Three biphenyl (I, II, III) compounds and a benzylarylether (IV) compound were synthesized to detect and quantify the presence of phenolic phenylpropenols in unbleached, peroxide-bleached, or sodium borohydride-reduced mechanical softwood pulps. The methodology used is based on a gas chromatography mass spectrometry search of the prepared compounds in the residue obtained after ethylation, thioacidolysis, and desulfurization of the pulps. Detection of biphenyl I ([Formula: see text]4 × 106 mol g1) in unbleached and NaBH4-reduced pulps is indicative of the presence of phenolic coniferaldehyde units in these pulps. Traces of biphenyl II, found in the peroxide-bleached pulp, probably came from ferulic acid units formed by oxidation of coniferaldehyde by H2O2. No biphenyl ether III or benzylaryl ether IV were detected in the three pulps. This result indicates that phenolic phenylpropenol units are not present in softwood mechanical pulps and do not contribute to the fast part of their photoyellowing.Key words: mechanical pulp, photoyellowing, phenol, coniferyl alcohol, biphenyl.
合成了三种
联苯(I、II、III)化合物和一种苯基芳基醚(IV)化合物,用于检测和定量未漂白、过氧化漂白或
硼氢化钠还原的机械软木浆中
酚基苯
丙烯酚的存在。所使用的方法基于对经乙基化、
硫酸酯解和
硫脱
硫后获得的残渣中的制备化合物进行气相色谱-质谱搜索。在未漂白和NaBH
4-还原的浆中检测到的
联苯I([Formula: see text]4 × 10
6 mol g
1)表明这些浆中存在
酚基考酮醛单元。在过氧化漂白浆中发现的微量
联苯II可能来自于对考酮醛通过H
2O
2氧化形成的
香豆酸单元。在这三种浆中未检测到
联苯醚III或苯基芳基醚IV。这个结果表明机械软木浆中不存在
酚基苯
丙烯酚单元,也不会对其光黄变的快速部分产生影响。关键词:机械浆、光黄变、
酚、考酮醇、
联苯。