An investigation of the influence of the contents of original and modified attapulgite (ATP) on the ultradrawing properties of ultrahigh-molecular-weight polyethylene (UHMWPE)/ATP (FA x ) and UHMWPE/modified ATP (FA mx ) as-prepared fibers is reported. Similar to what is found for the orientation factor values, the achievable draw ratios (D ra ) of the FA x and FA mx as-prepared fibers approach a maximum value as the original ATP and/or modified ATP contents reach their corresponding optimum values. The maximum D ra value obtained for FA mx as-prepared fiber specimens is significantly higher than that for FA x as-prepared fiber specimens prepared at the optimum original ATP content. Similar to what is found for the orientation factors and achievable drawing properties, the tensile strength (σ f ) and initial modulus (E) of both drawn F 2 A x and F 2 A mx fiber series specimens with a fixed draw ratio reach maximum values as the original and/or modified ATP contents approach the optimum values, respectively. The σ f and E values of the F 2 A mx fiber specimens are always significantly higher than those of the corresponding F 2 A x fiber specimens prepared at the same draw ratios and ATP contents but without being modified. To understand the interesting ultradrawing, orientation and tensile properties of FA x and FA mx fiber specimens, Fourier transform infrared spectral, specific surface area, transmission electron microscopic and elemental analyses of the original and modified ATPs were performed.

Blends of acrylic polymer (containing acrylonitrile 91.7%, methyl acrylate 7%, and sodium methyl propenyl sulfonate 1.3% [wt %], denoted as PAC) with silk fibroin (SF) were studied in the form of drawn fibers with varied compositions. The strength, elongation, and specific work of rupture of the blend fibers decrease with increase of the SF content, whereas the modulus has a slight increase up to 20% (wt) SF and then decreases. With the addition of up to 30% (wt %) SF in the PAC matrix, the moisture absorption increases from 2.06 to 6.2% in comparison with the PAC. Scanning electron microscopy studies show that the blend fibers have a sheath-core structure, with SF mainly in the sheath and PAC in the core. FTIR, ATR, and X-ray diffraction results of the blend fibers are also presented.

A facile iodine-mediated decarboxylative cyclization from α-amino acids and N-heterocyclic carbaldehydes was developed. By virtue of this method, a series of imidazo[1,5-a]N-heterocycles can be synthesized efficiently under mild conditions. A tentative reaction mechanism was proposed based on the experimental results and previous reports.

A facile CuI-catalyzed and air promoted oxidative cyclization was developed for the synthesis of polyarylated oxazoles. By virtue of this method, a variety of arylated oxazoles could be easily synthesized from readily available starting materials at room temperature in air.