The Influence of Initiator Concentration on Selected Properties of Thermosensitive Poly(Acrylamide-co-2-Acrylamido-2-Methyl-1-Propanesulfonic Acid) Microparticles

Abstract

Thermosensitive polymers PS1–PS5 were synthesized via the surfactant free precipitation polymerization (SFPP) using 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA), and potassium persulfate (KPS) at 70 °C in aqueous environment. The effect of KPS concentrations on particle size and lower critical temperature solution (LCST) was examined by dynamic light scattering (DLS). The conductivity in the course of the synthesis and during cooling were investigated. The structural studies were performed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), H nuclear magnetic resonance (1H NMR), thermogravimetric analysis (TGA/DTA) and powder X-ray diffraction (PXRD). ATR-FTIR, 1H NMR and PXRD data confirmed the polymeric nature of the material. TGA/DTA curves demonstrated thermal stability up to approx. 160 °C. The effect of temperature on the hydrodynamic diameter (HD) and zeta potential (ZP) were evaluated by dynamic light scattering (DLS) and electrophoretic mobility (EM) in 18–45 °C range. The LCST values were between 30 and 34 °C. HD and polydispersity index (PDI) of aqueous dispersions of the synthesized polymers PS1–PS5 at 18 °C were found to be 226 ± 35 nm (PDI = 0.42 ± 0.04), 299 ± 145 nm (PDI = 0.49 ± 0.29), 389 ± 39 nm (PDI = 0.28 ± 0.07), 584 ± 75 nm (PDI = 0.44 ± 0.06), and 271 ± 50.00 nm (PDI = 0.26 ± 0.14), respectively. At 18 °C the ZPs of synthesized polymers suspensions were −13.14 ± 2.85 mV, −19.52 ± 2.86 mV, −7.73 ± 2.76 mV, −7.99 ± 1.70 mV, and −9.05 ± 2.60 mV for PS1–PS5, respectively. We found that the initiator concentration influences the physicochemical properties of products including the size of polymeric particles and the LCST.

Influence of the Poly(ethylene Glycol) Methyl Ether Methacrylates on the Selected Physicochemical Properties of Thermally Sensitive Polymeric Particles for Controlled Drug Delivery

“…The polymerization process consists of several consecutive elementary reactions, illustrating the stages of transformation of the substrates into products. In line with our previous research [ 29 , 30 , 31 , 32 ], continuous measurements of the conductivity of the reaction mixture during polymerization can provide the necessary data to determine the onset and duration of the individual polymerization steps to be determined.…”

“…Several methods enable us to obtain detailed insight into the physical and chemical properties of the newly developed drug carriers. The electrolytic conductivity of the synthesized systems provides information on the particular stages of polymerization [ 29 , 30 , 31 , 32 ]. The proton nuclear magnetic resonance ( 1 H NMR) and attenuated total reflectance Fourier-transformed infrared spectroscopy (ATR-FTIR) methods confirm the production of the polymerization product.…”

Layering Charged Polymers Enable Highly Integrated High‐Capacity Battery Anodes

“…Further, the peaks at 1038 and 1170 cm −1 confirm the presence of ‐SO 3 H groups in N binders, along with the peak at 623 cm −1 assigned to stretching vibrations of the C‐S group. [ 24 ] Such adsorption peaks of SO 3 H showed a blueshift to 1178 cm −1 and a decrease in intensity, indicating an interaction between ‐SO 3 − and Li + in the electrolyte‐soaked state (N binder‐Li + ). Moreover, even in a state of mixing at a weight ratio of P:N = 1:1, each characteristic peak was preserved.…”

A recoverable magnetic surface ion-imprinted polymer based on graphene oxide for fast and selective adsorption of Ni(ii) from aqueous solution: experimental and DFT calculations

“…28,29 The spectra of IIP and NIP are approximately the same, the band at 1534 cm −1 is due to the bending vibration of N–H in the MBA, 30 and the two bands at 1392 cm −1 and 1040 cm −1 are due to the OSO asymmetric stretching vibration of –SO 3 H in the functional monomer AMPS. 31,32 Comparing IIP before and after Ni( ii ) adsorption, the band of N–H at 1534 cm −1 is weakened and the bands of OSO at 1388 cm −1 and 1038 cm −1 are shifted, so it can be inferred that the adsorption of Ni( ii ) on IIP is due to the coordination interaction of N–H and –SO 3 H with Ni( ii ).…”