthalate) (PET) blends compatibilized with graft copolymers were investigated. PPS‐blend‐PET compositions were prepared in which the viscosity of the PPS phase was varied to assess the morphological implications. The dispersed‐phase particle size was influenced by the combined effects of the ratio of dispersed‐phase viscosity to continuous‐phase viscosity and reduced interfacial tension due to the addition of PPS‐graft‐PET copolymers to the blends. In the absence of graft copolymer, the finest dispersion of PET in a continuous phase of PPS was achieved when the viscosity ratio between blend components was nearly equal. As expected, PET particle sizes increased as the viscosity ratio diverged from unity. When graft copolymers were added to the blends, fine dispersions of PET were achieved despite large differences in the viscosities of PPS and PET homopolymers. The interfacial activity of the PPS‐graft‐PET copolymer appeared to be related to the molecular weight ratio of the PPS homopolymer to the PPS segment of the graft copolymer (M_H/M_A). With increasing solubilization of the PPS graft copolymer segment by the PPS homopolymer, the particle size of the PET dispersed phase decreased. In crystallization studies, the presence of the PPS phase increased the crystallization temperature of PET. The magnitude of the increase in the PET crystallization temperature coincided with the viscosity ratio and extent of the PPS homopolymer solubilization in the graft copolymer. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 599–610, 2000     

Synthesis of well‐defined and end‐polymerizable star‐shaped polysulfides and their application to negative photoresist

Various star‐shaped poly(phenoxy propylene sulfide)s (PPSs) bearing curable end groups were synthesized by the functionalization of the propagating ends of star‐shaped poly(PPS) with various electrophilies. The functionalization with chloromethyl styrene proceeded quantitatively, and afforded polymers with M_n almost agreed with theoretical value and narrow M_w/M_n. The photocuring conditions were optimized, and the addition of 10 wt % of poly(ethylene glycol) diacrylate was effective to attain sufficient crosslinking. The photocuring reaction of the end‐functionalized poly(PPS) films cast on silicon wafers was conducted by UV irradiation. The cured poly (PPS)s became insoluble in THF, supporting the sufficient crosslinking. Developing of a cured polymer yielded a negative photoresist pattern. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis of cyclic polysulfides: Controlled ring‐expansion polymerization of cyclic tetrathioester with thiirane

We synthesized cyclic tetrathioesters containing thioester moieties at the o‐position (o‐CTE) and m‐position (m‐CTE) of an aromatic skeleton. The reaction of phenoxy propylenesulfide (PPS) with o‐CTE and m‐CTE was examined using tetrabutylammonium chloride as a catalyst in 1‐methyl‐2‐pyrrolidinone, yielding the corresponding cyclic polysulfides poly[o‐CTE(PPS)_n] with M_n's = 37,000–54,000 at 34–61% yields and poly[m‐CTE(PPS)_n] with M_n's = 46,600–107,200 at 63–>99% yields. Although the molecular weights of poly[o‐CTE(PPS)_n] could not be controlled, those of poly[m‐CTE(PPS)_n] could be controlled by the feed ratios of PPS and reaction temperature. Furthermore, the glass transition temperature (T_g) and thermal decomposition temperature (T_dⁱ) of poly[m‐CTE(PPS)_n] increased with decreasing molecular weights. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 857–866     

Synthesis and kinetic modeling of biomass‐derived renewable polyesters

The biomass‐derived polyesters poly(1,3‐propylene 2,5‐furandicarboxylate) (PPF), poly(1,3‐propylene succinate) (PPS) and poly(1,3‐propylene 2,5‐furandicarboxylate‐co‐1,3‐propylene succinate) (PPFPS) have been synthesized via a two‐step process involving polycondensation and azeotropic distillation. The kinetic parameters were obtained by fitting the experimental data from a batch polymerization reactor to three different kinetic models for polyesterification reactions. The activation energies of the all monomer systems were obtained by Arrhenius plots. Given the increasing availability of biomass‐derived monomers their use in renewable polyesters as substitutes for fossil fuel derived chemicals becomes a distinct possibility. The kinetic modeling of the uncatalyzed polyesterification reactions will enable further integrative process simulation of the studied bioderived polymers and provide a reference for future practical study or industrial applications of catalyzed polyesterification reactions and other bioderived monomer systems. © 2016 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2876–2887     

