Research articles

Hydrophilic alternating copolymers (P(11EO/MA)_m) of methoxy poly(ethylene glycol) allyl ether (11EO) and maleic anhydride (MA) were prepared via controlled radical polymerization. The MA units in P(11EO/MA)_m were hydrolyzed to prepare pendant carboxylic acid group-containing polymers (P(11EO/MH)_m). Furthermore, an amphiphilic diblock copolymer (P(11EO/MH)_m-PS_n) was prepared via block copolymerization of styrene using P(11EO/MH)_m as a macro-chain transfer agent. The association behavior of P(11EO/MH)_m-PS_n in water was also investigated.

A π-conjugated polymer based on thienylene–vinylene–thienylene (TVT) units can form a thermotropic liquid-crystalline (LC) mesophase over a wide temperature range. Thermal annealing at LC temperatures strongly enhanced hole mobilities in organic field-effect transistors (OFETs) owing to improved molecular ordering. Because of its thermoplasticity, the TVT-based π-conjugated polymer can also be processed into semiconducting fine microfibers and serve as a charge transport pathway in microfiber OFETs.

Active, hydrophilic, piezoelectric PLLA surface is formed by correlating processing parameters with etching and annealing as post-processing steps. Optimal design is obtained after uniaxial drawing of films for five times their length at 90 °C with 40 mm min⁻¹ drawing rate and post-processing heat treatment at 140 °C followed by surface alkaline etching. We designed active PLLA film with high potential for intensive interactions with cells, very important for further biomedical applications, including exploring the effect of piezoelectricity on cell proliferation.

Herein, several synthetic procedures for the synthesis of uniform PEGs were compared. The importance of SEC as analytical method for the determination of the precise structure and purity of uniform PEGs was shown by means of simple symmetry peak analysis, revealing that SEC can detect contaminations of only 2% of oligomers with only one repeat unit difference.

Schwiertz et al. report on the synthesis of miktoarm star polymers based on polypept(o)ides by nucleophilic ring opening polymerization of N-carboxyanhydrides. The reported procedures allow for precise control over chain length, number of arms and end group functionality.

The epoxydized soybean oil grafted with CTBN (ESO-g-CTBN) was synthesized from ring opening reaction between epoxide group and carboxyl group. The ESO-g-CTBN help to improve the fracture toughness of epoxy resin by the mechanism as shown in the figure.

By virtue of “core first” method, ABC star quaterpolymers were controllably synthesized by combination of controlled polymerization and thiolactone chemistry. The miktoarm stars were responsive to temperature, pH, CO₂, O₂ and oxidation, and thus the phase transition temperature, size and morphology of copolymer assemblies could be efficiently tuned via adopting a single stimulus or combined stimuli.

The sulfur-containing styrene derivative, 4-methylenethiochromane (META), was subjected to anionic copolymerization with isoprene (Ip) modified with different additives. The reactivity of META can be effectively regulated with additives; thus, the regulation of the alternating or gradient copolymerization of META and Ip was facilely realized through the use of additives.

An efficient and straightforward strategy for the synthesis of uniform, sequence-defined oligo(ester-amide-ester)s via sequential nucleophilic substitution reactions and Passerini reaction was developed. The side groups could be easily regulated by the Passerini reaction of different aldehydes. The synthesis of uniform, symmetrical, long-chain oligomers was further demonstrated by an iterative approach. The DIC/DPTS-mediated polycondensation of the α,ω-hydroxy carboxylic acids as the sequence-defined oligomer afforded high-molecular-weight periodic poly(ester-amide-ester)s. The thermal properties of these oligo/poly(ester-amide-ester)s were also examined.

Well-defined poly(arylene ether sulfone)-b-polylactides (PES-b-PLAs) were successfully synthesized and their microphase separation behavior was investigated. PES was obtained via chain growth condensation polymerization, and subsequent end group modification followed by ring opening polymerization of d,l-lactide produced the diblock copolymers. By small-angle X-ray scattering experiments in bulk, the formation of ordered morphologies including spherical, cylindrical, gyroidal, and lamellar was observed. An effective interaction parameter at 150 °C was roughly estimated as 0.12 for the first time in engineering plastic-containing block copolymers.

Alkali metal carboxylates, which are readily available and widely used as food additives, were found to promote the ring-opening polymerization (ROP) of trimethylene carbonate (TMC) to produce poly(trimethylene carbonate) (PTMC). The sodium acetate-catalyzed ROP of TMC proceeded in the presence of an alcohol initiator under solvent-free conditions, even at very low catalyst loadings of 0.01–0.0001 mol%. This ROP system enabled the synthesis of PTMCs with predicted molecular weights ranging from 2400 to 11 700 g mol⁻¹ and narrow dispersities (~1.23).

