Thermoplastic polyurethane (TPU) supramolecular networks with hybrid hard segments composed of 1,4-benzoquinone dioxime (BQDO) and/or ureidopyrimidinone (UPy) (TPU-Q, TPU-U or TPU-QU) have been successfully achieved through pre-polymerization and subsequent chain extension. The composition of hard segments can be tuned by adjusting the feed ratio of BQDO to UPy, due to the high conversion of chain extenders. Triple reversible networks are constructed through the synergistic effects of various interactions in hard segments including abundant quadruple hydrogen bonds, ordered π-π stacking and oxime-urethane bonds. The BQDO structural units serve as both robust sites for ensuring network integrity and photothermal sites for accelerating network reorganization, and UPy structural units act as cooperated sites to enhance the network strength and hysteresis. The synergistic effects in hard segments increase the network strength and network reversibility simultaneously, leading to a high tensile strength of 24.1 MPa, a high dissociation point of 116.5 °C, a low activation energy for network reorganization of 43.6 kJ mol-1 and a wide damping range at low temperature. Robust self-healing of TPU-QU supramolecular networks has been achieved in the presence of NIR irradiation, leading to a high self-healing efficiency of 99.2% at NIR intensity of 200 mW cm-2 within 10 min. The accelerated self-healing is caused by strong and stable photothermal conversion achieved under 808 nm irradiation, since the aggregated BQDO structural units in HSs exhibit a narrow energy gap and thus a high photothermal temperature of 180 °C at NIR intensity of 500 mW cm-2. These TPU-QU elastomers would have potential applications in soft devices and photosensitive self-healing materials.

The inert carbon-carbon bonds of aromatic systems have long impeded the direct diversification of phenolic feedstocks into value-added scaffolds. Although enzymatic or energy-intensive strategies enable limited arene modifications, the controlled and programmable ring opening of phenols to unlock both skeletal and functional group diversity remains a fundamental challenge. Here we report an operationally simple and efficient nitrogenation strategy for cleaving phenolic arene rings, converting phenols into uniquely structured acyclic N-containing products including cyanopenta-dienoates, cyanopenta-dienamides and cyanopenta-dienoic acids. The method also enables scaffold hopping of corresponding arene rings, leading to important five-, six- and seven-membered N-heterocycles. The strategy demonstrates broad utility in late-stage modification of bioactive molecules, diversified skeletal remodelling of phenolic feedstocks, and the application of ring-opening products in polymer development. This approach transforms phenols into programmable linchpins for accessing underexplored chemical space, offering broad potential for synthetic chemistry and materials science.

The unique hydrophilic and antifouling films of poly(thioctic acid)–Fe 3+ hybrid co-networks (PTA–Fe) were successfully prepared by hydration under humid conditions.

The novel chemically stable hybrid co-networks (PTA-Fe) of poly(thioctic acid) coordinated with molar content (CFe) of 1%∼12% Fe3+ generated from [FeCl4·POH]- can be in situ synthesized via controlled/living cationic ring-opening polymerization of α-thioctic acid (TA) with tert-butyl chloride(BCl)/FeCl3/isopropanol(POH) initiating system at 0 °C. The polymerizations are all in first order with respect to monomer, initiator and co-initiator. The resulting PTAs with desired molecular weights and relatively narrow unimodal molecular weight distribution can be obtained via quantitative initiation by changing [BCl]0. The livingness of polymerization without chain transfer and termination is confirmed from the linear relationship between molecular weights of the resulting PTAs and polymer yields and the unchanged average polymer chains during polymerization process by Incremental Monomer Addition and All Monomer In techniques. The possible mechanism of the above polymerization is proposed. Interestingly, it is found that the PTA-Fe hybrids can behave chemically stable during storage at room temperature for 24 months when CFe ≥ 6.9%. To the best of the knowledge, it is the first example of in situ green synthesis of PTA-Fe hybrid co-networks with excellent chemical stability. The PTA-Fe hybrids would have potential application in the field of elastomer, adhesive and self-healing materials.

