Synthesis of Hyperbranched Poly(ester amide)s and Their Application in Polycarbonate as Rheological Modification Agent
Due to highly branched three-dimensional sphere-like molecular architecture,hyperbranched polymers have shown very different properties such as intramolecular cavities,low viscosity,high solubility and a large number of terminal functional groups if compared with their linear analogues.They can be facilely synthesized via a one-pot polymerization through different methods according to the type of monomers,including polycondensation of ABn monomers,self-condensing vinyl polymerization,self-condensing ring-opening polymerization and so on.Here,hyperbranched poly(ester amide)s (HBPEAs) with terminal carboxyl groups are prepared from benzene-1,2,4-tricarbonylic acid-1,2-anhydride (BTAA) and ethanolamine (EMA) via two-step and one-step melt polycondensation,respectively.In two-step method,the anhydride group in BTAA first reacted with the amino group in EMA to form a AB2 intermediate with one hydroxyl groups and two carboxyl groups in ethanol according to the principle of non-equal reactivity of functional groups.After ethanol evaporated,the AB2 intermediate was melted at 220 ℃ to polymerize to produce HBPEA without gelation.Furthermore,HBPEA was also synthesized from BTAA and EMA at 220 ℃ through one-step melt polycondensation,more convenient in the industry.The resulting HBPEAs were characterized by 1H-NMR analysis,Ubbelohde viscometer,differential scanning calorimeter (DSC),thermo gravimetric analyzer (TGA) and refractive index measurements,their DBs are about 0.64 and intrinsic viscosities are about 0.120 ～ 0.146 dL/g.Their Tgs are about 125 ℃ and refraction indexes are about 1.57 ～ 1.58,which is similar to those of PC.The temperature of 5 wt％ weight loss is above 350 ℃.Therefore,HBPEAs can be used as modification agent to process polycarbonate.When HBPEAs were added into PC or PC/CaCO3,not only the process ability of PC or PC/CaCO3 was improved,but also the colour of PC was kept unchanged.In addition,the mechanical properties and the surface roughness of PC or PC/CaCO3 were enhanced too.In summary,HBPEAs have very broad prospects for different applications.
NETL
NSTL
万方数据
维普
