Photopolymerization of biocompatible phosphorus‐containing vinyl esters and vinyl carbamates

Phosphorus‐containing vinyl esters and vinyl carbamates were synthesized as new biocompatible and degradable photopolymers. Reactivity of the monomers with one, two, and three polymerizable double bonds was evaluated by photo‐differential scanning calorimetry. With respect to their potential application in the biomedical field, studies on cytotoxicity, mechanical stability, and hydrolytic erosion behavior of the poly(vinyl alcohol)‐based derivatives were performed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2916–2924, 2010     

Dynamic cross‐links to facilitate recyclable polybutadiene elastomer with excellent toughness and stretchability

A facile cross‐linking strategy of using small molecules as physcial crosslinkers to facilitate recyclable polybutadiene (PB) elastomer with excellent toughness and stretchability is demonstrated. Carboxylic acid groups were incorporated along the PB backbone via thiol‐ene reaction, and then the polymer can be cross‐linked by ionic hydrogen bonds between the carboxylic acid groups from PB and the amine groups of the cross‐linkers. The ionic hydrogen bonds can dynamiclly break and reconstruct upon deformation, thus endowing the resultant polymer with not only high toughness and stretchability (～1800%), but also good self‐recovery and enhanced damping properties. Remarkably, the dynamically cross‐linked PB elastomer can be thermally recycled owing to the thermal reversibility of the ionic hydrogen bonds and the mechanical properties can be largely recovered after reprocessing. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1357‐1366     

Thermal stability of reversible addition–fragmentation chain transfer/macromolecular architecture design by interchange of xanthates chain‐transfer agents

A series of chain‐transfer agents used in reversible addition–fragmentation chain transfer/macromolecular architecture design by interchange of xanthates polymerizations were subjected to thermogravimetric analysis and gas chromatography/mass spectrometry to assess their stability to heat and to determine their degradation pathways. The effects of the chain‐transfer‐agent class and structure on the thermal stability are described. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6980–6987, 2006     

Latex particles bearing hydrophilic grafted hairs with controlled chain length and functionality synthesized by reversible addition–fragmentation chain transfer

A method is described for synthesizing latex particles with anchored hairs by the grafting of hydrophilic chains, synthesized by reversible addition–fragmentation chain transfer, onto functionalized latex particles. These have the potential to bind biologically active species. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1188–1195, 2003     

Coordination Bonds and Diels–Alder Bonds Dual Crosslinked Polymer Networks of Self‐healing Polyurethane

A dual crosslinked self‐healing polyurethane was prepared with robust mechanical properties through the dynamic reversible pyridine‐Fe³⁺ coordination bonds and Diels–Alder (DA) covalent bonds dual crosslinking strategy. Moreover, the mechanical properties and self‐healing ability of polyurethane can be tuned readily by different ratio of the coordination bonds and DA bonds. Under external load, the coordination bonds serve as sacrificial bonds are broken to dissipate energy, the DA bonds can keep the shape of sample. With the coordination bonds participation, the damaged samples can be healed under moderate heating treatment or with the aid of FeCl₃ solution. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2228–2234     

Crosslinked colloids with cyclopropenium cations

Chemical crosslinkers are commonly used to stabilize both natural and synthetic macromolecules, while providing opportunities to install functionality and modulate polymer architecture. Here, we introduce the aromatic cyclopropenium cation as a tri-functional crosslinker of secondary amine-containing polymers. The one-step crosslinking reaction is rapid and requires no subsequent purification. When dispersed in aqueous media, the crosslinked polymers form spherical nanoparticles with highly positive charge that is maintained even in alkaline conditions. This synthetic strategy will enable the incorporation of cyclopropenium into a wide variety of macromolecules. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2641–2645     

Characterization of well‐defined poly(ethylene glycol) hydrogels prepared by thiol‐ene chemistry

Considering the large number of applications for hydrogels, a better understanding of the relation between molecular structure and mechanical properties for well‐defined hydrogel is essential. A new library has been compiled of poly(ethylene glycol) polymers (PEG) of different length end functionalized with diallyl, dithiol, and dimethacrylate, and crosslinked with complementary trifunctional crosslinkers. In this study, the hydrogels were initially analyzed by FT‐Raman and NMR to study the conversion ratio of the functional groups. The effects of solvent type, solid content concentration, curing time and length of the PEG chains on the final leaching, swelling and tensile properties of the hydrogels were studied. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis of well‐defined hairy polymer microspheres by precipitation polymerization and surface‐initiated atom transfer radical polymerization

