Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Abstract

SYNOPSISVarious homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, 13C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo-and copolymers, as expected. 0 1993 John Wiley & Sons, Inc.

Synthesis and characterization of styrene-acrylic ester copolymers

“…This low value and the constancy indicate the polymers were not crosslinked. 26 The entropies of activation of the viscous flow (⌬S vis ) were also low and positive-22 Ϯ 1 J mol Ϫ1 K Ϫ1 , indicating the polymer structures were reasonably ordered in 1,4-dioxane. Therefore, the ⌬G vis values can be computed and were found to decrease with an increase in temperature.…”

“…But the molar volume of a polymer solution is an enigma; hence, the molar volume of the solvent was used in the calculations because the densities of the polymer solution and of the solvent are generally the same. 26 The other quantities have their usual meaning. This equation can be rewritten as ln͑V/Nh͒ ϭ ͑⌬H vis /RT͒ Ϫ ͑⌬S vis /RT͒ (12) where ⌬H vis and ⌬S vis are the enthalpy and entropy of the viscous flow.…”

Tailoring the swelling and glass‐transition temperature of acrylonitrile/hydroxyethyl acrylate copolymers

“…The chemical structures of the copolymers were confirmed by FTIR study. Also, the band intensity ratios of carbonyl to nitrile increased in the following order: PAN(92)-co-PHEA(8) to PAN(88)-co-PHEA (12) and PAN(84)-co-PHEA (16). Figure 3 shows the 1 H-NMR spectra of random PAN-PHEA copolymers at various molar ratios.…”

“…T g values of the copolymers of PAN and polyacrylates have been reported in many studies. [16][17][18] However, none of the previous reports have ever issued the T g of the PAN-PHEA copolymer. The T g of the copolymers was between those of the homopolymers of PHEA (T g ¼ 3.5 C) and PAN (T g ¼ 104 C).…”

“…The study showed that the thermal characteristics were affected by the weight percentage of the comonomer, as observed earlier for comparable systems. 13,16,19,20 The thermogravimetric analysis (TGA) thermograms of the synthesized copolymers and homopolymers are shown in Figure 6. There were two degradation steps for pure PAN, namely, cyclization and aromatization of the polymer by the release of HCN.…”