Study Of Polymerization Of Konjac Glucomannan With Crylic Acid By Radiation And Properties Of The Product

In this thesis, polymerization of konjac glucomannan and acrylic acid were induced by radiation of ⁶⁰Co-y ray to improve the product's properties. It has been found out that under the conditions of radiation konjac glucomannan and acrylic acid can produce graft polymer which has high water absorbing capacity as well as water preservation capacity. The characteristic of konjac glucomannan gel after radiation has been studied by texture profile analysis and the result showed that the texture of the gel related not only to the ration of konjac glucomannan to acrylic acid but also to the radiation dose. The structure of polymerized products was characterized by SEM, X-RD, FT-IR, Raman spectroscopy and AFM. Effect of the size of gel granules on water absorbing velocity and water releasing velocity was also analyzed.The major research results are as following:1. Determination of the main components of konjac flourThe results indicated that the contents of water, protein, lipid, konjac glucomannan and starch were 4.47%, 3.65%, 3.26%, 78.85% and 4.38% respectively. The other ingredients such as cellulose and ashes were 5.39%. The content of konjac glucomannan(KGM) reached to 95% after purification by ethanol.2. Radiation preparation of the polymerUnder the conditions of nitrogen atmosphere, the optimal reaction conditions were radiation dose 4.14KGy, neutralization degree of acrylic acid 45%, monomer concentration 22.5%. The resulted polymer can absorb water 936 times of its own weight.3. Structural characterization of PKGMAAThe structure of PKGMAA gel was analyzed by means of TPA, SEM, XRD, FT-IR and Raman spectroscopy. It was found out that the macrostructure and microstructure all changed after radiation. 4. Capability test of PKGMAAIt is indicated that different kind of water has different effects on PKGMAA's water absorbing capability: in distilled water, the smaller size of PKGMAA the higher water absorbing capability. On the contrary, in tap water, the smaller size of PKGMAA, the faster it was deposited because the charge in the gel was neutralized by the charge in tap water. Temperature has the more effects on water releasing velocity of the gel. At the centrifuging speed of 4000r/min,8000 r/min,10000 r/min, there is little water that released from the gel.