原位聚合MnO_2/PoPD@PPS复合滤料及其NH_3-SCR脱硝性能研究

在聚苯硫醚(PPS)滤料表面包覆一层二氧化锰/聚邻苯二胺(PoPD)复合物。利用π-π共轭效应,将邻苯二胺(OPD)单体均匀吸附在PPS纤维表面,然后通过高锰酸钾溶液使邻苯二胺氧化聚合,在纤维表面原位生成聚邻苯二胺包覆层,同时高锰酸钾被还原成MnO_2催化剂,插入到聚邻苯二胺基体中。通过原位聚合生成的MnO_2/PoPD复合物与PPS滤料间有很强的黏结性,使得催化剂和滤料能牢固地结合在一起。该复合滤料制备方法简单,实验条件温和,对滤料本身性能没有损伤,通过FESEM、XPS、XRD、FT-IR、脱硝活性测试等对其结构和性能进行了研究。脱硝测试结果表明,KMnO4/PPS质量比为1∶1时,复合滤料在80-180℃下脱硝率可达36%-94%,10 h的催化剂稳定性测试中,其脱硝率在160℃下仍保持在88%;Mn 2p的XPS谱图证实复合滤料上催化剂为MnO_2;复合滤料的XRD谱图表明MnO_2为非晶结构;从FESEM照片可以看出,MnO_2催化剂在PPS滤料上分散均匀。     

Poly(propylene isophthalate), poly(propylene succinate), and their random copolymers: Synthesis and thermal properties

Poly(propylene isophthalate) (PPI), poly(propylene succinate) (PPS), and poly(propylene isophthalate/succinate) (PPI‐PPS) random copolymers were synthesized and characterized in terms of chemical structure and molecular weight. The thermal behavior was examined by TGA and DSC. All the polymers showed a good thermal stability. At room temperature, they appeared as semicrystalline materials, except 20PPI‐PPS and 30PPI‐PPS: the main effect of copolymerization was a lowering in the amount of crystallinity and a decrease of T_m with respect to homopolymers. A crystalline phase of PPI and PPS was evidenced at high content of PI or PS units, respectively. Amorphous samples were obtained after melt quenching and an increment of T_g, with the increment of PI units, was observed. This behavior was explained as due to the presence of stiff phenylene groups. The Wood equation described well T_g‐composition data. Lastly, the presence of a rigid‐amorphous phase was evidenced in copolymers, differently from the two homopolymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 310–321, 2007.     

Synthesis of poly(thio-1,4-phenylene) by oxidative coupling reaction of diphenyl disulfide with potassium persulfate in strongly acidic solutions

The synthesis of poly(thio- 1,4-phenylene) (PPS) at room temperature by the reaction of diphenyl disulfide with potassium persulfate (K₂S₂O₈) in non-basic solvents, in the presence of trifluoromethanesulfonic acid, is reported. The reaction in chlorinated solvents, such as dichloromethane and tetrachloroethane, resulted in partial oxidation of sulfide to sulfoxide and sulfone. On the other hand, the polymerization proceeded well in nitrobenzene and the PPS formed was free of branches, crosslinks and thianthrene units. The molecular weight of the polymers formed in different solvents were in the range 2000–8000. The reaction proceeded under identical conditions with bis(2,6-dimethylphenyl) disulfide as well, but the polymer yield was lower.     

结晶／结晶共混体系聚苯硫酸／聚醚醚酮中聚醚醚酮组分的结晶熔融行为──熔融温度的影响

igh performance crystal/crystal blends of poly (phenylene sulfide) and poly (ether ether ketone) (PPS/PEEK) have ho prepared by dry mixing and melhng at different temperatures. The crystallization and melting behavior of PEEK component in quenched blends have ho investigated by differential scanningcalorimetry (DSC). As melt temperature (T_melt) increases, the crystalline andmelting behavior of PPS and PEEK is different due to the difference of thermalproperty of PPS and PEEK. The temperature of melhng (T_m) and crystallization (T_c) and crystallinity (X_c) of PEEK component in blends increase as the content of PPS increases up to 50%. However. this action of PPS is suppresed with increasing of T_melt.     

