| Summary: | 碩士 === 中原大學 === 化學工程研究所 === 104 === Developing a high-performance barrier films attract more attention due to rapid increase of use in food packaging, pharmaceutical, electrical devices, organic materials and metal components. In this study, we fabricated a graphene oxide (GO)/polyvinyl alcohol (PVA) nanocomposite membrane with different cross-linker by solution coating to obtain high water vapor and oxygen barrier film. The role of cross-linker is to provide more stable for final membrane product. Therefore, we studied the effect of cross-linker structure, concentration and cross-linking time on the water vapor barrier performance.
ATR-FTIR、XPS、degree of swelling, XRD, thermal Analysis, UV-visible and MOCON data were used to identify the degree of crosslinking, transparency, oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) of the barrier nanocomposite membranes. The results of crosslinker structure, degree of crosslinking and degree of crystallinity will be the major parameters which affect barrier performance of the films at the operating environment is 37。C and 70 RH%. More functional groups and high concentration can increase degree of crosslinking but decrease the degree of crystallinity. Crosslinker with high steric hindrance structure makes the film density decrease. Therefore, the three interactions affect the barrier performance. Using the crosslinker of Tricarballylic acid can obtain the highest degree of crosslinking for crosslinked film and it improve the barrier performance about 27.7%. Crosslinker content for 10 mol% improve the barrier performance about 33.3%. And then increase the crosslinking time to 20 hr. It can improve the barrier performance about 54.3% because it have enough reaction time. So that the crosslinking reaction tends to more completely.
Oxygen transmission for crosslinked films on PET substrate are tested at the 37 ° C and 0 RH%. In the study, the crystalline properties of the film dominates the film’s gas barrier properties even if the degree of crosslinking also affect gas barrier properties. High degree of crosslinking decrease the degree of crystallinity, lead to the gas barrier properties decrease. Films maintain the crystalline and partially crosslinked structure which can improve the gas barrier properties. Compared to non-crosslinked film, gas barrier performance increase about 68.5% for the membrane added 5 mol % of tricarballylic acid and crosslinked for 12 hours.
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