Glucosamine oligomers: 4. Solid state-crystallization and sustained dissolution.
When glucosamine oligomers are stored in the solid state they undergo a process of crystallization. The extent to which this occurs depends on whether the samples are isolated in the -NH3+ or -NH2 form, on the storage time, and on the degree of polymerization of the isolated oligomer. The allomorph obtained by this process seems to correspond to the so-called 'tendon-chitosan'. Dissolution of such aged oligomer samples gives rise to a process of dissociation of the associated chains in the crystal, leading to the establishment of a pseudo-equilibrium between single and associated oligomer chains and hence the simultaneous presence of the 'monomeric', 'dimeric', 'trimeric', etc., forms of the oligomer. The phenomenon cannot be attributed to a process of aggregation in solution. The effects of various parameters on this behaviour have been investigated.
Domard
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Laboratoire d'Etudes des Matériaux Plastiques et des Biomatériaux, URA CNRS no. 507, Université Claude Bernard Lyon I, Villeurbanne, France.
Cartier
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D002845:Chromatography; D003460:Crystallization; D005944:Glucosamine / Q000737:chemistry*; D007700:Kinetics; D011108:Polymers / Q000737:chemistry*; D012996:Solutions
D011108:Polymers; D012996:Solutions; D005944:Glucosamine