Block copolymers of telechelic poly(phenylene sulfide) and semiaromatic thermotropic liquid crystalline polyester segments

We report the synthesis and characterization of copolymers comprising poly(phenyl sulfide) (PPS) blocks and semiaromatic thermotropic liquid crystalline polymer (TLCP) blocks. The copolymers, synthesized by melt-transesterification of dicarboxy-terminated poly(phenylene sulfide) with poly(ethylene terephthalate-co-oxybenzoate) (PET/OB), were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized light optical microscopy (PLOM). The crystallizability and liquid crystalline properties of the copolymers are greatly influenced by the extent of interchange reactions, the mole percent of oxybenzoate with respect to the PET, the PPS : PET/OB weight ratio, and the reaction time. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2707–2713, 1998     

High‐molecular‐weight poly(1,2‐propylene succinate): A soft biobased polyester applicable as an effective modifier of poly(l‐Lactide)

Poly(1,2‐propylene succinate) (PPS) having high molecular weight can be synthesized by multi‐step melt‐polycondensation of succinic acid (SA) and 1,2‐propylene glycol (PG) with various catalysts. The first step is noncatalytic esterification/oligomerization of the two monomers, followed by the second step of catalytic melt‐polycondensation. In this step, co‐catalyst systems of Zn(AcO)₂/Ge(OBu)₄ and Zn(AcO)₂/Ti(BuO)₄ are effective for obtaining PPS having middle molecular weights (>10.0 kDa). This middle‐molecular‐weight PPS is chain‐elongated in the third‐step polycondensation with Zn(AcO)₂ as the catalyst to obtain a molecular weight reaching 120 kDa. As verified by ¹H‐ and ¹³C‐NMR spectra combined with two‐dimensional experiments, PPS has a ω‐bis‐hydroxy structure where the PG units leave the secondary hydroxyl terminals in larger ratio than the primary hydroxyl terminals. The PPS polymers are amorphous in nature, showing T_g around −4 °C. PPS can be solution‐ and melt‐blended with poly(l ‐lactide) (PLLA). By melt‐blending a high‐molecular‐weight PPS in an amount of 7.5–15 wt %, the modulus of the PLLA films decreases below 2000 MPa and the tear strength increases twice, supporting the effectiveness of PPS polymer in imparting flexible nature to PLLA. PPS polymers can therefore be applicable as elastomeric or flexible plastic modifiers having a 100 % biobased content. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1795–1805     

Polymerization of N-(2,3,4,5,6-pentafluorophenyl)-maleimide

A novel fluorine-containing polymer, poly[N-(2,3,4,5,6-pentafluorophenyl)maleimide], was prepared by the anionic polymerization of N-(2,3,4,5,6-pentafluorophenyl)maleimide (PFPMI). Anionic polymerization with alkali metal tert-butoxides gave poly(PFPMI) in 14–32% yield. Phenyllithium and sec-butyllithium also afforded poly(PFPMI). No polymer was obtained with a radical initiator such as 2,2′-azoisobutyronitrile. The polymerization took place only via the vinylene group of PFPMI and no appreciable side-reaction occurred. The obtained poly(PFPMI) shows unimodal molecular weight distribution and begins to decompose at 325°C.     

Synthesis of poly(p‐phenylene sulfide) from bis(4‐bromophenyl) disulfide

Improved reaction conditions for the preparation of poly(p‐phenylene sulfide) (PPS) directly from bis(4‐bromophenyl) disulfide (BBD) have been established. Heating BBD with magnesium metal afforded only a low molecular weight polymer. PPS with a melting temperature around 280 °C was obtained from BBD in the presence of sodium carbonate or zinc metal. The best results were obtained with the addition of a catalytic amount of KI to the zinc–BBD mixture. Polymers prepared by the above methods are semicrystalline and dissolve in 1‐chloronaphthalene and have properties comparable to commercial PPS. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 900–904, 2006     

Oxygen‐Triggered Switchable Polymerization for the One‐Pot Synthesis of CO2‐Based Block Copolymers from Monomer Mixtures

Switchable polymerization provides the opportunity to regulate polymer sequence and structure in a one‐pot process from mixtures of monomers. Herein we report the use of O₂ as an external stimulus to switch the polymerization mechanism from the radical polymerization of vinyl monomers mediated by (Salen)Co^III?R [Salen=N,N′‐bis(3,5‐di‐tert‐butylsalicylidene)‐1,2‐cyclohexanediamine; R=alkyl] to the ring‐opening copolymerization (ROCOP) of CO₂/epoxides. Critical to this process is unprecedented monooxygen insertion into the Co?C bond, as rationalized by DFT calculations, leading to the formation of (Salen)Co^III?O?R as an active species to initiate ROCOP. Diblock poly(vinyl acetate)‐b‐polycarbonate could be obtained by ROCOP of CO₂/epoxides with preactivation of (Salen)Co end‐capped poly(vinyl acetate). Furthermore, a poly(vinyl acetate)‐b‐poly(methyl acrylate)‐b‐polycarbonate triblock copolymer was successfully synthesized by a (Salen)cobalt‐mediated sequential polymerization with an O₂‐triggered switch in a one‐pot process.     

