聚乙烯醇在階段性熱處理下的結(jié)構(gòu)變化
發(fā)布時(shí)間:2018-06-29 10:21
本文選題:聚乙烯醇 + 階段性熱處理 ; 參考:《高分子材料科學(xué)與工程》2017年05期
【摘要】:聚乙烯醇(PVA)在熱處理作用下會(huì)逐漸發(fā)生側(cè)基脫除、斷鏈、環(huán)化等復(fù)雜的副反應(yīng)。通過(guò)階段性熱處理方法,可望在減少副反應(yīng)的同時(shí)在分子主鏈上生成雙鍵,從而得到類(lèi)似聚乙炔的共軛聚合物。文中以PVA1799為原料,通過(guò)階段性加熱法,利用在線紅外技術(shù),研究了PVA在氮?dú)鈿夥障虏煌瑴囟葻崽幚砗蟮慕Y(jié)構(gòu)變化。熱處理溫度范圍為30~330℃,在150℃,180℃,210℃,240℃,270℃,300℃和330℃每個(gè)溫度點(diǎn)停留30 min。研究發(fā)現(xiàn),PVA的熔點(diǎn)為210℃,在240℃開(kāi)始發(fā)生結(jié)構(gòu)變化,并在分子主鏈生成雙鍵和羰基。當(dāng)溫度超過(guò)300℃,有少量二氧化碳(CO_2)放出,開(kāi)始出現(xiàn)更為復(fù)雜的副反應(yīng)。
[Abstract]:The side group removal, chain breaking and cyclization of polyvinyl alcohol (PVA) will occur gradually under heat treatment. By means of heat treatment, the conjugated polymers similar to polyacetylene can be obtained by forming double bonds at the same time of reducing side reactions. Using PVA1799 as raw material, the structure changes of PVA after heat treatment at different temperatures in nitrogen atmosphere were studied by means of stage heating and on-line infrared technique. The heat treatment temperature ranges from 30 鈩,
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