Novel Unsaturated AliphaticPolyesters: Synthesis,Characterization, and Properties of Multiblock Copolymers Composingof Poly(Butylene Fumarate) and Poly(1,2-Propylene Succinate).

Widespread application of biodegradable polyesters isrestrainedby various disadvantages such as inadequate thermomechanical properties,high cost, and lack of reactive sites for further modification. Poly(butylenefumarate) (PBF), as a novel and low-cost aliphatic polyester, possessesgood physical properties and reactive double bonds along with thepolymer backbones which can be potentially modified to endow the polyesterwith specific properties. However, the biodegradation rate of PBFis too slow to meet the requirement of practical application. In thiscontribution, amorphous poly(1,2-propylene succinate) (PPS) was copolymerizedwith PBF to decrease the crystallinity (Xc) and accelerate the biodegradability of PBF via chain-extensionwith diisocyanate. The chemical structures of the copolymers wereconfirmed by 1H NMR spectra and gel permeation chromatography(GPC). The crystal structure and physicochemical properties were investigatedby wide-angle X-ray diffraction (WAXD), differential scanning calorimetry(DSC), mechanical testing, and enzymatic degradation in detail. Boththe impact strength and degradation rate of the copolymers are effectivelyimproved by the introduction of amorphous PPS; while the melting point(Tm) and crystallization temperature (Tc) are hardly reduced by the incorporation ofPPS. The novel polymer may be directed used as low-cost biodegradablematerials or be further functionalized with special properties forparticular applications. [ABSTRACT FROM AUTHOR]