Highly Efficient Incorporation of Functional Groups into Aromatic Main-Chain Polymer Using Iridium-Catalyzed C−H Activation and Suzuki−Miyaura Reaction

Highly Efficient Incorporation of Functional Groups into Aromatic Main-Chain Polymer Using Iridium-Catalyzed C−H Activation and Suzuki−Miyaura Reactio

Renewable Polyurethane Microcapsules with Isosorbide Derivatives for Self-Healing Anticorrosion Coatings

Renewable polyurethane microcapsules containing isosorbide derivatives for self-repairing anticorrosion coatings were easily manufactured by interfacial polymerization of a dimer ester–diisocyanate (DE–TDI) prepolymer derived from waste vegetable oil and 1,4-butanediol (BD) as a chain extender using ultrasonication. Two kinds of corrosion inhibitors were also synthesized by the ring-opening reaction of succinic anhydride (SA) or maleic anhydride (MA). Microcapsules having 11–38 μm in diameter were obtained, and the typical core content of microcapsules was around 40–45 wt %. Salt spray tests used for evaluating self-healing anticorrosion coating systems showed significant rust retardancy, depending on the content of the isosorbide derivatives for corrosion control

Preparation and Characterization of a Renewable Pressure-Sensitive Adhesive System Derived from ε‑Decalactone, l‑Lactide, Epoxidized Soybean Oil, and Rosin Ester

Pressure-sensitive adhesives (PSAs) are prepared with plant-based thermoplastic polyester elastomers (TPPEs), rosin ester tackifier, and epoxidized soybean oil plasticizer. Controlled bulk ring-opening transesterification polymerization of ε-decalactone and l-lactide using diethylene glycol as an initiator gives ABA type block polyesters via a one-pot, two-step process with only tin­(II) ethylhexanoate. Three semicrystalline poly­(l-lactide)–poly­(ε-decalactone)–poly­(l-lactide) (PLLA–PDL–PLLA) triblock copolymers are prepared containing 100 kg mol^–1 PDL midblocks and 8–30 wt % PLLA end blocks with narrow dispersities. The mechanical behavior of the triblock architectures is investigated by tensile experiments. The triblocks are combined with the tackifier of 50 wt % and the plasticizer of 15–30 wt %. The thermal, viscoelastic, and morphological properties of the elastomers and the adhesive formulations are determined with differential scanning calorimetry, thermal gravimetric analysis, dynamic mechanical analysis, and atomic force microscopy. The renewable self-adhesive performance is evaluated showing peel strength of 1.9–2.6 N cm^–1, probe tack of 2.2–3.0 N, and static shear strength of >20 000 min comparable to current thermoplastic elastomers and PSAs. These novel materials could hold promise for sustainability and high adhesive performance

Thermoplastic Elastomers Derived from Menthide and Tulipalin A

Renewable ABA triblock copolymers were prepared by sequential polymerization of the plant-based monomers menthide and α-methylene-γ-butyrolactone (MBL or tulipalin A). Ring-opening transesterification polymerization of menthide using diethylene glycol as an initiator gave α,ω-dihydroxy poly­(menthide) (HO-PM-OH), which was converted to α,ω-dibromo end-functionalized poly­(menthide) (Br-PM-Br) by esterification with excess 2-bromoisobutyryl bromide. The resulting 100 kg mol^–1 Br-PM-Br macroinitiator was used for the atom transfer radical polymerization of MBL. Four poly­(α-methylene-γ-butyrolactone)-<i>b</i>-poly­(menthide)-<i>b</i>-poly­(α-methylene-γ-butyrolactone) (PMBL-PM-PMBL) triblock copolymers were prepared containing 6–20 wt % PMBL, as determined by NMR spectroscopy. Small-angle X-ray scattering, differential scanning calorimetry, and atomic force microscopy experiments supported microphase separation in the four samples. The mechanical behavior of the triblocks was investigated by tensile and elastic recovery experiments. The tensile properties at both ambient and elevated temperature show that these materials are useful candidates for high-performance and renewable thermoplastic elastomer materials

Vegetable Oil-Derived Polyamide Multiblock Copolymers toward Chemically Recyclable Pressure-Sensitive Adhesives

