Properties of solutions of poly‐N‐vinylcaprolactam

Abstract

SynopsisThe properties of poly-N-vinylcaprolactam organic and aqueous solutions were studied.Aqueous solutions present a very accentuated diminishing of [ q ] from 10 to 30°C. Above 30°C. the polymer precipitates from ita aqueous solutions. The precipitation temperature does not depend on the concentration but on the molecular weight of the polymer. Some acid and basic agents have a marked inhence on [q] and the precipitation temperature of the aqueous solutions.Toluene solutions present an increasing [?] from 10 to 40°C.There are no studies about the behavior of poly-N-vinylcaprolactam solutions. It is only known that some poly-N-vinyllactams precipitate with heat from their aqueous solutions.The temperature at which the precipitation phenomenon appears is dependent on the number of C atoms of the lactamic ring: for po1y-Nvinylcaprolactam this temperature is about 35°C. and for poly-N-vinylpiperidone it is 64-65OC.lIn the case of poly-N-vinylpyrrolidone such a precipitation does not take place in the usual temperttture range (O--lOO°C.). It was admitted that this abnormal phenomenon is due to the colloidal nature of aqueous solutions of poly-N-vinyllactams,2 and it was supposed that the increasing temperature diminishes the polymer ~olvation.~ The object of the present work was the study of the behavior of po1y-Nvinylcaprolactam solutions from the viewpoint of their viscosity and of the factors that influence the temperature at which the polymer precipitates from its aqueous solutions.

Synthesis and characterization of a novel N-vinylcaprolactam-containing acrylic acid terpolymer for applications in glass-ionomer dental cements

“…The polymerization of NVC has not been studied as systematically as that of NVP. NVC can be polymerized by a radical mechanism with or without solvent [20]. NVC polymers have attracted much attention due to their thermosensitivity and biocompatibility.…”

“…NVC polymers have attracted much attention due to their thermosensitivity and biocompatibility. Due to the fact that hydrolysis of the amide group of NVC will not produce small amide compounds, NVC is suitable for biomedical applications [14][15][16][17][18][19][20].…”

Miscibility of polystyrene with poly(ethylene oxide) and poly(ethylene glycol)

“…known concentration might be used to give [ h] (8) at infinite dilution of the solution (that is, directly. A number of equations [35][36][37][38][39][40][41][42][43][44][45] have been when c approaches zero).…”

Approaches to Chemical Synthesis of Protein-Like Copolymers

“…Such a length is too short to cause pronounced heatinduced phase separation effects typical for the thermoresponsive NVClcopolymers. However, the phase transition for such thermally precipitating fractions started at the temperatures 33-44 • C, i.e., in the region of T cp values characteristic of the NVCl-homopolymers (32-45 • C, depending on the polymer molecular weight [28,30,31,33,34]). Therefore, it can be assumed that all the NVCl/NVIAz-copolymers of the o-and p-types were not the random copolymers with the short oligoNVCl segments.…”