Synthesis Of Castor Oil Bio-based Polyesters Via PROP

We present here the synthesis of bio-based polyesters and bio-based multi-block copolymers by using the in situ cascade polycondensation-coupling ring-opening polymerization(PROP)method with castor oil-based monomers.Including:1)Synthesis and properties of poly(butylene-co-decylene terephthalate)(PBDT);2)Synthesis and properties of multi-block copolyesters(PEB4-b-PEO45-b-PEB4)m based on polyoxyethylene and polyethylene brassylate.Detailed contents are outlined as following:(1)Synthesis of PBDT copolyesters by using cyclic oligo(butylene terephthalate)(COBTs)as monomer and castor oil-based 1,10-decanediol as initiator.The structure is confirmed by 1H quantitative NMR and two dimensional NMR spectra.A series of performance studies on thermogravimetric analysis,differential scanning calorimetry,dynamic mechanical analysis and tensile testing.Studies have shown that the melting point,glass transition temperature,storage modulus,and Young’s modulus of the copolyester decrease with the increase of the bio-based diol content.The strain increases in turn.Bio-based copolyesters have lower processing temperatures and better toughness than PBT.(2)An aliphatic amphiphilic multi-block copolymer having PEO as a hydrophilic segment and PEB as a hydrophobic segment was synthesized by using castor oil-based ethylene brassylate(EB)as a monomer and PEO as a macroinitiator.The molecular weight of the product was determined by gel permeation chromatography.A series of performance studies on thermogravimetric analysis.differential scanning calorimetry,tensile testing,degradation and self-assembly.Studies have shown that multi-block copolymers have good thermal stability.Multi-block copolymers are stable at room temperature and below neutral conditions;they are significantly degraded in the presence of lipase.The above amphiphilic multi-block copolymer can self-assemble to form micelles in water,and under other conditions,the particle size decreases as the number of blocks increases,and becomes larger as the concentration increases.