The effects of hypochlorite level, i.e. 0.5; 1 and 2 active chlorine g/100g starch, on the properties of oxidized maize starch were investigated by FT-IR and solubility of oxidized starch and starch film. The obtained results shown that there was no difference of IR spectroscopy graph between native starch and oxidized starch. Although the analytical results indicated that there were carbonyl and carboxyl production, characteristic vibrations of these groups exhibiting on IR spectra was not clear due to either not enough content of carbonyl and carboxyl groups or covering of strong other absorptions. Notwithstanding, IR spectra also shown the change of intensity of characteristic vibrations. Moreover, solubility of starch oxidized by the highest oxidant content level experienced highest degree while solubility of this starch shown the lowest level. It means that carboxyl in this molecule starch, to some extent, esterified with hydroxyl of either other starch molecules or glycerol to produce crosslink. The obtained results also illustrated that there was a little scission chain in oxidation process when modifying maize starch by sodium hypochlorite.

Acrylic emulsion resin is one of popular matrixes for both outside and inside coatings. It has low cost, high UV and weather resistance, good aesthetics and environmentally friendly. The introduction of inorganic additives in nanosize such as SiO2, TiO2, etc. into acrylic emulsion resin could improve the mechanical and thermal properties of the polymer matrix. The surface modification of nanoparticles can enhance the dispersibility of the nanoparticles in the polymer matrix. This paper presents the characteristics of nanosilica modified with different contents of tri(methoxysilyl)propyl methacrylate silane (MPTS) as a coupling agent and the effect of modified nanosilica on the abrasion resistance and thermal properties of acrylic emulsion resin. The infrared (IR) spectroscopy and thermo-gravimetric analysis (TGA) were used to evaluate the presence of MPTS on the surface of modified nanosilica. Grafting yield of MPTS on the surface of nanosilica was calculated from TGA diagrams. The obtained results showed that nanosilica was surface modified successfully by MPTS with a grafting yield of 47 % when using 3 wt.% of MPTS. After modification, the modified nanosilica became more hydrophobic and can disperse well in acrylic emulsion resin. The modified nanosilica improved significantly the abrasion resistance of acrylic coating as compared to neat acrylic resin and acrylic/unmodified silica nanocoating. The MPTS modified nanosilica has the potential to be applied as a reinforcing additive to acrylic emulsion resins to improve its abrasion resistance.

This paper focuses to study on change of some characteristics of high density polyethylene (HDPE) pipes testing in Nghe An province seawater. The investigated characteristics of HDPE pipe before and after testing are structural, morphological, crystal, thermal property and stability. Infrared (IR) spectroscopy, scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) methods were used to evaluate the change in characteristics of PE pipes after 10 testing months in Nghe An province seawater. In addition, the change in weight and tensile properties of PE pipes after testing was also investigated. The obtained results showed that the Nghe An province seawater had an influence on the structural, morphological, tensile, crystal and thermal characteristics of PE pipes.

The effects of Seanine 211 content rate on Cu releasing as well as coating properties were investigated. The process of releasing Cu has been studied in dynamic conditions with Seanine content of 0, 3, 5, 10 % and static conditions using Seanine content of 5 % (in weight). Under dynamic conditions, the Cu shall release at high speed in the first 2 days of the test, then remain stable and proportional to the time according to the linear‐line equation, maintained at ≈ 3.5 μg/cm2/day. Under static conditions, the process of Cu releasing is studied through the reduction of coating thickness, the results show that the coating abrasion rate is also proportional to the time and according to linear‐line equation. With the content of 20 % Cu2O (in proportion) and 5 % Seanine (in proportion), the coat has the following properties: relative hardness 0.5; impact resistance 65 Kg.cm; flexural strength 1 mm; adhesion cross cut at 1.

The effect of diane-epoxy resin (DE) and poly(tetrahydrofuran) divinyl ether (DVE) content on the photo crosslinking reaction of the DE/DVE system with triarylsulfonium salt (TAS) as photo-initiator were investigated. The results showed that increasing DVE content improved some of physico-mechanical properties of photocrosslinked coatings although the relative hardness and the speed of photocrosslinking reaction reduced. The results of the changes of functional groups, relative hardness and gel fraction as well as the physico-mechanical properties of UV-cured coatings based on DE/DVE/TAS system illustrated that suitable mass ratio of constituents was 80/20/5. The UV-cured coating based on the system DE/DVE/TAS = 80/20/5 cross-linked completely after 3.6 seconds UV-exposure and having good physico-mechanical properties: impact resistance reached 180 kg.cm; the flexibility obtained 1mm; the adhesion and relative hardness were point 1 and 0.7, respectively.