Morphology aliphatic polyesters

H. Tsuji and Y. Ikada, Blends of aliphatic polyesters, i. physical properties and morphologies of solution-cast blends from poly(DL-lac-tide) and poly(f -ca prolactone),. Appl. Polym. Sci., 60(13) 2367-2375, June 1996. 

Tsuji, H., Yamada, T, Suzuki, M. and Itsuno, S. (2003) Blends of aliphatic polyesters VII. Effects of poly(L-lactide-co-e-caprolactone) on morphology, structure, crystallization, and physical properties of blends of poly(L-lactide) and poly(s-caprolactone). Polymer International, 52, 269-275. 

Tsuji H., Muramatsu H., Blends of aliphatic polyesters. IV. Morphology, swelling behavior, and surface and bulk properties of blends from hydrophobic poly(L-lactide) and hydrophUic poly(vinyl alcohol), J. Appl. Polym. ScL, 81, 2001, 2151-2160. 

The hydrolytic degradation behaviour of aliphatic polyesters depends on many factors such as matrix morphology, stereocomplexation, PLA configuration, chemical composition, size and porosity, dmg loading, etc. (Li, 1999,2006 Li and Vert, 1999). The influence of the factors on the degradation is discussed in the following sections. 

Yamazaki S, Itoh M, Oka T and Kimura K (2010) Formation and morphology of shish-like fibril crystals of aliphatic polyesters from the sheared melt, Eur Polym J 4fi 58-68. 

Wang X, Luo X, Wang X. Study on blends of thermoplastic polyurethane and aliphatic polyester morphology, rheology, and properties as moisture vapor permeable films. Polym Test 2005 24(1) 18-24. 

Pulsed n.m.r. has been used to study morphology of linear aliphatic polyesters and i.r. has been employed for crystal structure studies on poly(ethylene 2,6-naphthalate). Polyfbutylene adipate) and poly(teiephthalates) of bis(4-hydroxy-3-chlorophenyl)-2,2 -propane have been similarly studied. 

Another unique approach toward low 6 is to disperse fine foams in PI films, since the e of air is unity. This technique developed by Hedrick et al. [208] typically involves the preparation of PS-PAA-PS (PS polystyrene) triblock copolymer, imidization, and finally higher temperature annealing where thermally labile PS block undergoes thermolysis (depolymerization) to form submicron pores. They utilized a variety of other thermally unstable block such as poly(a-methylstyrene), poly(propylene oxide), PMMA, poly(e-caprolactone), and aliphatic polyesters and examined the effects of chemical structure, fraction, and molecular weight of the block on the resultant morphology (pore size, shape, porosity) and dielectric and thermal, and mechanical properties. In this case, the resulting porous structure depends on the initial microphase separation domain structure of the thermally labile triblock. For example, nano-foamed PI (19% porosity) prepared from triblock consisting of PMDA-3F [3F = l,l-bis(4-amino-phenyl)-l-phenyl-2,2,2-trifluoroethane] (see Fig. 62 for its structure) and poly(propylene oxide) showed a considerably lower e = 2.3) than that of the non-porous homo PMDA-3F e = 2.9) [209]. 

Researchers at Michigan State University have patented the use of aliphatic polyester-grafted starch as a compatibiliser between starch and aliphatic polyesters such as PCL [86]. These grafted compatibilisers provide enhanced interfacial adhesion between the starch and polyester phases. Compositions with two phases can be generated with a variety of morphologies that affect the properties of the blend. Interfacial adhesion is one factor... 

Effects of Environment on Morphology of Aliphatic Polyesters in Inclusion Compounds... 

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