The rheological and tensile behaviors of polyisobutylenes (PIBs) with different molecular weights were studied. The structural evolution of ultrahigh molecular weight PIB (UHMW-PIB) during uniaxial and cyclic deformation was traced by wide-angle X-ray diffraction (WAXD). The molecular weight of PIB in relation to its viscosity, viscoelasticity and elasticity was determined. The UHMW-PIB, which is mainly elastic, exhibits excellent ductility during uniaxial tensile process. The results of WAXD indicate that the stretch-induced crystallization takes place in the UHMW-PIB when stretched to large ratio. As the stretching ratio is 11, the crystallinity of UHMW-PIB with weight-average molecular weight of 3.28x106 g/mol is as high as 10.7%. The UHMW-PIB shows good strain recovery performance after cyclic stretching. Compared to the thermoplastic polyurethane in the literature, the residual ratio of UHMW-PIB is much lower when the stretching ratio is the same. In the unloading process, the formed crystallites will gradually melt and return to the amorphous state. The tensile behavior of PIB is closely related to its molecular weight, entanglement structure and stretch-induced crystallization. This work would provide reference for the industrial application of PIB.

The sulfonated poly(α-methyl styrene-b-isobutylene-b-α-methyl styrene) copolymers (S-ASIBS) with the average molar percentage of sulfonic acid (-SO3H) groups (SP) ranging from 3.6 mol

Poly(styrene-b-isobutylene-b-styrene) triblock copolymer (SIBS) is an entirely saturated thermoplastic elastomer with an inherent microphase separation due to the thermodynamic incompatibility of hard polystyrene (PS) and soft polyisobutylene (PIB) segments. The mechanical properties are normally improved by increasing the composition of PS and molecular weight of SIBS. The high performance SIBS-based composites with a small amount (<= 0.7 %) graphene oxide-graft-polystyrene (GO-g-wPS) hybrids have been prepared by construction the unique bicontinuous micromorphology and physically cross-linked 3D network. The GO-g-wPS hybrids carrying w-shaped PS chains chemically bonded on GO surfaces could be synthesized by the reaction at water/oil interface and the grafting density (GD) was effectively mediated in the range of 0.06-0.11 mmol g-1 by varying molecular weight (Mn,PS) of PS precursor, reaction temperature and time. The Mn,PS and GD do affect the microphase separation and homogeneous dispersion of GO sheets in the SIBS/GO-g-wPS composites. It is found that the formation of the unique bicontinuous microphase separation morphology can be mainly induced by GO-g-wPS in the composites by keeping SIBS at the same, leading to the great enhancement in mechanical properties even at a very low content of GO-g-wPS. The optimized composite of SIBS with 0.5 % of GO-g0.11-wPS7.6k behaves much higher modulus of 446 MPa, tensile strength of 24 MPa and toughness of 57 MJ m-3 than those (15.7 MPa, 14.0 MPa and 21.9 MJ m-3) of SIBS, respectively. This mechanical tunability offers a useful strategy for developing high-performance nanocomposites with potential applications in biomedical, robotics and energy fields.

The controlled cationic copolymerizations of isobutylene (IB) with alkenyl styrenes including 4-allylstyrene, p-(3-butenyl)-styrene and p-(5-hexenyl)-styrene were carried out in n-hexane/CH2Cl2 (6/4 v/v) at −80 °C using a t-BuCl/FeCl3/iPrOH initiating system.

