• 作者： 張銘遠; 范記彰
• 作者服務機構： 國立中央大學理學院
• 中文摘要： 纖維素在不均勻的反應條件下被切割，其分子崩解之狀況深受晶體結構因素的影響。本實驗使用醇解及氣態鹽酸試劑分解纖維素，然後利用G.P.C.以測定其分子量分佈狀態(MWD)，獲致了上述的結論。 對天然纖維分子量分佈狀態的分析，佐證了纖維素分子係由長度為1,000 DP之基本單位所組成的學說。 天然纖維素經醇解後，絕大部分的分子斷裂成長度為LODP的片段。一小部份被「自由切割」生成一連串的小分子。其MWD曲線因而呈現為一個主峰，附帶一條延伸到6DP之長尾。鹼化處理後再經醇解之纖維素，其原來之LODP減短，生出許多中間長度的小分子，而被「自由切割」所造成的小分子之數量亦有相當的增加，因此引致MWD曲線上的一個肩狀突起。經過無水鹽酸氣分解試驗的求證以後，判定此一突起實係醇解實驗之假象。 本責驗亦發現無水鹽酸氣崩解識維素之能力很強，頗有繼續研究之價值。
• 英文摘要： The heterogeneous degradation of celluloseis influenced by the structural factors of thecrystal. The present experiment comes to thisconclusion on the evidence of the methanolysisand the gas phase degradation of cellulose,followed by the GPC analysis of the molecularweight distribution (MWD) of the correspondingmaterial. The analysis of the MWD of several nativecelluloses has verified the theory of a 1,000 DPbasic molecular structure for cellulose. After methanolysis, the major part of thecellulose molecules are broken down into frag-ments of an average length measured by LODP.A small fraction of the molecules, at the meantime, are cut by a random scission to producea continuous series of small oligomers. TheMWD curve is therefore appeared as a majorpeak at LODP and a long tail extending downto 6 DP. Upon mercerization of cellulose, theoriginal LODP is reduced, a fair amount ofintermediate sized molecular fragments are gen-erated, and the fraction of oligomers is alsoenhanced. As a result, there appears a shoulderin the low molecular weight side of the MWDcurve implicating the possibility of a secondarystructural unit in the crystal. When we examinethis question more closely with the gas phasedegradation, it is evident that such a shoulderis an artifact of the methanolysis expeirment.
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