A method was developed for the isolation of tissue fractions from the middle lamella and secondary wall of black spruce (Picea mariana) tracheids. The concentrations of cellulose and glucomannan were found to be lower in the middle lamella tissue than in the secondary wall tissue, while the reverse was found for galactan and arabian. The content of glucuronoarabinoxylan was essentially the same in both morphological areas. The concentration of phenolic hydroxyl groups in the lignin in the two tissue fractions was determined by turbidimetric spectrophotometry and by pyrolytic gas chromatography. Secondary wall lignin was found to contain more than twice as many phenolic hydroxyl groups per phenylpropane unit as middle lamella lignin. The concentration of methoxyl groups in secondary wall lignin was 1.6 times the concentration in middle lamella lignin, indicating that about 40% of the lignin polymer in the middle lamella consisted of para-hydroxyphenyl residues. Most of the carbonyl groups in the lignin in wood were found in the middle lamella lignin. The carboxyl content of the middle lamella was about three times that of the carboxyl content of the secondary wall. Secondary wall lignin was more reactive towards chlorine, chlorine dioxide and sodium bisulphite. Secondary wall lignin was also more quickly dissolved than middle lamella lignin in kraft, acid-sulphite, and acid-chlorite pulping. The activation energies, towards kraft pulping, of middle lamella and secondary wall "bulk" lignin were found to be essentially the same. However, it was discovered that while most of the secondary wall lignin followed first order reaction kinetics, 70% of middle lamella lignin did not. It was also discovered that the majority of milled wood lignin originated in the secondary wall of the tracheid.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.68721 |
| Date | January 1981 |
| Creators | Whiting, Philip. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemistry) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000138855, proquestno: AAINL10292, Theses scanned by UMI/ProQuest. |
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