Copolymerization of nadic anhydride with styrene: Reactivity ratios

Abstract

The free radical copolymerization of nadic anhydride (NA) and styrene (St) at 80°C has been investigated for the first time. The copolymerization was done in toluene using benzoyl peroxide as initiator. The monomer reactivity ratios were calculated from the copolymer composition (estimated from the acid value) by using Fineman–Ross, Kelen–Tüdös, and Extended Kelen–Tüdös methods. The reactivity ratios (rNA, = 0.34, rST = 0.84) implied a good copolymerizability for the monomer pair and existence of an azeotropic composition at fNA = 0.195. The unsaturation in nadic anhydride exhibited good copolymerizability despite the fact that the double bond is isolated and allylic in nature. The usual retardation by the allylic protons was not significantly felt in this case, as the allylic protons were located at a bridge head posing geometric restrictions for stabilization of the allylic free radicals. However, an increase in concentration of NA in the feed decreased the overall rate of copolymerization. Based on the reactivity ratio, the probability for formation of sequences of NA in its copolymer with styrene was computed for a few compositions.

3-Methacryloxypropyltrimethoxysilane-Modified Hydroxyl Acrylate Pressure-Sensitive Adhesive with High Antiplasticity for Efficient Transdermal Drug Delivery

“…Based on previous studies, the reactivity ratios were estimated using Fineman–Ross, Inverted Fineman–Ross, and Kelen–Tüdös methods. − The mole fraction in the feed ( f ) and the mole fraction in the copolymer determined by 1 H NMR ( F ) are shown in Table S6 (Supporting Information). The results showed that the r 1 × r 2 , r 1 × r 3 , and r 1 × r 4 of AAOK were close to 1, and the r 1 , r 2 , r 3 , and r 4 were all <1 (Table S7, Supporting Information).…”

“…The copolymer reactivity ratio of KH-570 with each monomer was estimated by the Fineman–Ross, inverted Fineman–Ross, and Kelen–Tüdös methods. − A series of copolymers were synthesized as the ratios of AAOK-1, AAOK-2, AAOK-3, and AAOK-4, and the reaction time of the copolymer were controlled at 10 min to maintain low conversations (<30%). The mole fraction of KH-570 in the copolymers was determined from the integration ratios of the corresponding peaks as determined by 1 H NMR.…”

On the toughening of unsaturated polyester resins using nadimide end‐functionalized polyether telechelics

“…Hence, in this case, it was separately determined for the nadic anhydride-styrene pair (Table 3). [27] The reactivity ratio implies that nadic groups have only a moderate propensity for copolymerization. Homo or co-polymerization of these groups normally proceeds with great difficulty due to the isolated nature of the double bond and the presence of allylic proton that led to degenerative transfer.…”

“…The reactivity ratios of nadic with styrene (r n = 0.34, r s = 0.84) predict reasonably good proportion of adjacent sequence of polyether. [27] This may not be conducive for a tough system as this creates an environment for crystallization of the polyether segments. Too much crystallinity of polyether can result in a brittle matrix.…”

“…We also calculated the reactivity ratio of copolymerization of nadic anhydride and styrene and it was found to be r 1 = 0.34 and r 2 = 0.84 by extended Kelen-Tudos method. [27]…”