Informatics Publishing Limited

HMP. Naveen Kumar ¹, K. Madhusudhana Rao ², M. N. Prabhakar ¹, K. Chowdoji Rao ¹, M. C. S. Subha ²

Affiliations
1 Department of Polymer Science & Tech., Sri Krishnadevaraya University, Anantapur, AP, IN
2 Department of Chemistry, Sri Krishnadevaraya University, Anantapur, A.P, IN

Abstract

The miscibility of Acacia (AC)/Poly (vinyl pyrrolidone) (PVP) and Acacia (AC)/Poly (ethyleneglycol) (PEG) blends in water at 30°C were studied using ultrasonic velocity and density measurements. The results of ultrasonic velocity and the derived acoustical parameters such as adiabatic compressibility (β_ad) and acoustic impedance (Z) have been used to discuss the miscibility/immiscibility of the blends under study. The conclusions drawn from these results indicate that AC/PVP blends are miscible whereas AC/PEG blends are immiscible. The miscible/immiscible nature of these two blends may be attributed to the intermolecular interactions between the constituent polymers. These investigations offer an entirely new and simple approach to study the compatibility of the polymer blends, which is in general obtained by the sophisticated techniques of thermal, dynamic, mechanical and electron microscopic analysis.

Keywords

Miscibility, Acacia (AC), Poly (Vinylpyrrolidone) (PVP), Poly (Ethylene Glycol) (PEG), Density, Ultrasonic Velocity.

Full Text

   

A. V. Ashok Kumar Reddy ¹, C. Venkata Prasad ¹, M. Saraswathi ¹, HMP Naveen Kumar ¹, M. N. Prabhakar ¹, V. Balaji ¹, K. Madhusudhan Rao ¹, B. Yerriswami ², C. Lakshmi Narayana Reddy ², B. Mallikarjuna ², M. C. S. Subha ², K. Chowdoji Rao ¹

Affiliations
1 Dept. of Polymer Science & Tech., S.K. University, Anantapur, A.P., IN
2 Dept. of Chemistry, S.K. University, Anantapur, A.P., IN

Abstract

Chitosan (CS), a polysaccharide, has many industrial applications and its miscibility studies are most useful. Synthetic polymer, poly (ethylene glycol) (PEG) is a subject of current research interest. Hence, miscibility of CS and PEG in aqueous acetic acid solutions has been studied by ultrasonic velocity, refractive index and viscosity techniques at 303.15 K, over a wide range of compositions ranging from 0-100% of CS in CS/PEG blends. The results of ultrasonic velocity and its derived acoustical parameters such as adiabatic compressibility (β_ad), acoustic impedance (Z), relaxation strength (γ_s) and Rao number (R) have been used to discuss the miscibility/immiscibility of the blend under study. These discussions revealed that the blend is miscible up to 40% of chitosan in the blend and beyond this, the blend is immiscible. Using the viscosity data, the interaction parameters ΔB, μ and α were computed and used to discuss the miscibility/immiscibility nature of this blend. The ultrasonic velocity results are further confirmed by viscosity and refractive index results.

Keywords

Chitosan/PEG Blend, Acoustical Parameters, Miscibility, Refractive Index.

Full Text

   

K. G. Neerajakshi ¹, K. S. V. Krishna Rao ², R. Bharathi ¹, A. B. V. Kiran Kumar ¹, M. C. S. Subha ¹, G. Narayana Swamy ¹

Affiliations
1 Department of Chemistry, Sri Krishnadevaraya University, Anantapur, IN
2 Departnent of Chemistry, Sri Sai Baba National PG College, Anantapur, IN

Abstract

The speeds of sound and densities were measured for the binary liquid mixture of ethylene glycol with n-butylamine (NBA), sec-butylamihe (SBA), tertbutylamine(TBA), n-hexylamine (NHA), n-octylamine (NOA) and cyclohexylamine (CHA) over the whole mole fraction range at 308.15 K. From the experimental data various acoustical parameters, such as isentropic compressibility (k_s), intermolecular free-length (L_f), relative association (R_A), acoustic impendence (z), excess isentropic compressibility (K_s^E), excess inter molecular free-length (L_f^E), excess ultrasonic velocity (U^E) and excess acoustic impedance (Z^E) have been calculated. The behavior, of the present binary liquid mixtures is discussed in terms of possible molecular interactions between unlike molecules. The molecular interactions are discussed from the increasing number of methylene groups in amines, branching and cyclic nature of the amines which indicates the presence of AB type of interactions exist in these binary liquid mixtures.

Full Text

   

M. Eswari Bai ¹, M. C. S. Subha ¹, G. Narayana Swamy ¹, K. Chowdoji Rao ²

Affiliations
1 Department of Chemistry, Sri Krishnadevaraya University, Anantapur-515003, IN
2 Department of Polymer Science and Technology, Sri Krishnadevaraya University, Anantapur-515003, IN

Abstract

Densities and ultrasonic velocities of binary mixtures of 2-butoxy ethanol (BEL) with n-butylamine (NBA), sec-butylamine (SBA), tert-butylamine (TBA), n-hexylamine (NHA), n-octylamine (NOA) and cyclo-hexylamine (CHA), at 308.15 K are measured. From these measured values, various acoustical parameters like acoustic impedance (Z), isentropic compressibility (k_s), intermolecular free length (L_f) and relative association (R_A) have been computed. The various excess properties like excess acoustic impedance (Z^E), excess isentropic compressibility (k_s^E), and excess intermolecular free length (L_f^E) have also been computed from the values of densities and ultrasonic velocities. The results have been discussed interms of various interactions present in these mixtures and self associations in the components.

Full Text