Chemistry is an experimental science, Recommanded Product: 110661-91-1, and the best way to enjoy it and learn about it is performing experiments.Introducing a new discovery about 110661-91-1, Name is tert-Butyl 4-bromobutanoate, molecular formula is C8H15BrO2, belongs to esters-buliding-blocks compound. In a document, author is Hu, Lan-Fang.
Synthesis of High-Molecular-Weight Maleic Anhydride-Based Polyesters with Enhanced Properties
The synthesis of high-molecular-weight (MW) polyesters from the copolymerization of maleic anhydride (MA) and epoxides remains a challenge. Herein, we describe the copolymerization of MA with propylene oxide (PO) using a heterogeneous zinc-cobalt(III) double-metal cyanide complex (Zn-Co(III)DMCC), which afforded polyesters with high number-average molecular weights (M(n)s) of up to 82.8 kDa (previous record: 17.0 kDa). Moreover, the polyesters with cis-maleate could be transformed into biodegradable poly(propylene fumarate)s with high M n s via cis-trans isomerization. The key strategy is using excess MA (e.g., MA/epoxide molar ratio: 2-1/1, previously less than 1) and toluene as the solvent. This approach can afford polyesters with an ester content of >99%, restrain the cross-linking reaction of the generated polymers, and promote the separation of products and excess MA. This method was successfully extended to several epoxides to produce a family of high-MW polyesters (M(n)s: up to 152.0 kDa). The resultant MA-derived polyesters exhibit initial decomposition temperatures of up to 311.5 degrees C and significantly improved stress and elongation at break of up to 25.3 MPa and 1573%, respectively. This work provides a facile and atom-economic process for synthesizing high-MW MA-derived polyesters and biodegradable polyesters with the potential for large-scale production, and the polyesters have the potential to be used as biomedical materials and disposable packing materials.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 110661-91-1, in my other articles. Recommanded Product: 110661-91-1.