A series of poly[amide11-alt-poly(dimer acid-alt-1,5-diamino-2-methyl)] multiblock copolymers [PA11Hx-alt-(DA-MP)Sy] with high renewable content (up to 95%) was synthesized via bulk polycondensation of a plant oil-based diacid-terminated PA11 hard block (PA11Hx) and a diamine-terminated PA soft block [(DA-MP)Sy] (wsoft block = 0.31–0.90). The tunable and superior mechanical properties (E = 4–233 MPa, σyield = 20–33 MPa, σb = 744–2233%, and γ = 222–359 MJ m–3) of the PA11Hx-alt-(DA-MP)Sy depended on the chain lengths of both the crystalline hard block and the amorphous soft block. The performance of the pressure-sensitive adhesive (PSA) system that includes the multiblock was assessed, revealing a peel strength of 3.52 N cm–1, a probe tack of 0.45 N, and shear strength of >50 000 min, which are competitive to commercial PSA tape. The molecular structure of the PA11Hx-alt-(DA-MP)Sy was analyzed by 1H NMR, 13C NMR, FTIR, TBN, and GPC. High-purity monomers were recovered through acid-catalyzed hydrolysis of a sustainable multiblock copolymer with >99% conversion rate (calculated based on crude 1H-NMR analysis). These novel multiblocks and the chemical recycling method could provide a potential for sustainability

Artificial DNA Lattice Fabrication by Noncomplementarity and Geometrical Incompatibility

Fabrication of DNA nanostructures primarily follows two fundamental rules. First, DNA oligonucleotides mutually combine by Watson–Crick base-pairing rules between complementary base sequences. Second, the geometrical compatibility of the DNA oligonucleotide must match for lattices to form. Here we present a fabrication scheme of DNA nanostructures with noncomplementary and/or geometrically incompatible DNA oligonucleotides, which contradicts conventional DNA structure creation rules. Quantitative analyses of DNA lattice sizes were carried out to verify the unfavorable binding occurrences, which correspond to errors in algorithmic self-assembly. Further studies of these types of bindings may shed more light on the exact mechanisms at work in the self-assembly of DNA nanostructures

Poly(amide11)-Incorporated Block Copolymers as Compatibilizers to Toughen a Poly(lactide)/Polyamide 11 Blend

We added a block copolymer compatibilizer to a thermodynamically immiscible blend of poly(lactide) (PLA) and poly(amide11) (PA11) and achieved a maximum strain at break (εb) and toughness (γ) of 467% and 157 MJ m–3, respectively, which were about 30 times higher than those of the neat PLA/PA11 blend system, while maintaining a yield stress (σyield) of 87% that of the neat PLA homopolymer. The PLA and PA11 based di-, tri-, and multiblock copolymer compatibilizers were synthesized via bulk polycondensation reactions of 11-aminoundecanoic acid (11-AUDA) and hexamethylene diamine (HMDA) or decylamine without the use of solvents. This was followed by a mechanochemical ball milling reaction between the resulting polyamide 11 containing di- or mono terminated amine end-groups and d,l-lactide through ring-opening polymerization (ROP) and urethane linkage reaction. The morphology of the prepared PLA/PA11/compatibilizer blend was investigated by O-PTIR and AFM analyses. As the content of the multiblock compatibilizer increased from 0 to 0.2, 0.5, and 1 wt %, the size of the domain droplets dramatically decreased, from 2.4 to 1.4 μm, and the interfacial thickness increased from 17.0 to 25.5, 55.2, and 76.9 Å, thereby supporting increased adhesion at the PLA/PA11 interface. Mechanical property analyses demonstrated that the mechanical properties improved as the amount of compatibilizer was increased from 0 to 0.2, 0.5, and 1 wt %, as the molecular weight (MW) of the blocks increased beyond the critical molecular weight (Mc) and the MW for cocrystallization, and as the number of blocks increased. The findings of this study demonstrate the potential of enhancing the mechanical properties of biobased polymer blends by incorporating block copolymer compatibilizers. This could help expand the broad range of applications for biobased polymers suitable for various fields

High-Performance Pressure-Sensitive Adhesives from Renewable Triblock Copolymers

High-Performance Pressure-Sensitive Adhesives from Renewable Triblock Copolymer

Effects of Hard Segment Length on the Mechanical Properties of Poly(PA11-<i>co</i>-DA) Periodic Copolymers

Polyamide 11 (PA11) is a semicrystalline polymer with excellent mechanical property. However, the use of PA11 with high crystallinity as an engineering plastic is limited because of its low impact resistance. In this work, a series of sustainable poly­(PA11-co-DA) copolymers (PAx-p-DAy) were synthesized via polycondensation from vegetable oil-based dimer acid (DA) and diamine terminated polyamide 11 (ATPA11-x). The molecular structure of PAx-p-DAy was characterized by 1H NMR, 13C NMR, FT-IR, XRD, and viscometry. The mechanical properties of the periodic copolymers depended on the bulky DA content and the chain length of ATPA11-x. As the content of bulky DA increased and the chain length of ATPA11-x decreased, the degree of crystallinity of the PAx-p-DAy copolymers decreased, but the tensile strength, elongation, and tensile toughness increased. In addition, the low-temperature and room-temperature impact toughness of the copolymer was also remarkably improved. These thermoplastic polyamides have the potential to be widely applied