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Polyurethane (PU) nanofibers were fabricated by solution blowing. The effects of polymer concentration, gas pressure and temperature on morphology and diameter of fiber were discussed. The results show that the fiber with mean diameters in 100nm- 400nm range was successfully obtained, and when the mass fraction of the solution increases, the diameter of the fiber increases. On the whole, the evenness of the fiber diameter tends to decrease. The gas pressure and the temperature affect the fibers’ diameter, and as the gas pressure increase, the diameters of the fiber decrease, while the fiber diameter is gradually larger as the temperature increasing.

Polyester fiber needle-punched nonwovens with different structures were manufactured and their sound absorption properties were examined using the standing wave tube method. The results show that the sound absorption property of the nonwovens depends on their thickness, needling intensity, fiber diameter and surface structure.

To improve the thermal behavior of cellulose diacetate, cellulose diacetate-graft-poly(lactic acid) copolymers (CDA-g-PLAs) were synthesized by ring-opening polymerization of L-lactide using stannous octoate (Sn(Oct)2) as catalyst. The molecular structure of the copolymer was characterized by FT-IR and 1H-NMR and the thermal properties were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG-DTA). The results showed that the product was grafted copolymer of cellulose diacetate-graft-poly(lactic acid) with different side-chain structure. The thermal processing properties of CDA-g-PLAs are remarkably improved with melting temperature(Tm) about 140°C which lower than that of CDA and decomposition temperature (Td) higher than 260°C.

Nonwoven fabrics possess good acoustics properties and are used widely in many fields. Based on the Zwikker and Kosten theory, this paper suggests a numerical method for calculating their acoustical absorption coefficient.