This study describes the production of the amphiphilic bioresorbable polymers sorbitan–PLA and PEG–PLA in a single reactor. This method aims to simplify the separation process and reduce purification costs while increasing the chemical yield. The obtained mixtures could stabilize squalene/water interfaces, resulting in a double-dispersion structure that is favorable for encapsulation in sustained delivery applications.

Based on the mechanism of cellular formation, the cellular formation and postcuring process were separated in this paper. First, the foamed sheets were rested at room temperature for 20 min. Then, the foamed sheets were fully vulcanized in a plate vulcanizing press at 165 °C for 8 min. A novel method of preparing microcellular silicone rubber foams without surface defects has been successfully created.

The polymerization and crystallization of polyamide 6 (PA6) via anionic polymerization was observed using a combination of in situ wide-angle X-ray scattering (WAXS), temperature measurement, and real-time visualization at 119–182 °C. In-situ WAXS discriminated between polymerization and the crystallization of PA6. The WAXS results indicated that polymerization was fast at 139–155 °C, and crystallization was fast at 148–155 °C. The crystallinity of PA6 decreased with increasing temperature. We concluded that molding temperatures between 148 and 155 °C were suitable for high productivities of PA6 with good properties.

Long-chain-branched poly(aryl ether sulfone)-poly(tetrahydrofuran) multiblock copolymers composed of hard linear and soft branching segments were synthesized from bromo-terminated poly(tetrahydrofuran) and hydroxy-terminated poly(aryl ether sulfone). Optimization of the polymerization conditions afforded soluble powder at a reaction concentration of 7 wt%. Microphase-separated morphology was observed for the branched multiblock copolymers. Compared with the corresponding linear multiblock copolymer, the branched polymer chains in the soft domains become less entangled and more reminiscent of hyperbranched architectures, whereas the overall chain entanglements are increased due to the long-chain-branched structure.

This study examines the use of poly(glycidyl methacrylate) (PGMA)-coated polystyrene functionalized with peptides that mimic receptors found on red blood cells for detection of the influenza virus. Although the current method, the hemagglutination inhibition test, utilized by the World Health Organization, is simple, it has some limitations. We found that our peptide dimers attached to beads were efficiently agglutinated, leading us to detect the presence of the influenza virus antigens. We believe that our study makes a significant contribution to the fight against influenza because we provide an alternative method for the important task of influenza surveillance and diagnosis.

We introduce a facile method to convert the bromine end of the polymer into a hydroxyl group. For this, bromine-terminated polystyrene (PS-Br) was prepared by atom transfer radical polymerization. The bromine groups of the PS-Br could be directly converted to hydroxyl groups by using Ag⁺ as the Lewis acid in water/acetone. The conversion yield was investigated by ¹H nuclear magnetic resonance spectroscopy, high-performance liquid chromatography, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Vinylcycloalkanes with 12-, 15-, and 21-membered rings were synthesized from commercially available cycloalkanones or cycloalkyl carboxylic acids derived from malonate and ω-bromo-α-alkenes. Pd complexes with diimine ligands promoted the isomerization polymerization of vinylcycloalkanes with 15- and 21-membered rings to afford polymers having cycloalkylene groups in the main chain. Vinylcycloheneicosane with a 21-membered ring afforded polymers with M_n up to 9700, whereas vinylcycloalkanes with smaller ring sizes (8- and 12-membered rings) yielded oligomers with M_n = 720–1600.

A new nickel diphosphine catalyst was synthesized and evaluated for Suzuki–Miyaura cross-coupling polymerization. The diphosphine is comprised of two electronically and sterically distinct phosphine donors, a PPh₂ group and a PEt₂ group. The catalyst was employed to bring about controlled polymerization of a 3-hexylthiophene monomer to afford poly(3-hexylthiophene). The catalyst was particularly effective for bringing about this polymerization in the presence of excess free ligand. The catalyst resting state was also probed using NMR spectroscopy and an externally initiated catalyst.

The solubility of thermostable alkyl phosphate ester copper complexes in poly(alkyl methacrylate) has been investigated for use as near-infrared-absorbing dyes. 2-Ethylhexyl methacrylate solutions of the 2-ethylhexyl phosphate copper complex and isodecyl phosphate copper complex maintained their transparency even after polymerization, so these two copper complexes show good solubility in poly(2-ethylhexyl methacrylate). Both of the resin plates have visible light transmittance of above 80% and solar direct transmittance of below 50% from spectral transmission. Thus, these resin materials are suitable for window materials that require heat-shielding properties and transparency.