Synthesis Of Hyperbranched Poly(Amide-ester) And Its Mixed Rare Earth Oxides Composites

It is very necessarily to carry out the lower cost technics study for the synthesis of hyperbranched polymer (HBP) and its prepolymerized monomer, so as to extending HBP to be applied in large scale in common industry at low cost. Since it might possible descend apply cost to HBP, simplify apply approach for mix rare earth oxides (for short, RE₂O₃, RE = La, Ce, Pr, Nd, etc.) by directly adding into polymer as oxides form, and make full use of rare earth resource, it seems very significant to compound HBP to mix rare earth oxides which are potential functional agent. In such opinions, some work were been done as follows in this paper.A series of AB₂-type-prepolymerized monomer(AB₂^PD,AB₂^MD,AB₂^SD) was rapidly (2 h) prepared at room temperature (28±5℃) using commercially available substituted maleic anhydride (PA:phthalic anhydride, MA: maleic anhydride, or SA: succine anhydride )and diethanolamine (DEA) as raw materials. The feasibility to rapidly synthesize the AB₂ monomer was discussed. A possible amidation reaction mechanism between substituted maleic anhydride and DEA, was also be supposed.By employing toluene-p-sulfonic acid as a catalyzer, a series of hyperbranched poly(amide-ester) (HBPAE^PD, HBPAE^MD, HBPAE^SD,) were successfully synthesized from the prepared AB₂ monomer by solution condensation polymerization through "one-step process" or "pseudo one-step process" (using pentaerythritol as a center core). The processes were carried out at high temperature of 120℃or 130℃for 6 h in air atmosphere (inert protection free) with reduced pressure distillation (0.08-0.096 MPa). The results of FT-IR, UV-Vis, TGA, and intrinsic viscosity testing by Ubbelodhe viscometer showed that the prepared HBPAE^MDs possess three-dimensional configuration with unsaturated conjugate structure, large numbers of branches and numerous terminal hydroxyl groups. These result in their low viscosity, high solubility and thermal stability. Therefor, the synthesis technics was sound which might be apply in large scale low cost produce.Some unsaturated hyperbranched poly(amide-ester)/RE₂O₃ composites (HBPAE^MD/RE₂ O₃s) containg different wt % RE2O3, were synthesized through the in situ solution condensation of AB₂^MD monomer on the surface of RE₂O₃ which were enveloped with AB₂^MD in advance by mechanical stirring. The structure and physico-chemical properties of the composites were examined by FT-IR, UV-Vis, XPS, TG-DTG etc..The results showed that the condensation of AB₂^MD monomer can influence or change the physico-chemical properties of RE₂O₃ while the RE₂O₃ may influence properties of the composite, and that HBPAE^MD/RE₂O₃s have the typical lower intrinsic viscosity property of HBPAE^MD which was polymerized from the same AB₂^MDmonomer and whose thermal stability being availably improve with a few RE₂O₃ complex。 The surface organic modification of ultrafine RE₂O₃ was been studied by compounding HBPAE^SD to RE₂O₃ through the solution condensation polymerization of AB₂^SD monomer which enwrapped the RE₂O₃ particles in advance by mechanical stirring. At the same time a series of HBPAE^SD/RE₂O₃s were obtained, which were later characterized by FTIR, EA, XPS, SEM, XRD, TGA. According to the data of FTIR, EA, XPS and SEM, it was inferred that after the polymerization, the AB₂^SD monomer became organic layer of HBPAE^SD which was coated on the surface of RE₂O₃ particles, and that some HBPAE^SD were chemical graft from the surface of RE₂O₃ particles. The nature of the interface forces between HBPAE ^SD and RE₂O₃ and the reasons for the change to interface physico-chemical properties were also discussed. Data from XRD and TG-DTG indicated that compounding modification was only been carried out on the surface of RE₂O₃ which had no effect on the crystal structure of the RE₂O₃, and that HBPAE ^SDand RE₂O₃ in composite could each other influenced physico-chemical properties. The dispersivity experiment showed that ultrafine RE₂O₃ modified with HBPAE^SD had a better dispersivity capability than the raw RE₂O₃ in polar solvents or feeble polar solvents.HBPAE^SD/RE₂O₃s were employed as stabilizer of PVC to explore their potential functionation. Compared with the commercial stabilizer, HBPAE^SD/RE₂O₃s achieved a better result in thermal stability.