With triisobutylaluminum as a protection reagent, copolymerizations of ethylene with 10-undecen-1-ol, 10-undecenoic acid, and 5-hexen-1-ol have been performed with bis[(3,5-di-t BuÀ ÀC 6 H 2 À À2-O)À ÀPhC¼ ¼N(2-FÀ ÀC 6 H 4 )]ZrCl 2 (a)/methylaluminoxane or bis[(3,5-di-t BuÀ ÀC 6 H 2 À À2-O)À ÀPhC¼ ¼N(2-FÀ ÀC 6 H 4 )]TiCl 2 (b)/methylaluminoxane as the catalyst. Both catalysts exhibit high activities of copolymerization in the presence of polar groups. The properties of the copolymers are strongly affected by the central metal properties of the catalysts. In comparison with complex a, titanium complex b appears to be less sensitive to polar monomers and more favorable for the preparation of higher molecular weight functionalized polyethylenes containing higher contents of polar groups. Studies on the polymerization temperature indicate that the catalytic activities decrease greatly with both complex a and complex b. The comonomer contents incorporated into the copolymers are slightly dependent on the polymerization temperature in the case of complex a, whereas in the case of complex b, the effect of the polymerization temperature is more distinct: an increase in the polymerization temperature can efficiently facilitate the incorporation of polar comonomers. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: [59][60][61][62][63][64][65][66][67][68] 2007

It is of increasing interest to develop high-performance antioxidants for polypropylene (PP). Here, we have developed an organic−inorganic hybrid antioxidant by direct intercalation of low-molecular-weight hindered phenolic antioxidant (AO) into the interlayer region of layered double hydroxides (LDH), prepared the AO-LDH/PP composites following a simple solvent washing method, and investigated the thermal stability of the AO-LDH/PP composites by an accelerated aging method at 150 °C under air atmosphere. The results show that the one-step synthesis method is available to produce the AO-LDH with a basal spacing of 2.8 nm and that the addition of AO-LDH does not influence the crystallization behavior of PP. Furthermore, the radical-scavenging ability of AO-LDH is similar to that of the AO species. The AO-LDH significantly improves the long-term thermal stability of PP related to the CO 3 -LDH. The AO-LDH exhibits excellent antioxidative performance with promising applications in the field of polymers.

The development of polymer electrolytes with good ion transport capacity and high mechanical strength is a big challenge for solid polymer electrolytes.

Activated with methylaluminoxane (MAO), phenoxy‐based zirconium complexes bis[(3‐tBu‐C6H3‐2‐O)‐CHNC6H5]ZrCl2, bis[(3,5‐di‐tBu‐C6H2‐2‐O)‐PhCNC6H5] ZrCl2, and bis[(3,5‐di‐tBu‐C6H2‐2‐O)‐PhCN(2‐F‐C6H4)]ZrCl2 for the first time have been used for the copolymerization of ethylene with 10‐undecen‐1‐ol. In comparison with the conventional metallocene, the phenoxy‐based zirconium complexes exhibit much higher catalytic activities [>107 g of polymer (mol of catalyst)−1 h−1]. The incorporation of 10‐undecen‐1‐ol into the copolymers and the properties of the copolymers are strongly affected by the catalyst structure. Among the three catalysts, complex c is the most favorable for preparing higher molecular weight functionalized polyethylene containing a higher content of hydroxyl groups. Studies on the polymerization conditions indicate that the incorporated commoner content in the copolymers mainly depends on the comonomer concentration in the feed. The catalytic activity is slightly affected by the Al(MAO)/Zr molar ratio but decreases greatly with an increase in the polymerization temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5944–5952, 2005

The semicrystalline polyethylene (PE) and amorphous poly(ethylene-co-norbornene) copolymer have been used in a wide variety of applications, especially in packaging. It is a big challenge to improve the transparency of...

The prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM) is increasing and there is an urgent need for new treatment strategy to prevent progression of hepatic steatosis and fibrosis. We have performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in the treatment of hepatic steatosis and fibrosis in patients with T2DM and NAFLD. The PubMed, Web of Science, Scopus, Embase and Cochrane Central Register of Controlled Trials databases were searched for articles that met the eligibility criteria to explore the efficacy and safety of GLP-1RAs in patients with T2DM and NAFLD. We assessed pooled data using a random/fixed-effects model according to the I2 and p-values. Eight trials that included a total of 468 participants were eligible for inclusion in the review. For primary outcomes, administration of GLP-1RAs significantly decreased the content of intrahepatic adipose (IHA)[p=0.007, weight mean difference (WMD) -3.01, 95% confidence interval (CI) -4.75, -1.28], subcutaneous adipose tissue (SAT) (p<0.00001,WMD -28.53,95%CI -68.09,-26.31), and visceral adipose tissue (VAT) (p<0.0001,WMD -29.05,95%CI -42.90,-15.9). For secondary outcomes, GLP-1RAs produced a significant decrease in levels of alanine aminotransferase(ALT)(p=0.02, WMD -3.82, 95%CI -7.04, -0.60), aspartate aminotransferase (AST) (p=0.03, WMD -2.4, 95%CI -4.55,-0.25, I2 = 49%), body weight (p<0.00001,WMD -3.48,95%CI -4.58,-2.37), body mass index (p<0.00001,WMD -1.07,95%CI -1.35,-0.78), circumference waist (p=0.0002,WMD -3.87, 95%CI -5.88, -1.86) fasting blood glucose (p=0.02, WMD -0.35, 95%CI -0.06, -0.05), HbA1c (p<0.00001,WMD -0.39,95%CI -0.56,-0.22), HoMA-IR(p=0.005, WMD-1.51, 95%CI-0.87,-0.16), total cholesterol (p=0.0008, WMD -0.31, 95%CI -0.48, 0.13) and triglycerides (p=0.0008, WMD -0.27, 95%CI -0.43,-0.11) in comparison with the control regimens. The main adverse events associated with GLP-1RAs included mild-to-moderate gastrointestinal discomfort and nonsense hypoglycemia that resolved within a few weeks. GLP-1RAs were an effective treatment that improved intrahepatic visceral and subcutaneous adipose tissue, inflammatory markers, the anthropometric profiles and some metabolic indices in patients with T2DM and NAFLD, GLP-1RAs could be considered for use in these if there are no contraindications. Further studies are needed to understand the direct and indirect effects of GLP-1RAs on NAFLD and the potential mechanism via which they prevent its progression.Systematic Review Registration: PROSPERO, identifier CRD42021265806.

The synthesis of isotactic polypropylene (iPP)-based block copolymers by means of controlled isoselective polymerization of propylene with high turnover frequencies is an ongoing challenge in industry and academia. Herein, we report a new strategy for reversible coordinative chain transfer polymerization of propylene and propylene−ethylene with a pyridylamido hafnium/[Ph 3 C][B(C 6 F 5 ) 4 ] catalyst system and iBu 3 Al as a chain transfer agent under conditions that were optimized so that the rate constants for chain transfer and chain propagation were similar (k p ≈ k ct ). Using this new strategy, we could obtain iPP-b-poly(ethylene-co-propylene) and iPP-b-poly(ethylene-co-propylene)-b-iPP block copolymers with controlled molecular weights, hard/soft block ratios, and compositions via a continuous-monomer-feeding approach like that used in living polymerization systems. The polymerization reactions produced uniform block copolymers with previously inaccessible microstructures. The copolymers have both a semicrystalline iPP block ([mmmm] > 99%, melting temperature > 155 °C) and soft ethylene−propylene copolymer blocks (glass transition temperature < −30 °C), with tunable high molecular weights (∼210 kDa) and Schulz−Flory distributions (PDI < 2.5). These promising block copolymers possess dramatically improved tensile properties (30−50-fold increase in elongation at break) relative to those of the iPP homopolymer, whereas the yield strength and strength at break were similar to those of the iPP homopolymer. By tuning the block composition and hard/soft block ratio, we could obtain block copolymers ranging from ductile elastomers to tough plastics. Our new strategy not only sheds significant light on olefin CCTP but also has great potential utility for the industrial production of high-performance polyolefin materials.

The submersible graphene–melamine-sponges present fast and highly efficient adsorption for water soluble dyes.