Grafting behavior of n‐butyl acrylate onto poly(butadiene‐co‐styrene) latexes

J. Polym. Sci. A Polym. Chem.

Yang

Scott

et al. 2012

The central challenge that has limited the development of catalytic hydrogenation of diene-based polymer latex (i.e., latex hydrogenation) in large-scale production pertains to how to accomplish the optimal interplay of accelerating the hydrogenation rate, decreasing the required quantity of catalyst, and eliminating the need for an organic solvent. Here, we attempt to overcome this dilemma through decreasing the dimensions of the polymer substrate (such as below 20 nm) used in the hydrogenation process. Very small diene-based polymer nanoparticles were synthesized and then used as the substrates for the subsequent latex hydrogenation. The effects of particle size, temperature, and catalyst concentration on the hydrogenation rate were fully investigated. An apparent firstorder kinetic model was proposed to describe the rate of hydrogen uptake with respect to the concentration of the olefinic substrate (C¼ ¼C). Mass transfer of both the hydrogen and catalyst involved in this solid (polymer)-liquid (water)-gas (hydrogen) three-phase latex system is discussed. The competitive coordination of the catalyst between the C¼ ¼C and acrylonitrile units within the copolymer was elucidated. It was found that (1) using very small diene-based polymer nanoparticles as the substrate, the hydrogenation rate of polymer latex can be

Section: Resultsmentioning

confidence: 99%

Organic solvent‐free catalytic hydrogenation of diene‐based polymer nanoparticles in latex form. Part II. Kinetic analysis and mechanistic study

J. Polym. Sci. A Polym. Chem.

Yang

Scott

et al. 2012

“…The crosslinking was estimated using a solvent extraction technique, which has been described in detail in El‐Aasser and coworkers' reports . Briefly, a certain amount of dried latex film of SBR was first cast and then mixed with acetone for 24 h. Subsequently, the mixture was subjected to centrifugation at 20,000 rpm for 30 min at ambient temperature.…”

Section: Methodsmentioning

confidence: 99%

Preparation of poly(styrene‐co‐butadiene) fine latex via a gemini surfactant‐induced low‐temperature initiation semibatch emulsion polymerization system

J. Polym. Sci. Part A: Polym. Chem.

Chan

Bregu

et al. 2016

A low‐temperature semibatch emulsion polymerization process to synthesize styrene butadiene rubber nanosized particle latex is presented. Because this polymerization system is initiated and polymerized at an ambient temperature of 25 °C, reductions in the expensive capital cost associated with the heat/cooling system during polymerization are achieved. This system shows potentially significant implications for the latex manufacturing industry.

“…The gel fraction measurements were carried out by use of a solvent extraction technique, the details of which have been described [15]. Briefly, 0.2 g of dried film of hydrogenated NBR was first cast and then mixed with 25 ml chlorobenzene for 24 h. The dissolved portion is determined gravimetrically from the amount of solids remaining in the supernatant after the centrifugation of the mixture system at 10000 rpm for 30 min.…”

Section: Gel Fraction Measurementsmentioning

confidence: 99%

RuRh Bimetallic Nanoparticles Stabilized by 15-membered Macrocycles-terminated Poly(propylene imine) Dendrimer: Preparation and Catalytic Hydrogenation of Nitrile–Butadiene Rubber

Peng

2014

Nano-Micro Lett

Abstract:A new fourth-generation poly(propylene imine) dendrimer (G4-M) containing 32 triolefinic 15-membered macrocycles on the surfaces has been synthesized. The bimetallic RuRh dendrimer-stabilized nanoparticles (DSNs) were first prepared within G4-M by a co-complexation route. The new G4-M dendrimer has been characterized by 1H nuclear magnetic resonance, infrared radiation, and elemental analysis. The dendrimer-stabilized bimetallic ions and reduction courses were analyzed by UV-vis spectroscopy. Highresolution transmission electron microscopy and energy dispersive spectrometer were used to characterize the bimetallic nanoparticle size, size distribution, and particle morphology. The RuRh bimetallic DSNs showed high catalytic activity for the hydrogenation of nitrile-butadiene rubber.