Synthesis of nanosized ethylene–propylene rubber latex via polyisoprene hydrogenation

Abstract

Nanosized ethylene–propylene rubber (EPM) latex with a particle size of 47 nm was synthesized via an alternative route consisting of isoprene (IP) polymerization followed by hydrogenation. First, the IP monomer was polymerized by differential microemulsion polymerization to obtain polyisoprene (PIP) rubber latex with a particle size of 42 nm. The structure of synthetic PIP was hydrogenated at the carbon–carbon double bonds to produce an ethylene–propylene copolymer by diimide reduction in the presence of hydrazine and hydrogen peroxide using boric acid as promotor. The degree of hydrogenation was determined by proton nuclear magnetic resonance (1H‐NMR) spectroscopy and the structure of the ethylene–propylene copolymer was identified by 13C‐NMR spectroscopy. In nanosized PIP hydrogenation, the hydrogenation level was found to be increased by boric acid addition. An EPM yield of 94% was achieved using a hydrogen peroxide : hydrazine ratio of 1.5 : 1. The EPM produced from PIP has high thermal stability with the maximum decomposition temperature of 510°C and a glass transition temperature of ‐42.4°C close to commercial ethylene–propylene diene rubber. Dynamic mechanical analysis indicated that EPM had a maximum storage modulus due to the saturated carbons domains of the ethylene segments in the polymer chains. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Synthesis and Characterization of Graft Copolymers Poly(isoprene-g-styrene) of High Molecular Weight by a Combination of Anionic Polymerization and Emulsion Polymerization

“…The compositions of graft copolymers were measured by 1 H NMR (Figure a) and 13 C NMR (Figure b) to certify the copolymerization of isoprene and macromonomer. From Figure a, the sharp chemical shifts of methyl protons from trans -1,4 ( d H ), cis -1,4 ( j H ), 3,4-addition ( n H ) and 1,2-addition ( r H ) polyisoprene can be observed at 1.58 and 1.68 ppm. , The peaks at 5.71–5.8 ppm ( s H ) from 1,2-addition are seen in Figure a. The methylene protons of trans -1,4 ( a H , e H ), cis -1,4 ( f H , i H ), and methine protons of 3,4-addition ( l H ) are shown at 1.91–2.19 ppm .…”

“…From Figure 6a, the sharp chemical shifts of methyl protons from trans-1,4 (dH), cis-1,4 (jH), 3,4-addition (nH) and 1,2-addition (rH) polyisoprene can be observed at 1.58 and 1.68 ppm. 27,28 The peaks at 5.71−5.8 ppm (sH) from 1,2-addition are seen in Figure 6a. The methylene protons of trans-1,4 (aH, eH), cis-1,4 ( f H, iH), and methine protons of 3,4-addition (lH) are shown at 1.91−2.19 ppm.…”

Synthesis of Hydrogenated Natural Rubber Having Epoxide Groups Using Diimide

“…The addition of boric acid as a catalyst could improve the disassociation of hydrazine and reduce the diimide side reactions [ eqs 14 and 15 ]. 29 …”

“…This may be due to the boric acid accelerating the diimide formation and activating the reaction of gel formation. The addition of boric acid as a catalyst could improve the disassociation of hydrazine and reduce the diimide side reactions [eqs and ] …”

Penghidrogenan Getah Asli Cecair Menggunakan Sistem Mangkin Selenium

“…Model regresi dengan nilai R 2 di atas 0.9 dianggap sebagai model yang mempunyai korelasi yang tinggi (Li et al 2015). Selain itu, Hamzaoui et al (2008) (Kongsinlark et al 2012). Oleh itu, dapat disimpulkan bahawa suhu memainkan peranan yang penting di dalam penghidrogenan LNR.…”