The synthesis of ultra-high-molecular-weight (UHMW) ethylene-propylene (EP) polar elastomers with high functional degree represents a great challenge. The modification of UHMW EP-5-ethylidene-2-norbornene (ENB) terpolymers (EPDM) with a high content of ENB structural units provides a viable way. The synthesis of UHMW EPDM with a high content of ENB structural units is critical for the preparation of UHMW polar EP elastomers with high functional degree. Herein, the copolymerization of ethylene with propylene and the terpolymerization of ethylene and propylene with ENB were investigated by using N-heterocyclic carbene vanadium complex NHCVOCl3 (PhCH2NCH=CHN(2,4,6-Me3C6H2R)C:VOCl3). The UHMW EPDM (Mw = 1059-1586 kgmol-1) were successfully prepared with high catalytic activity of <= 2.65 x 105 g polymermol-1 of Vh-1. The content of ENB structural units in resulting EPDMs can be increased to 12.5 mol% (35.4 wt%) by increasing the ENB concentration in monomer feed. The epoxidation of UHMW EPDM with m-chloroperbenzoic acid in tetrahydrofuran results in an efficient conversion of C=C double bonds in the ENB structural units into epoxy groups. The functionalized EP elastomers containing epoxy groups of <= 11.2 mol% have been successfully synthesized. The epoxy groups in the functionalized EP elastomers can be successfully and quantitatively converted into carbonyl groups, affording functionalized EP elastomers with a high content of norcamphor structural units of <= 11.2 mol%. The UHMW EPDM with a high content of polar epoxy or carbonyl groups can behave with good compatibility with inorganic fillers, which is a benefit for the preparation of high-performance composites of UHMW EPDM with inorganic fillers. Ultra-high molecular weight ethylene-propylene-diene rubber is produced via the copolymerization of ethylene with propylene and the terpolymerization of ethylene and propylene with 5-ethylidene-2-norbornene using a vanadium catalyst.

The hybrid co‐networks (PTA‐Fe) of poly(thioctic acid) (PTA) coordinated with Fe 3+ having PTA polymers with the number‐average molecular weight ( M n ) of 1–60 kg mol −1 and molar Fe 3+ content ( C Fe ) of 0%–31% have been successfully in situ synthesized. The PTA‐Fe film shows high transmittance of 97% with 6.9% ≤ C Fe ≤ 16.1% and M n ≥ 12.5 kg mol −1 . The PTA‐Fe film reveals self‐focusing phenomenon especially under 808 nm irradiation, due to the nonlinear refraction caused by the polarized charge transfer complex (CTC) in hybrids excited photons. Meanwhile, the refractive index at 589 nm ( n D ) of PTA‐Fe hybrid increases from 1.54 to 1.68 with incremental C Fe for the disulfides and CTC structures. The Abbe number ( ν D ) of PTA‐Fe hybrids slightly decreases (47–45) due to their self‐focusing behavior. The PTA‐Fe materials show adjustable photothermal conversion under 808 nm irradiation by mediating C Fe or NIR intensity ( I 808 ). The photothermal conversion efficiency (PCE) of PTA‐Fe hybrid can reach 98% even at low I 808 of 50 mW cm −2 , for the PTA‐Fe hybrid with self‐focusing character can converge the light into a point inside the materials. The multifunctional PTA‐Fe hybrid co‐networks with high performance in optical transparency, focusing, and photothermal conversion would have potential applications in advanced optical materials.

