Miscibility Behavior of Polyacrylamides Poly(Ethylene Glycol) Blends: Flory Huggins Interaction Parameter Determined by Thermal Analysis

Abstract

<p class="MsoNormal"> <span lang="EN-US" style="font-family:Verdana;">Blends of polyacrylamide—PAM, poly(N</span><span lang="EN-US" style="font-family:Verdana;">-</span><span lang="EN-US" style="font-family:Verdana;">isopropylacrylamide</span><span lang="EN-US" style="font-family:Verdana;">)—PNIPAAm, poly(N</span><span lang="EN-US" style="font-family:Verdana;">-</span><span lang="EN-US" style="font-family:Verdana;">tert-butylacrylamide)—PTBAA, poly(N,N</span><span lang="EN-US" style="font-family:Verdana;">-</span><span lang="EN-US" style="font-family:Verdana;">dimethylacrylamide)—PDMAA and poly(N,N</span><span lang="EN-US" style="font-family:Verdana;">-</span><span lang="EN-US" style="font-family:Verdana;">diethylacrylamide)—PDEAA with poly(ethylene glycol)—</span><span lang="EN-US"> </span><span lang="EN-US"><span style="font-family:Verdana;">PEG were prepared by casting in methanol and water at concentrations of 20 wt%, 40 wt%, 60 wt%, and 80 wt% in PEG. The miscibility of the components was studied by Differential Scanning Calorimetry—DSC. All blend systems are characterized by a single glass transition temperature (</span><i><span style="font-family:Verdana;">T</span>_{<span style="font-family:Verdana;">g</span>}</i><span style="font-family:Verdana;">), close to the </span><i><span style="font-family:Verdana;">T</span>_{<span style="font-family:Verdana;">g</span>}</i><span style="font-family:Verdana;"> of the amorphous component. The Hoffman Weeks method was used to determine equilibrium melting temperature (</span><i><span style="font-family:Verdana;">T</span>_{<span style="font-family:Verdana;">m</span>}</i><span style="font-family:Verdana;">) data. The determination of the melt point depression of the blends allowed the calculation of Flory-Huggins interaction parameter (</span><i><span style="font-family:Verdana;">χ</span></i>_{<span style="font-family:Verdana;">12</span>}<span style="font-family:Verdana;">) of the two polymers in the melt, by using the Nishi Wang equation. The interaction parameters, calculated for all the blends, are slightly negative and close to zero, suggesting a partial miscibility between the components.</span></span> </p

Shape-Encoded Chitosan–Polyacrylamide Hybrid Hydrogel Microparticles with Controlled Macroporous Structures via Replica Molding for Programmable Biomacromolecular Conjugation

“…These results on the meso- to macro-pore formation of PAAm gels with LC PEG porogen are consistent with previous studies, where partial miscibility or immiscibility of the two polymers leads to phase separation during polymerization (i.e., PIPS) with the LC PEG forming uniform or heterogeneous phases. , For example, Swamy et al reported complete immiscibility of PAAm/PEG-6000 or -4000, while Silva et al recently reported partial miscibility with PEG2000. In our study, short chain PEG (MW 400 or 600 Da) did not lead to macropore formation even at high PEG content (data not shown), while LC PEG readily formed large pores at low content, also consistent with previous studies …”

In Silico Screening of Green Plasticizers for Poly(vinyl chloride)

“…However, the plots of χ 12 value with respect to volume fraction of PVC in the Supporting Information show that the χ 12 parameter varies with PVC volume fraction at 300 K for all plasticizers except DOP and succinates. Nevertheless, for the simulated systems, all χ 12 values are obtained negative; this suggests that the molecules exhibit mutual attraction to each other, − and the increasing value shows that the polymer–plasticizer mixture is more thermodynamically miscible . As an example, Figure shows the FH diagram for the DOP/PVC system at 300 and 450 K. While the individual FH diagrams for the rest of the plasticizers are provided in the Supporting Information, it is instructive to compare the behavior of the succinic acid derivatives with different chain lengths at 300 K, as shown in Figure .…”

Modulating matrix‐multicellular response using polysucrose‐blended with poly‐L‐lactide or polydioxanone in electrospun scaffolds for skin tissue regeneration

“…In order to measure the influence of thermodynamic factors on T m , the Flory Huggins parameter (χ) was determined using equilibrium melting point (T me ) derived from a Hoffman‐Weeks plot eliminating the contribution of morphological factors (Supporting Information, Equation S1). The Flory Huggins parameter is a measure of the miscibility of the blends whereby the more negative the Flory Huggins parameter, the more enhanced is compatibility of the blends. T m of PLLA, PDX and their blends were individually plotted against different T c at which they were each isothermally crystallized.…”