A variety of polymer microspheres were successfully synthesized by the surface‐initiated atom transfer radical polymerization (SI‐ATRP) of monomers by using monodisperse polymer microsphere having benzyl halide moiety as a multifunctional polymeric initiator. First, a series of monodisperse polymer microsphere having benzyl chloride with variable monomer ratio (P(St‐DVB‐VBC)) were synthesized by the precipitation polymerization of styrene (St), divinylbenzene (DVB), and 4‐vinylbenzyl chloride (VBC). Next, hairy polymer microspheres were synthesized by the surface‐initiated ATRP of various monomers with P(St‐DVB‐VBC) microsphere as a multifunctional polymeric initiator. The hair length determined by the SEC analysis of free polymer was increased with the increase of M/I. These hairy polymer microspheres were characterized by SEM, FT‐IR, and Cl content measurements. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1296–1304     

Full control of polymer properties during the two‐stage on‐demand free‐radical photopolymerization of fiber‐reinforced polymers

The effect of a two‐step free‐radical photopolymerization of an acrylate resin on the polymer properties in the presence of glass fibers is studied. It is found that a first irradiation leading to a partial conversion is effective for the fabrication of a preimpregnated glass‐fiber composite, which can be further processed and fully polymerized through a second irradiation. DMA analysis evidences the formation of a first relatively soft polymer embedding unreacted double bonds during the preirradiation. Further process allows the completion of the photopolymerization together with a reinforcement of the polymer network. This obviously affects the final mechanical properties of the photocomposite. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1440–1447     

Conformational analysis of dipeptide‐derived polyisocyanides

The conformational properties of polymers derived from isocyanodipeptides have been investigated with a combination of model calculations, X‐ray diffraction, and circular dichroism spectroscopy. Depending on the configuration of the side chains, defined arrays of hydrogen bonds along the polymeric backbone are formed. This leads to a well‐defined conformation as, for example, expressed in the formation of lyotropic liquid‐crystalline phases and increased helical stability. Upon the disruption of the hydrogen bonds by a strong acid, a less well‐defined macromolecular conformation is observed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1725–1736, 2003     

Exploiting catalytic chain transfer polymerization for the synthesis of carboxylated latexes via sulfur‐free RAFT

We present a systematic study of incorporating carboxyl groups into latex particles to enhance colloidal stability and the physical properties of the latex. Statistical copolymers of methacrylic acid and methyl methacrylate) were synthesized via catalytic chain transfer polymerization (CCTP) in emulsion. The vinyl‐terminated oligomers were in turn successfully utilized as chain transfer agents for the formation of diblock and pseudo triblock copolymers via sulfur‐free reversible addition–fragmentation chain transfer polymerization (SF‐RAFT). These copolymers were characterized using ¹H NMR, size exclusion chromatography (SEC), dynamic light scattering (DLS), dynamic mechanical analysis (DMA), contact angle measurements and matrix‐assisted laser desorption/ionization time of flight mass spectroscopy (MALDI‐TOF‐MS) techniques. © 2019 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, E1–E9     

Role of minority structures and mechanism of peroxide crosslinking of polyethylene

Minority structures are considered to be defect structures that are formed during polyethylene (PE) preparation and during the crosslinking process in PE. The minority structures that play the predominant role in PE crosslinking are vinyl double bonds. Moreover, the decomposition of dicumyl peroxide in PE does not proceed according to first-order kinetics, but induced peroxide decomposition also takes part. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 675–688, 2004     

Optimizing the monomer structure of polyhedral oligomeric silsesquioxane for ion transport in hybrid organic–inorganic block copolymers

Poly(ethylene oxide)-b-polyhedral oligomeric silsesquioxane (PEO–POSS) mixed with lithium bis(trifluoromethanesulfonyl)imide salt is a nanostructured hybrid organic–inorganic block copolymer electrolyte that may enable lithium metal batteries. The synthesis and characteristics of three PEO–POSS block copolymer electrolytes which only differ by their POSS silica cage substituents (ethyl, isobutyl, and isooctyl) is reported. Changing the POSS monomer structure results in differences in both thermodynamics and ion transport. All three neat polymers exhibit lamellar morphologies. Adding salt results in the formation of a disordered window which closes and gives way to lamellae at higher salt concentrations. The width of disordered window decreases with increasing length of the POSS alkyl chain substituent from ethyl to isobutyl and is absent in the isooctyl sample. Rheological measurements demonstrate good mechanical rigidity when compared with similar all-organic block copolymers. While salt diffusion coefficient and current ratio are unaffected by substituent length, ionic conductivity increases as the length of the alkyl chain substituent decreases: the ethyl substituent is optimal for ion transport. This is surprising because conventional wisdom suggests that ion transport occurs primarily in the PEO-rich domains, that is, ion transport should be unaffected by substituent length after accounting for the minor change in conducting phase volume fraction. © 2020 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2020 © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 363–371     

