Radiation Induced Solid-State Polymerization of Acetylenedicarboxylic Acid

Abstract

Radiation induced solid-state polymerization of acetylenedicarboxylic acid was carried out at room temperature in open atmosphere and under vacuum conditions. The gray colored powder polymer obtained was insoluble in most common solvents but only partially soluble in DMSO and THF. The limiting conversion to polymer was about 5%. The polymer was characterized by IR, UV, DP-MS, DSC, TGA, and XRD. The mechanism of polymerization was elucidated from the available data. Polymerization followed a free radical mechanism. However, before the addition of monomer molecules to the growing chain, at least one of the carboxylic groups of the monomer breaks away as CO or CO 2 . The formation of side group cyclization takes place. At least one of the bonds in the side cyclic group is an etheric bond. The DSC, TGA, and XRD results showed that the polymer was partially crystalline and showed no melting up to 1200 C. The mechanism of polymerization and assigned chain structure was studied by the direct pyrolysis mass spectrometric method.The crystal structure of monomer and polymer was investigated by the XRD method. Both monomer and crystalline polymer were monoclinic with similar cell parameters. Thus, the polymerization follows a topotactic mechanism. The unpolymerized monomer retains its crystal Downloaded by [DUT Library] at 12:28 06 October 2014 structure and, therefore, CO or CO 2 in the monomer molecule has to be eliminated before polymerization could take place.

Reaction of Acetylenedicarboxylic Acid Made Easy: High-Pressure Route for Polymerization

“…Usanmuz et al attempted solidstate polymerization of ADCA by irradiating it with Co-60 γrays. 5 No polymer was formed in the first 100 h over which the sample was exposed to a radiation dose of approximately 2 Mrad. They were able to convert about 5.5% of monomer to polymer by increasing the total dose of γ-rays to 70 Mrad; however the molecular weight of the polymer was not calculated.…”

Synthesis and Characteristics of Acetylenedicarboxylic Acid Salts as Precursors for Obtaining of Nanocomposites

“…Some authors show interest to the synthesis and structure of different acetylenedicarboxylic acid salts.There is information aboutcobalt, nickel,2 calcium, magnesium,3 lead4 and other acetylenedicarboxylic acid salts. Also there are studies on solid state polymerization of acetylenedicarboxylic acid,5 its cadmium6 and potassium7 salts. The polymers and polymerization are learned much less than monomers.…”

Crystalline Fully Carboxylated Polyacetylene Obtained under High Pressure as a Li-Ion Battery Anode Material

“…However, it is difficult to obtain through traditional catalytic synthesis using Ziegler–Natta or other transition metal catalysts, − because of the electronic and steric effects of the carbonyl groups and inactivation of the catalyst by an acidic proton. , Only the MoCl 5 –Ph 4 Sn catalyst was reported to catalyze the polymerization of acetylenedicarboxylic acid (ADCA, C 4 H 2 O 4 ), with a yield of only ∼13% and a molecular weight much lower than 2000 . γ-Irradiation was also explored to initiate the polymerization of solid ADCA, but this gave an only 5.5% yield and led to degradation upon overexposure …”

“…18 γ-Irradiation was also explored to initiate the polymerization of solid ADCA, but this gave an only 5.5% yield and led to degradation upon overexposure. 19 High pressure is a robust method for initiating the polymerization of substituted alkynes and producing conductive carbon backbones with the initial composition maintained. 20−25 Even the CC 2− anions in CaC 2 26 and Li 2 C 2 27,28 can polymerize under high pressure, accompanied by a 10 9 -fold enhancement in conductivity.…”