A six-coordination stable structure of Ni2+ with two carboxylate ligands and two sulfur atoms in side chains of ethylene-propylene copolymers can be constructed to form 3D physically cross-linked networks according to a density functional theory simulation. The reversibly cross-linked polar ethylene/propylene/5-ethylidene-2-norbornene copolymer elastomers (rcEPDMs) with triple noncovalent cross-linking sites of hydrogen bonds, ionic aggregation, and 6-coordination Ni2+ bonds can be successfully in situ prepared by the reaction of carboxyl functionalized EPDM with NiCl26H2O in the presence of tetrabutylammonium hydroxide. The rcEPDM networks with Ni2+ having a coordination number of 6 (rcEPDM-Ni2+) show much higher cross-linking density than their analogues with Zn2+ having a coordination number of 4 (rcEPDM-Zn2+), which is confirmed by swelling experiments and Mooney-Rivlin analysis. The rcEPDM-Ni2+ networks exhibit a much higher tensile strength of 19.0 MPa at an elongation of 587% than rcEPDM-Zn2+ networks (6.8 MPa at 777%). The mechanical properties of rcEPDM-Ni2+ networks containing triple cross-linking sites are superior to those of networks containing hydrogen and coordination bonds as well as those containing ionic aggregation and coordination bonds. The hysteresis energy of rcEPDM-Ni2+ networks increases by 19 times, and the strain recovery reaches 95% when the strain gradually increases from 50% to 400%, which is attributed to the synergy of noncovalent cross-linking sites. The hysteresis energy of rcEPDM-Ni2+ network is 66% higher than that of rcEPDM-Zn2+ networks at 400% strain, due to the formation of a more stable and dense six-coordination structure of rcEPDM-Ni2+ networks. To the best of our knowledge, this is the first example of renewable triple noncovalently cross-linked polar EPDM with high strength and outstanding strain recovery using Ni2+-carboxylate coordination bonds. The renewable cross-linked EPDM elastomers would have potential applications in organic-inorganic composite materials, bonding agents, sealing parts, and reusable elastomers.

Sulfonated polystyrene-b-polyisobutylene-b-polystyrene copolymers (SSIBS) with various average molar percentages of sulfonic acid side groups based on all the structural units along SSIBS polymer chains (SP) were synthesized via sulfonation of SIBS with acetyl sulfate. A transmission electron microscopy (TEM) method was developed to directly observe the dark phase of -(SO3)(2)Pb ionic channels of sulfonic acid ion clusters by the ion exchange of H+ with Pb2+. The size of hydrophilic ionic channels in SSIBS enlarged with increasing SP and the desired interconnected ionic transport channels could be formed in SSIBS with SP of more than 6.9 mol %. Effects of copolymer composition and functionality on micromorphology and finally on electrochemical properties of the SSIBS membranes show that the SSIBS membranes with bicontinuous phase separation micromorphology exhibit high through-plane proton conductivity, low fuel permeability, and high selectivity. The optimized SSIBS-3160-13.4 membrane was selected for assembling the single direct methanol fuel cell (DMFC) and the DMFC exhibits high performances of open circuit voltage (OCV) of 560 mV, limiting current density (J(lim)) of 650 mAcm(-2), and peak power density (P-max) of 32.24 mWcm(-2). These fuel cell performances are similar to those (OCV = 510 mV, J(lim) = 600 mAcm(-2), and P-max = 35.56 mWcm(-2)) by using the commercial Nafion 117 membrane under the same conditions. To the best of our knowledge, this is the first example of SSIBS-based DMFC exhibiting comparable performances with Nafion 117 under the same test conditions.

A series of amphiphilic polyisobutylene-b-poly (2-ethyl-2-oxazoline) (PIB-b-PEOX) diblock copolymer/Ag nanoparticle composites were successfully in-situ synthesized via cationic ring-opening polymerization of 2-ethyl-2-oxazoline (EOX) with high initiation efficiency by using allyl bromide end functionalized polyisobutylene (PIB-allylBr) as a macroinitiator and AgClO4 as a coinitiator. The microphase separation formed in the resulting PIB-b-PEOX diblock copolymers due to the thermodynamic imcompability of hydrophilic PEOX segments and hydrophobic PIB segments. The micromorphology of phase separation is dependent on the copolymer composition, in which sea-island micromorphology formed for PIB118-b-PEOX80 and bicontinuous phase micromorphology formed for PIB118-b-PEOX97. The micelles with nano-scale size in the range of 15-80 nm and having high drug loading rate of ca. 48.9 % can be formed by self-assembly of the amphiphilic diblock copolymers in n-hexane. The drug cumulative release rate can be increased with an increase in the proportion of PEOX segments, due to the strong interaction between ibuprofen and the PEOX segments. The hydrophilicity of the PIB-b-PEOX diblock copolymer surfaces can be improved after ethanol vapor induction. The PIB-b-PEOX diblock copolymers behave biocompatibility and good anti-protein adsorption property. The amphiphilic PIB-b-PEOX diblock copolymer/Ag nanoparticle composites exhibit high antibacterial efficiency for Gram-negative bacterium (E. coli) and Gram-positive bacterium (S. aureus). To the best of our knowledge, this is the first example of PIB-b-PEOX diblock copolymer/Ag nanoparticle (6.4 +/- 2.6 nm) composites synthesized in-situ with good biocompatibility, anti-protein adsorption, and antibacterial properties, which would have potential applications for drug delivery and anti-protein coating in biomedical areas.

