Wen Yong Liu

Effects of Oxalic Acid and Sodium Chloride on the Superhydrophobic Surface on Aluminum Alloy by Anodizing and PP-Coating

We investigated the preparation of the superhydrophobic surface on aluminum alloy by anodizing and PP coating. The effects of oxalic acid and sodium chloride in the electrolytic cell on the superhydrophobic surface were discussed. The results showed that a good superhydrophobic surface was achieved by direct PP coating after anodizing. The addition of oxalic acid had a little enhanced effect on the superhydrophobic surface, while the addition of sodium chloride had an obvious effect on the superhydrophobic surface. When the concentration of NaCl was 1.25 g/L, the contact angle (CA) was up to 162 ° and the sliding angle was lower than 3 ° .

Processing and Mechanical Properties of Starch and PVA Composite Reinforced by MCC

The thermoplastic processing and mechanical properties of starch and polyvinyl alcohol (PVA) composites reinforced with microcrystal cellulose (MCC) were investigated. Glycerol with 30 wt% was chosen as the plasticizer for starch and PVA, respectively. MCC with 2 wt% was used to reinforce the starch/PVA composite. The results showed that the mechanical properties of the obtained starch/PVA blend were best when the glycerol content was 30% of starch and 20% of PVA, and the weight ratio of PVA and starch was 4/6 (wPVA/wstarch). After the addition of MCC, the mechanical properties of the starch/PVA blends were improved, and the tensile strength was increased by 52%. Moreover, it was confirmed by rheological measurements that MCC could interact with the composite materials, which results in the improvement of the mechanical strength of the starch/PVA composites.

Processing and Mechanical Properties of Starch and PCL Composite Reinforced by Nano-SiO2

The thermoplastic processing and mechanical properties of starch and polycaprolactone (PCL) composites reinforced by nano-silica (nano-SiO2) were studied. The results showed that the mechanical properties of the starch/PCL blends improved significantly with the increase of PCL. After the addition of nano-SiO2, the mechanical properties of the starch/PCL blends further improved. When the weight percent of nano-SiO2 was 1.8%, the mechanical properties of the SiO2/TPS/PCL composite were most excellent. By comparison with the starch/PCL (50/50) blends, the tensile strength of the SiO2/TPS/PCL composite with 1.8% SiO2 was increased by 20% and the elongation increased by 33%. Moreover, it was confirmed by rheological measurements that nano-SiO2 could interact with the composite materials, which results in the improvement of the mechanical strength of the TPS/PCL composites.

Effect of POSS on the Compatibility and Mechanical Properties of PC/PLA Blends

Polycarbonate/poly (lactic acid)/(PC/PLA) blends were modified by two kinds of POSS, glycidyl POSS (G-POSS) and Octa-ammonium POSS (O-POSS), respectively. The morphologies and mechanical properties of blends were investigated systematically. The results showed that the adding of O-POSS has a better effect on the compatibility of blend than adding G-POSS, the separate phase is invisible in the morphology of blends, and the mechanical properties of blends are improved significantly with the increase of added O-POSS.

Effect of AMPS and Clay on the Acrylic Acid Based Superabsorbent Hydrogels

A kind of superabsorbent hydrogels was synthesized by an optimized rapid solution polymerization of concertrated partically neutralized acrylic acid in the presence of an organic crosslinker agent under normal atmospheric conditions, 2-acrylamide-2-methyl propane sulfonic acid (AMPS) was added into the gels as co-polymerization monomer to enhance the ability of water absorption. Meanwhile, the hydrophilic nanosized clay Laponite XLG was also added into the gels for improving the shape stability and mechanical properties of gels. Through controlling the ratio of monomers and the content of nanosized clay, the superabsorbent hydrogels with excellent swelling ability and good mechanical properties could be gotten.

The Effect of Various Catalyzers on Transesterification in Reactive Blending PC/PLA Blends

Polycarbonate/Poly (lactic acid) blends were prepared through melt blending at the present of different kinds of organotin catalyzers such as monobutyltin oxide (MBTO), di-n-butyltinoxide (DBTO), di-n-octyltin oxide (DOTO), and dibutyltin dilaurate (DBTL). The effect of kind and mass of catalyzers on the properties of blends were investigated. The results showed that the DBTO is the most effective catalyzer on catalyzing the transesterification between PLA and PC, which corresponds to the analysis of morphologies and mechanical properties of blends. The use of DBTO could improve the compatibility and thus strengthen the mechanical properties of blends signficantly , and the optimal mass is 0.8wt% of blends.

Study on the Mechenical Properties of PPC/PLA Blends Modified by POSS

Aliphatic polycarbonate Polycarbonate/poly (lactic acid)/(PPC/PLA) blends were prepared by melt blending, 1,2-propanediol isobutyl POSS (P-POSS) were added into the blends as a compatilizer and reinforcer. The morphologies, mechanical properties and rheological properties of blends were investigated systematically. The results showed that the adding of P-POSS could improve the compatibilization of PPC and PLA obviously. The thermal stability of the blends was enhanced but the crystallization was effected slightly. Moreover, the tensile strength and impact strength of blends exhibited a considerably increase.

Preparation and Properties Research of PA6/PLA Blends Toughening Modified by TPU

Polyamide 6/Poly(lactic acid) (PA6/PLA) blends introduce the degradability of PLA to high performance PA6, but the bad toughness of both PA6 and PLA limits the application of blends. Aiming at this deficiency, thermoplastic polyurethane (TPU) was used as an additive for modifying the toughness of PA6/PLA blends. PA6/PLA/TPU blends at various compositions were prepared by melt blending, the effects of blend compositions on the morphology, thermal and mechanical properties of blends were investigated. The results showed that the addition of TPU improves the compatibilization between PA6 and PLA and makes the blends show more obvious plastic fracture behavior than PA6/PLA.When the content of PLA in PA6/PLA increases, the impact and tensile strength of blends decrease slightly with the intense decrease of the elongation at break, adding TPU into PA6/PLA blends strengthens the toughness of blends, but the tensile strength of blends decreases. Moreover, the crystallinity of PA6 /PLA blend is hampered by TPU.

Effects of Substrate, Solvent, Graft Density and Graft Length on the Formation of Cellulose-Based Ordered Porous Film

We investigated the preparation of porous film of cellulose-based graft copolymer by breath figure method. The effects of substrate, solvent, graft density and graft length on the formation of porous film were elucidated. The results showed that ordered porous films could be facilely formed on the glass and mica substrate, while no ordered porous films were obtained on the silicon substrate. The ordered porous films were formed from the copolymer/CS2 solution, while no ordered porous films were done from the copolymer/CH2Cl2, CHCl3 and toluene solution. Moreover, no ordered porous films were obtained from the copolymer with spare graft density or with long side chain. The results indicated that the substrate, solvent, graft density and graft length had important effects on the ordered porous film.

Bacteriostasis of a Super-Hydrophobic Micro-Porous Aluminum Surface by a Facile Preparation Method

We investigated the bacteriostasis of the super-hydrophobic surface on aluminum alloy by PP coating. The morphology of the surface was observed by a scanning electron microscopy. The contact angle (CA) was measured by an optical contact angle meter .Staphylococcus aureus and pathogenic escherichia coli adhesion on superhydrophobic surfaces were also evaluated. The inhibition ring test results show the inhibition of Escherichia coli and Staphylococcus aureus were 79.3% and 81.1%, respectively after 24 hours’ contact at 37oC, while the Quinn test demonstrates the surface possesses high resistance to bacterial contamination. The superhydrophobic surface is a factor to reduce device-associated infection and can be used in metal practice.