Novel Network Polymeric Phthalocyanines: Synthesis and Characterization

Synthesis and Characterization of ABA-Type Triblock Copolymers Using Novel Bifunctional PS, PMMA, and PCL Macroinitiators Bearing p-xylene-bis(2-mercaptoethyloxy) Core

Syntheses of novel bifunctional poly(methyl methacrylate) (PMMA)-, poly(styrene) (PS)-, and (poly ε-caprolactone) (PCL)-based atom transfer radical polymerization (ATRP) macroinitiators derived from p-xylene-bis(1-hydroxy-3-thia-propanoloxy) core were carried out to obtain ABA-type block copolymers. Firstly, a novel bifunctional ATRP initiator, 1,4-phenylenebis(methylene-thioethane-2,1-diyl)bis(2-bromo-2-methylpropanoat) (PXTBR), synthesized the reaction of p-xylene-bis(1-hydroxy-3-thia-propane) (PXTOH) with α-bromoisobutryl bromide. The PMMA and PS macroinitiators were prepared by ATRP of methyl methacrylate (MMA) and styrene (S) as monomers using (PXTBR) as the initiator and copper(I) bromide/N,N,N',N″,N″-pentamethyldiethylenetriamine (CuBr/PMDETA) as a catalyst system. Secondly, di(α-bromoester) end-functionalized PCL-based ATRP macronitiator (PXTPCLBr) was prepared by esterification of hydroxyl end groups of PCL-diol (PXTPCLOH) synthesized by Sn(Oct)2-catalyzed ring opening polymerization (ROP) of ε-CL in bulk using (PXTOH) as initiator. Finally, ABA-type block copolymers, PXT(PS-b-PMMA-b-PS), PXT(PMMA-b-PS-b-PMMA), PXT(PS-b-PCL-b-PS), and PXT(PMMA-b-PCL-b-PMMA), were synthesized by ATRP of MMA and S as monomers using PMMA-, PS-, and PCL-based macroinitiators in the presence of CuBr/PMDETA as the catalyst system in toluene or N,N-dimethylformamide (DMF) at different temperatures. In addition, the extraction abilities of PCL and PS were investigated under liquid-liquid phase conditions using heavy metal picrates (Ag+, Cd2+, Cu2+, Hg2+, Pb2+, and Zn2+) as substrates and measuring with UV-Vis the amounts of picrate in the 1,2-dichloroethane phase before and after treatment with the polymers. The extraction affinity of PXTPCL and PXTPS for Hg2+ was found to be highest in the liquid-liquid phase extraction experiments. Characterizations of the molecular structures for synthesized novel initiators, macroinitiators, and the block copolymers were made by spectroscopic (FT-IR, ESI-MS, 1H NMR, 13C NMR), DSC, TGA, chromatographic (GPC), and morphologic SEM.

Preparation and properties of poly(aryl ether ketone)-based phthalonitrile conductive composite film

A series of poly(aryl ether ketone) polymers containing phthalonitrile with relatively high molecular weights showed good film formation and toughness to be the good candidate for matrix of functional composites. To develop the application of bisphthalonitrile resins in the conductive composite membrane materials field, the phthalonitrile resin/multiwalled carbon nanotubes conductive composite membranes were prepared by the solution blending method. The conductive composite membranes have low percolation threshold (0.25 vol.%) and excellent conductive properties. With 0.79% weight fraction of carbon nanotubes, the cross-linking membrane shows a great enhancement in mechanical properties. They have the potential to be alternative candidates in the field of high-temperature, conductive composite membrane materials.

Synthesis and thermal properties of high-temperature phthalonitrile polymers based on 1,3,5-triazines

Two kinds of phthalonitrile monomers based on 1,3,5-triazine structure have been synthesized. The chemical structures of the phthalonitrile monomers were characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopies. Differential scanning calorimetric analysis revealed the curing behavior of the monomers. Thermogravimetric analysis suggested outstanding thermal stabilities of the triazine-structured phthalonitrile polymers. Thermal decomposition kinetic analysis indicated that the activation energy of the two phthalonitrile polymers is 205.6 and 152.3 kJ mol−1, respectively. Dynamic mechanical analysis showed that the storage moduli ( E′) are 3.62 GPa and 3.66 GPa, respectively, and glass transition temperatures of both the monomers are higher than 350°C. Postcuring effects were investigated, which showed that more excellent thermal and mechanical properties were achieved with postcuring.