The novel polybutadiene rubbers (CVBR) carrying 88-97% of long cis-1,4 polybutadiene segments (cis-PB, cis-1,4 content >98.3%) and 3-12% of long syndiotactic1,2-polybutadiene segments (sPB, 1,2 content >87.0%) could be successfully synthesized via in-situ coordination polymerizations of butadiene in hexanes in our lab and also be scaled up via continuous polymerization process in pilot (scale: 200 t/a). The natural rubber (NR)-based compound formulations containing different contents of CVBR, and carbon black (CB) fillers were developed and the optimized NR/CVBR/CB vulcanizates with 40% of CVBR were manufactured for the sidewall of all-steel giant offthe-road tire. The storage modulus of NR/CVBR/CB compounds and the elastic modulus, tensile strength and tear strength of NR/CVBR/CB vulcanizates could be remarkably increased by increasing CVBR content. The crack generation and growth could be effectively restricted due to both the fast relaxation, the rigid polymer-filler interface and synergistic effect of high cis-polybutadiene and crystalline 1,2-polybutadiene particles on the strain-induced crystallization behaviors of rubber matrix. The heat build-up of NR/CVBR/CB vulcanizates could be greatly reduced by introduction of cis-PB segments in CVBR for the easy mobility and low hysteresis of macromolecular chains. The NR/CVBR/CB vulcanizates with high strength and elastic modulus, good flex fatigue crack resistance and low heat build-up would meet the requirement for high performance sidewall in manufacturing giant all-steel off-the-road tires.

Ethylene/propylene/5-ethylidene-2-norbornene terpolymers with high ENB incorporation and ultra-high molecular weight were synthesized by using imidazolidin-2-iminato vanadium complexes.

Neodymium-based polybutadiene rubber (Nd-BR) with cis-1,4 content >98.0% was prepared by neodymium carboxylate-based catalyst system and Nd-BR with cis-1,4 content of 94.9% was prepared by neodymium phosphonate-based catalyst system. Commercial products with similar molecular weight (M-n) and molecular weight distribution (M-w/M-n) while different cis-1,4 contents were selected for comparison. The effects of cis-1,4 configuration on properties of Nd-BRs with similar 1,2-configuration content, molecular weight and distribution were investigated. The characteristic stress relaxation time (tau) decreased obviously when the total content of 1,4-configuration (cis-1,4 and trans -1,4) is greater than 99%, and the cis-1,4 content increases from 94.9% to 98.8%, indicating the improvement of processability. The dispersion of carbon black in rubber and bound rubber content of Nd-BR composites were improved as well. The strain-induced crystallization capability was enhanced with the increase of a small amount of cis-1, 4 content, which significantly improved the tensile strength, tear strength, wear resistance, puncture resistance and crack resistance. It is remarked that the rolling resistance and wet-skid resistance were increased with ultra-high cis-1,4 content of more than 98%. Nd-BR with ultrahigh cis-1,4 content of ca. 98.5% and appropriate molecular weight distribution (ca. 2.8) possessed excellent processing properties, mechanical properties and dynamic mechanical properties, which is suitable for the high-performance tires. [GRAPHICS] .

