Abstract9,10‐Bis(hydroxymethyl)triptycene, 9,10‐dihydro‐9,10‐bis(hydroxymethyl)‐9,10‐ethanoanthracene, 9,10‐dihydro‐9,10‐bis(hydroxymethyl)‐9,10‐(2,3‐bicyclo[2.2.1] heptano)‐anthracene, 9,10‐dihydro‐9,10‐bis(hydroxymethyl)‐N‐phenyl‐9,10‐ethanoanthracene‐11,12‐dicarboximide, and 9,10‐bis(carbethoxy)triptycene have been prepared and employed as modifying agents to improve the physical properties of polyesters such as poly(ethylene terephthalate). Especially noteworthy are the high glass transition temperatures (Tg) which can be obtained.
Ring‐substituted styrenes were prepared and polymerized. They usually had higher glass transition temperatures than polystyrene. In some disubstituted systems the Tg was an additive function of the individual groups. Crystallinities of methyl‐substituted polymers varied, depending upon the ring positions involved. Crazing tendencies were equivalent to those in polystyrene.
Series of α‐olefins were prepared and polymerized with Al(C2H5)3–VCl3 catalyst. Melting points, softening points, and degrees of crystallinity of the polymers were measured and the physical nature of the systems was discussed. Olefins studied were those having the general formula CH2CH(CH2)xR, where x = 0−3, and R is methyl, isopropyl, tert‐butyl, phenyl, or cyclohexyl.
Relative reactivity ratios have been determined for o‐chlorostyrene with five lower acrylates and methacrylates, respectively, and for methyl acrylate with a number of substituted styrenes in free‐radical copolymerization. Analysis of the data shows that: (a) acrylates are less reactive than methacrylates with o‐chlorostyrene; (b) length of the side chain has little or no effect in methacrylates, but its effect is pronounced in acrylates with respect to their reactivity ratios; (c) chlorine substitution in the side chain of either acrylates or methacrylates has a significant influence on the reactivity ratio; (d) relative reactivity ratio data for methyl acrylate with substituted styrenes fail to show the expected relationship between monomer structure and resonance theory, inductive effect and, consequently, the Hammett σ values.
Thermal properties and resistance to crazing of copolymers and terpolymers of 2,5‐dichlorostyrene and 3,4‐dichlorostyrene have been studied. Copolymers based on 2,5‐dichlorostyrene showed little or no improvement over polystyrene in craze resistance or glass transition temperature. Although copolymers of 3,4‐dichlorostyrene were generally brittle and crazed readily, poly(3,4‐dichlorostyrene‐co‐2‐ethylhexyl methacrylate) and poly(3,4‐dichlorostyrene‐co‐n‐hexyl methacrylate) crazed less readily than polystyrene.
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