Anionic dispersion polymerization. I. control of particle size

Studies on the mechanism for the formation of the stable dispersion polystyrene prepared by anionic dispersion polymerization of styrene in n-hexane using poly(t-butylstyrene) as the stabilizing moiety in steric stabilizer have been performed by a combination of size exclusion chromatographic (SEC) and transmission electron microscopic (TEM) analyses. When the molecular weight of poly(t-butylstyrene) as the stabilizing moiety exceeded 1.76 X 10⁴ g/mol, the formed polymer particles successfully retained a steric stability. Block copolymerization of t-butylstyrene and styrene in n-hexane has also provided the dispersion polymer particles with a relatively narrow size distribution. The stable dispersion polystyrenes have been produced in n-hexane by polymerization of styrene using the mixture of sec-butyllithium and poly(t-butylstyryl)lithium. The polymerization is called living dispersion polymerization (LDP), in which poly(t-butylstyrene-b-styrene) as the steric stabilizer and polystyrene can be formed simultaneously. The particle size was readily controlled by a combination of the concentration of monomer and the molar ratio of poly(t-butylstyryl)lithium to sec-butyllithium, for instance, [stabilizing moiety]/[RLi]. © 1996 John Wiley & Sons, Inc.     

Cyclopolycondensation. XIII. New synthetic route to fully aromatic poly(heterocyclic imides) with alternating repeating units

Fully aromatic poly(heterocyclic imides) of high molecular weight were prepared by the cyclopolycondensation reactions of aromatic diamines with new monomer adducts prepared by condensing orthodisubstituted aromatic diamines with chloroformyl phthalic anhydrides. The low-temperature solution polymerization techniques yielded tractable poly(amic acid), which was converted to poly(heterocyclic imides) by heat treatment to effect cyclodehydration at 250–400°C under reduced pressure. In this way, the polyaromatic imideheterocycles such as poly(benzoxazinone imides), poly(benzoxazole imides), poly(benzimidazole imides) and poly(benzothiazole imides) were prepared, which have excellent processability and thermal stability both in nitrogen and in air. The poly(amic acids) are soluble in such organic polar solvents as N,N-dimethyl-acetamide, N-methylpyrrolidone, and dimethyl sulfoxide, and the films can be cast from the polymer solution of poly(amic acids) (η_inh = 0.8–1.8). The film is made tough by being heated in nitrogen or under reduced pressure to effect cyclodehydration at 300–400°C. The polymerization was carried out by first isolating the monomer adducts, followed by polymerization with aromatic diamines. On subsequently being heated, the open-chain precursor, poly(amic acid), undergoes cyclodehydration along the polymer chain, giving the thermally stable ordered copolymers of the corresponding heterocyclic imide structure.     

Preparation of Well‐Defined Diblock Copolymers with Short Polypeptide Segments by Polymerization of N‐Carboxy Anhydrides

Summary: The ring‐opening polymerization of N‐carboxy anhydrides (NCA) of γ‐benzyl‐L ‐glutamate and β‐benzyl‐L ‐aspartate was studied in the presence of an ammonium chloride‐functionalized poly(ethylene oxide) macroinitiator, which possibly prevents side reactions such as NCA deprotonation. Although polymerization initiated by such macroinitiators was found to be quite slow, well‐defined conjugates of poly(ethylene oxide)‐block‐poly(γ‐benzyl‐L ‐glutamate) and poly(ethylene oxide)‐block‐poly(β‐benzyl‐L ‐aspartate) with polydispersity indexes as low as 1.05 were prepared. Moreover, the presence of ammonium chloride chain ends significantly prevented end‐group cyclization of poly(γ‐benzyl‐L ‐glutamate) after polymerization.

Gel permeation chromatograms recorded for the diblock copolymers of poly(ethylene oxide)‐block‐poly(γ‐benzyl‐L ‐glutamate) prepared by N‐carboxy anhydride polymerization initiated either by PEO‐NH₂ macroinitiator or PEO‐NHequation/tex2gif-stack-1.gifCl⁻ macroinitiator.