Competition between Crystallization and Coalescence during the Film Formation of Poly(Chloroprene) Latex and Effects on Mechanical Properties

Abstract

Poly(chloroprene) is a synthetic crystallizable polymer used in several applications, including rubber gloves. The film formation of poly(chloroprene) latex offers opportunities to define structures at length scales between the molecular and macroscopic, thereby adjusting the elastomer's mechanical properties. However, the connections between processing and the resultant film properties are not fully understood. Here, we investigate the competition between the coalescence of latex particles to build cohesive strength and their crystallization to raise the elastic modulus. We demonstrate that when coalescence precedes crystallization, the elastomer has greater extensibility and a higher tensile strength compared to when crystallization occurs during coalescence. The mechanical properties of poly(chloroprene) were tuned by blending two colloids with differing gel contents and crystallizabilities. Heating above poly(chloroprene)'s melting temperature allows increased particle interdiffusion and builds cohesion, prior to recrystallization. We provide evidence from in situ wide-angle X-ray scattering for the strain-induced crystallization of as-cast films from particle blends.

Preface to the Mohamed El-Aasser Festschrift

“…The articles by Keddie et al 21 and Leiza et al 22 are on latex film formation and the properties of the resulting films. Keddie et al 21 investigated the relative influences of latex particle coalescence and polymer crystallization on the mechanical properties of poly(chloroprene) latex films.…”

“…The articles by Keddie et al 21 and Leiza et al 22 are on latex film formation and the properties of the resulting films. Keddie et al 21 investigated the relative influences of latex particle coalescence and polymer crystallization on the mechanical properties of poly(chloroprene) latex films. Leiza et al 22 designed core−shell latex particles containing a semicrystalline poly(stearyl acrylate) core toward application as barrier coatings for steel.…”

Effect of filament types and loops number on the force degradation of elastomeric chains used for orthodontic treatment: an in-vitro study

“…Many studies have investigated the effects of temperature on the force degradation of elastomeric chains. To study the force degradation of elastomeric chains, some researchers simulated the oral temperature and compared it with the normal environment [ 23 , 24 ]. They found that the force degradation increases with temperature at 10 °C, 22 °C, and 37 °C.…”

Changes in crosslinking structure of thermo‐oxidative aging chloroprene rubber and its effect on strain‐induced crystallization

“…During the stretching process, the rubber molecular chains stretched and transition from folded to stretched conformation, resulting in strain‐induced crystallization (SIC) 15–17 . SIC is closely related to the fracture strength and fatigue fracture resistance of rubber 10,18,19 . Elongated crystallites are most likely to form during stretching, and the grains are oriented along the chain axis parallel to the stretching direction, which results in significant changes in the degree of crystallinity and molecular chains orientation of the rubber.…”

“…[15][16][17] SIC is closely related to the fracture strength and fatigue fracture resistance of rubber. 10,18,19 Elongated crystallites are most likely to form during stretching, and the grains are oriented along the chain axis parallel to the stretching direction, which results in significant changes in the degree of crystallinity and molecular chains orientation of the rubber. It is the improvement of orderliness will hinder the fatigue fracture of rubber and significantly increase its fatigue life.…”