Sự suy giảm của màng nhựa acrylic nhũ tương primal AC-261 trong môi trường thời tiết nhân tạo

The degradation of the Primal AC-261 water-based acrylic film (AC-261) in the artifical weathering environment has been studied by fourier-transform infrared (FTIR) and ultraviolet - visible (UV-Vis) spectroscopy, microscope and weight loss analysis. The IR and UV-Vis analysis showed that the level of C-H (alkanes) and C-O- (ester) stretchings decreased while O-H, C=O and C=C (alkene) stretchings increased in the artifical weathering testing process by a QUV weathering chamber equipped with UVB-313 fluorescent lamps and operated under wet-cycle conditions of 8 h UV irradiation at 60 °C, followed by 4 h of dark water condensation at 50 °C. After 96 cycles (1152 hours), the film surface had many black spots and weight loss of the film was 18 %

Nghiên cứu ảnh hưởng của xử lý plasma đến độ bám dính của lớp phủ khâu mạch quang trên nền polypropylen. Phần 1. Nghiên cứu ảnh hưởng của xử lý plasma không khí đến tính chất bề mặt polypropylen.

In this work, polypropylene (PP) was treated by air plasma to improve its adhesion properties. The influence of plasma treatment time was studied. As can be showed from results of static contact angle, the air plasma treatment improved significantly hydrophilic property of PP surface - the contact angle was reduced from 109 to 56o, respectively, before and after 3 minutes plasma treatment. In addition, Scanning Electron Microscope (SEM) images showed that after plasma treatment, the morphology of polymer surface saw rougher than before. The results of Fourier Transformed Infrared Spectroscopy (FT-IR) also presented that newly created hydrophilic functional groups (C=O, O-H) on the polypropylene surface caused by plasma treatment. As a result, the lap-shear strengths of PP after plasma treatment were substantially improved. As can be conclude from the results of this study, the suitable plasma treatment time for PP was 3 minutes

Chế tạo vật liệu compozit sinh học trên nền nhựa polyeste không no gia cường bằng sợi nứa có xử lý bổ sung plasma lạnh

After extracting by mechanical (by hand) and machine methods, Neohouzeaua fiber was treated by air plasma at atmospheric pressure with conditions of power 100W, frequency of 17 kHz and different treatment times (from 1 min to 7 min). SE M analyses showed that the fiber surface become rougher after plasma treatment because of the effect of plasma bombardment and etching. The testing on tensile strength and the interfacial shear strength (IFSS) showed that at the optimal treatment time of 4 minutes: the tensile strength of neohouzeaua fiber increased 15.5 percent after air plasma treatment and treated fiber have cleaner surface. IFSS of the treated fiber at 4 minutes increased 51.7% compared with untreated fiber. Unsaturated polyester (USP) resin composites reinforced by neohouzeaua fiber submitted to air plasma treatment and untreated and USP composites reinforced by hybrid neohouzeaua/glass fiber mat were fabricated using a vacuum infusion process (VIP). Mechanical test, SEM and water absorption measurements of the composites have been investigated. These results reveal that atmospheric pressure air plasma treatment is an effective method to improve not only the performance of neohouzeaua fiber but also of UPS-neohouzeaua composites. With hybrid composites with ply-by-ply structure and the content ratio of neohouzeaua/glass of 40/60 (by weight) the received materials has optimal properties, such as tensile, flexural and impact strengths improve 38.9%, 15.5% and 217.5% compare to PC-Neohouzeaua mat, respectively