In situ ring-opening polymerization of hydroxyapatite/poly(ethylene adipate)-co-(ethylene terephthalate) biomimetic composites

Abstract

Hydroxyapatite/poly(ethylene adipate)-co-poly(ethylene terephthalate) biomaterials (HAp/PEA-co-PET) have been prepared by ring opening polymerization (ROP) of cyclic oligo(ethylene adipate)-co-oligo(ethylene terephthalate) (C-OEA-co-C-OET) in the porous hydroxyapatite (HAp) scaffolds at 250 • C for 24 h under vacuum. The content of ROP-PEA-co-PET in the HAp/PEA-co-PET composite was about 20 wt% with the values of number average molecular weight (M n) and weight average molecular weight (M W) of 3380 and 7160 g/mol, respectively. Compressive strength and modulus of the HAp/PEA-co-PET composites were about 29 and 246 MPa, respectively. These mechanical properties were higher than those of the porous HAp templates and natural cancellous bone. In vitro bioactivity of the HAp/PEA-co-PET composites was studied by soaking in simulated body fluid (SBF) under the flowing system at the rate of 130 mL/day for 7, 14, 21 and 28 days. The formation of hydroxyapatite nanocrystals was observed on the composite surfaces through the consumption of calcium and phosphorus from the SBF solution, indicating the bioactivity of these HAp/PEA-co-PET composites. These results indicated the competency of HAp/PEA-co-PET composites for biomedical applications.

Chemical recycling of poly(bisphenol A carbonate)

“…Cyclic ethylene adipate c(EA) n could be successfully Please do not adjust margins Please do not adjust margins prepared in high yields by pseudo-high dilution condensation of adipoyl chloride and ethylene glycol using different organic bases 19 or by CDP of poly(ethylene adipate) in chlorobenzene solution using di-n-butyl tin oxide catalyst. 29,58 The last method was also applied for the synthesis of cyclic decamethylene adipate c(DA) n . 30, 59 c(DA) n from monomer to heptamer were well resolved by GPC, being the first one the predominant species observed after 5 days of CDP.…”

ED-ROP of macrocyclic oligomers: A synthetic tool for multicomponent polymer materials

“…A ceramic filler largely used for mimicking the natural bone system is hydroxyapatite (HAp); while calcium silicate was demonstrated to have a high ability to induce upon soaking in liquid simulating body fluids the fast formation of a HAp layer which can favor bonding with living bone. 115 Composites containing HAp 116,117 or calcium silicate 113 are obtained by ED-ROP of cyclic oligo(ethylene terephthalate) or cyclic oligo(ethylene adipate)-co-oligo(ethylene terephthalate) in the presence of di-n-butyltin oxide catalyst. MCOs were previously obtained from CDP of the corresponding polyesters.…”

“…Different reaction temperatures were tested; 250 °C proved to be the most effective when performing ED-ROP within microporous HAp templates. 117 The bioactivity of the resulting composite constructs was verified by soaking them in simulated body fluids.…”

An efficient cyclodepolymerization route for the chemical recycling of poly(ethylene adipate)

“…[28][29][30][31][32][33][34][35][36][37] The obtained cyclic oligoesters can be used as monomers for ring-opening polymerization (ROP), yielding high molecular weight polyesters that cannot to be synthesized by typical condensation polymerization. [38][39][40][41][42][43][44][45][46] Recently, we developed a cascade polycondensation-coupling ring-opening polymerization (PROP) method, where high molecular weight polyesters with high functional group content can be synthesized via the polymerization of cyclic oligoesters with functional diols, greatly extending the applications of cyclic oligoesters and polyesters. [47][48][49][50][51] Although cyclic monomers can be synthesized by the pseudo-high dilution cyclization (PHDC) of diacyl chlorides with diols, their yields are quite low (20-40%) with large amounts of solvents used.…”