The highly efficient method has been developed for the synthesis of NHC-VOCl3 containing symmetrical or unsymmetrical N-heterocyclic carbene (NHC) ligands by the transmetallation reaction of NHG·AgCl with VOCl3. The total isolated yield of VOCl3[1,3-(2,4,6-Me3C6H2)2(NCH=)2C:] (V4′) reached 86

Liquid trimethoxy silane-functionalized cis-polybutadiene (cis-PB-Si(OMe)3), possessing number-average molecular weights of cis-PB segments (Mn,PB) ranging from 1800 g/mol to 5400 g/mol, with cis-1,4 content of ca. 80

The graft copolymer of poly-(N-epsilon-carbobenzyloxy-L- lysine)-g-poly(tetrahydrofuran) (PZLL-g-PTHF) could be successfully synthesized via the nucleophilic substitution reaction of PTHF+ living polymer chains with secondary amine side groups in the PZLL backbone. The amphiphilic graft copolymers of polylysine-g-poly(tetrahydrofuran) (PLL-g-PTHF) could be obtained by complete deprotection of the precursor of PZLL-g-PTHF. The obvious microphase separation was observed in both PLL-g-PTHF and PZLL-g-PTHF because of the incompatibility between the two kinds of segments. Their micro morphology is dependent on the chemical structure of backbones and the grafting number (GN) of branches. PZLL-g-PTHF is a hydrophobic graft copolymer and the water contact angles (WCAs) of copolymer surfaces decreased from 103 to 91 & DEG; with the increase of GN from 5 to 21. Interestingly, PLL-g-PTHF is an amphiphilic graft copolymer and their WCAs increased from 52 to 90 & DEG; with the increase of GN from 5 to 21. Both PZLL-g-PTHF and PLL-g-PTHF copolymers show good biocompatibility and anti-protein adsorption. The resulting PZLL-g-PTHF copolymers carrying a small amount of Ag nanoparticles, in situ generated from coinitiator AgClO4 for the synthesis of PTHF+ living chains, exhibit high killing efficiency (> 95%) for both Escherichia coli and Staphylococcus aureus. PLL-g-PTHF/Ag nanocomposites show extremely high killing efficiency (> 99%) against both S. aureus and E. coli for binary contribution from Ag nanoparticles and PLL. The antifouling and antibacterial graft copolymers would potentially have biological and medical applications.

The acylated propylene glycol alginate-g-polytetrahydrofuran amphiphilic graft copolymers (APGA-g-PTHF) with various grafting numbers (G(N)) of 3-23 per 1000 monosaccharide rings and PTHF (PTMG or PTMO) branches with different molecular weights (M-n,M-PTHF) of 600-3400 g/mol could be successfully synthesized via nucleophilic substitution of PTHF living chains carrying oxonium ions with the -OH side groups of APGA backbone. The nanophase separation, the hydrophobicity and the surface roughness were increased due to the less restricted movement of hydrophobic PTHF branches to the surface. APGA-g-PTHF graft copolymers behave low cytotoxicity and good anti-protein performance. Interestingly, APGA-g-PTHF amphiphilic graft copolymers could form homogeneous nanospheres (< 250 nm) via self-assembly in H2O/CH2Cl2 medium which could be used for drug (ibuprofen or curcumin) carriers having high drug loading efficiency (similar to 45%) and fast release behavior. The nanospheres carried curcumin behave very higher (10-fold) anticancer effect against HeLa cells than that of curcumin and thus reduce the harmful drug dosage. Moreover, the nanospheres carried drug might enter into HeLa cells and present pH-sensitive drug release. To the best of our knowledge, this is the first example of PGA based graft copolymers for highly effective nano-carriers and anti-protein surfaces, which would have a prospect in biomedical areas.