| In recent years, environmental issues, oil and energy issues have become increasingly prominent. People gradually aroused interest in making agricultural by-products into chemical raw materials. Compared with traditional materials, straw is cheap and yield rich. But the most critical is the straw is agricultural waste, renewable and biodegradable. Therefore, reasonable and efficient use of this large number of renewable, biodegradable and inexpensive crop straw resources, to become waste into treasure, has been an important research subject either to academia or industry.This paper studied the reaction which rice straw modified with acetic anhydride. After acetate the main components in rice straw which are cellulose, hemicelluloses and lignin were introduced a certain amount of acetyl group. Acetylation can expand fiber space, weak molecular interaction, damage micro-structure. Through acetylation, rice straw can be molded by heat.This paper discussed on the influence of practical size, dosage of catalyst and reagent, temperature and time to acetate reaction. The results showed that the acetylation would be best, when reaction temperature was 50℃, and the reaction time was 2 h, the dosage of H2SO4, glacial acetic acid and acetic anhydride were 9%, 10 and 3 times to one part of rice straw in weight, respectively. But through FTIR, WAXD, DSC, TG, and NMR detection, it was found that when the modification temperature was a little higher the product got a low pyrolysis temperature. And not was the higher modification degree the better thermoplastic the better. we found that the product would have the best thermoplastic when follow the dosage of reagent which was optimized, and the temperature, time was 35℃24h,respectively. The melt temperature(190℃) was about 40℃lower than the pyrolysis temperature(232℃). It can be pressed to board by heat or cast to film, but either the straw board or straw film was very brittle, they need to be added diethyl phthalate plasticizers to improve flexibility. |
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