Synthesis and properties of polyhydroxyurethane bearing silicone backbone

Polyhydroxyurethane bearing silicone backbone was prepared by polyaddition of silicone diamines with a bifunctional five‐membered cyclic carbonate prepared from the corresponding diepoxide and CO₂. Polymerization in propylene glycol methyl ether acetate proceeded smoothly, and polymers could be obtained in high yields under appropriate conditions. The introduced silicone moieties improved the hydrophobicity and lowered the glass transition temperature keeping thermal stability. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1113–1118     

Photomediated crosslinking of cinnamated PDMS for in situ direct photopatterning

Polydimethylsiloxane (PDMS) polymers incorporating pendant cinnamate groups have been synthesized and evaluated for their ability to form patterned thin films via photo‐crosslinking. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3482–3487, 2008     

Study on Post-Polymerization Modification of Ring-Opening Metathesis Polymers Involving Pendant Thiolactone Units

Two different oxanorbornene monomers were prepared and copolymerized with butyl-functionalized oxanorbornene monomer through the ring-opening metathesis polymerization. The resulting polymers were then subjected to the aminolysis reactions with propylamine (PA) in the presence of methyl acrylate (MA) to capture, in situ, the latent thiol. It was found that the polymer, in which the thiolactone unit is close to the polymer backbone, did not undergo an efficient aminolysis reaction even an excess amount of PA was utilized, while the other polymer, in which the thiolactone unit away from the polymer backbone, did efficiently undergo aminolysis reaction even PA was used in low amounts. Besides, a variety of primary amine compounds along with MA were reacted with the polymer, in which the thiolactone group away from the polymer backbone, to test their reactivity toward the aminolysis reactions. All modified polymers were characterized by using conventional instruments such as gel permeation chromatography, nuclear magnetic resonance, and differential scanning calorimetry. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2145–2153     

A solid homogeneous zirconocene catalyst from Cp2ZrCl2 supported on porous polymer particles

Monodisperse cyano‐functionalized porous polymeric beads were synthesized by seeded polymerization; these microparticles were further used as support for zirconocene catalyst, which performed as a solid homogeneous catalyst in ethylene polymerization. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis of well‐defined copolymer of acrylonitrile and maleic anhydride via RAFT polymerization

Well‐defined copolymer of acrylonitrile (AN) and maleic anhydride (MAn) has been successfully synthesized via reversible addition‐fragmentation chain transfer polymerization. The polymerization kinetics and “living”/controlled features were thoroughly studied and confirmed. The thermal properties and spinnability of the prepared copolymers were investigated via differential scanning calorimetry, thermogravimetric analyzer, and electrospinning subsequently. When PAN‐co‐PMAn was used as precursors, nonwoven with “crosslinked” structures was obtained during electrospinning. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5263–5269     

Synthesis and characterization of well‐defined lactic acid–PEG cooligomers and its tricarbonyl rhenium conjugates

This article describes the synthesis and characterization of hydroxyl tailored, molecularly defined biodegradable cooligomers capable of chelating rhenium for potential radiopharmaceuticals. New insights were gained during the synthesis of lactide based on dimethylaminopyridine‐catalyzed transesterification. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Healable dual organic–inorganic crosslinked sol–gel based polymers: Crosslinking density and tetrasulfide content effect

In this article, the first generation of healable sol–gel based polymers is reported. A dual organic–inorganic crosslinked network is developed containing non‐reversible crosslinks and reversible (tetrasulfide) groups. The designed polymer architecture allows thermally induced mesoscale flow leading to damage closure followed by interfacial strength restoration due to reformation of the reversible groups. While the reversible bonds are responsible for the flow and the interface restoration, the irreversible crosslinks control the required mechanical integrity during the healing process. The temperature dependent gap closure kinetics is strongly affected by the crosslinking density and tetrasulfide content. Raman spectroscopy is used to explain the gap closure kinetics in air and dry nitrogen. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1953–1961