Solid-state polycondensation crystallization

Renzi, C Giorano, D. and Baldi, G., Solid state polycondensation of PET mathematical model for crystallization evaluation, Chem. Fiber Int., 46, 172 (1995). 

It was found meanwhile that nearly every slim unbranched polymer chain, such as poly(trimethylene oxide) [224], poly(l,3-dioxolane) [225], poly(tetramethylene oxide) [226], polyethylene imine) [227], poly(3-hydroxy propionate), poly (4-hydroxybutyrate) and poly(6-hydroxyhexanoate) [228,229], poly(butylene succinate) [229], polyadipates [230], nylon-6 [231], and even oligomers of polyethylene [232], form a-CD ICs with channel structures. In all of these cases, inclusion is a heterogeneous process, since the guest polymer and its CD complex are almost insoluble in water. Therefore, extensive sonication had to be applied to accelerate the diffusion process. The polymer was also dissolved in an organic solvent, e.g., nylon-6 in formic acid, and this solution was added to the solution of a-CD [231], Alternatively, a monomer, such as 11-aminoundecanoic acid, was included in a-CD and polymerized to nylon-11 by solid state polycondensation within the channels of the IC. Thus, the IC of nylon-11 was formed under conservation of the crystal packing [233-235],... 

Moreover, the molecular weight remained around 100 000 Da, being much lower than that of the PLLA obtained by the ring-opening polymerization of Z-lactide. Therefore, they examined the melt/solid polycondensation of lactic acid in which the melt polycondensation of Z,-lactic acid was subjected to solid-state polycondensation below Tm of PLLA [8]. In solid state, the polymerization reaction can be favored over the depolymerization or other side reactions. Particularly, in the process of crystallization of the resultant polymer, both monomer and catalyst can be segregated and concentrated in the noncrystalline part to allow the polymer formation to reach 100% [9]. Figure 3.2 shows the whole process of this melt/solid polycondensation of Z-lactic acid. In this process, a polycondensation with a molecular weight of 20 000 Da is first prepared by... 

Certain polyamides and polyesters can be prepared by solid-state polycondensation step polymerization, usually by heating the appropriate monomer or monomer salt. For example, nylon 11 can be prepared by heating crystals of 11-aminoundecanoic acid (melting point =188 C) at 160°C under vacuum. Polyaddition step polymerization of conjugated dialkene monomers can be induced in the solid state by exposure of the monomer to ultra-violet radiation. For example, irradiation of crystalline 2,5-distyrylpyrazine yields quantitatively a highly crystalline linear cyclobutane polymer... 

Polycondensation reactions starting with the monomer in the solid state have been reviewed by Morawetz [13—15). In these polymerizations the monomer is already restricted to a lattice position and the reaction is often influenced by the crystal structure of the monomer (topochemical reaction). Since it is unlikely that polymerization takes place in the interior of a perfect monomer cr5 tal one assumes that the... 

Polycondensations of aminoacids and oligoamids have led only to successive pol5mierization and crystallization with a loss of the initial orientation. A seeming exception, the poljonerization of e-aminocaproic acid from the solid state which produced oriented pol5mier crystals was shown to be an epitactic pol5nnerization and crystallization (75). Some of the reactions were topochemical since they followed a reaction path only possible from the crystalline monomer, but none of the investigated cases demonstrated a solid state path from the monomer to the polymer crystal. 

A series of cyclic oligosaccharides of even numbers of sugar units, 6-10, built up from (1 4)-linked alternating d- and L-pyranosidic units in a polycondensation-cycloglycosylation reaction has been described. In the solid state. X-ray crystal structure analysis of the cyclic oligosaccharide containing the alternating 1,4-linked a-L-rhamnopyranosyl and a-n-mannopyranosyl residues revealed a nanotube with a diameter of ca. 1 run [177]. 

Du C, Lin SKC, Koutinas A, Wang R, Webb C (2007) Succinic acid production from wheat using a biorefining strategy. Appl Microbiol Biotechnol 76 1263-1270 Fujimaki T (1998) Processability and properties of aliphatic polyesters, BIONOLLE , synthesized by polycondensation reaction. Polym Degrad Stab 59 209-214 Gan ZH, Abe H, Kurokawa H, Doi Y (2001) Solid-state microstructures, thermal properties, and crystallization of biodegradable poly(butylene succinate) (PBS) and its copolyesters. Biomacromolecules 2 605-613... 

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