Mechanical properties and transition temperatures for copolymers of N‐n‐alkylacrylamides and acrylonitrile

Abstract

Random copolymers of N‐n‐butyl‐, N‐n‐octyl‐, or N‐n‐octadecylacrylamide with acrylonitrile were prepared in tert‐butanol at 60°C. to test the effect of amide homologs as internal plasticizers. At room temperature under high deformations all samples showed brittle failure; at 100°C. flexible and resilient copolymers were obtained. At low deformations, torsional stiffness values Tf followed the equations of Wood, Fox, and Dimarzio and Gibbs, the latter two modified by use of mole fraction instead of weight fraction. Mole fraction appeared to function better than weight fraction for these special cases where wi > 2mi and where modulus‐temperature curves were broad. Because literature values for the glass (or brittle) temperatures of homologs of poly‐n‐alkyl acrylates, methacrylates, n‐alkyl styrenes and alkenes, and estimated values for poly‐N‐n‐alkylacrylamides, plotted as a function of the logarithm of the number of single bonds in repeat units, extrapolate to an average value of −111°C. at a chain length of eighteen carbon atoms, and because side‐chain melting points of linear eighteen carbon side‐chain homologs appear to have a common value of 48–50°C. regardless of structure, it was concluded that similar glass and melting transitions are obtained when the side chain reaches eighteen carbon atoms in any series of homologs. Transitions for longer side‐chain lengths then approach the limit of a polyethylene graft, where Tg is −81°C. and Tm is 137°C.

Polymeric Pseudo-Liquid Membranes from Poly(N-oleylacrylamide)

“…Dibenzo-18-crown-6 (DB18C6), dibenzo-21-crown-7 (DB21C7), and O -allyl- N -(9-anthracenylmethyl)cinchonidinium bromide (AAMC) ( Figure 11 ) were obtained from Sigma-Aldrich (St. Louis, MO, USA) and used as received. N -oleylacrylamide (C18AAm) was prepared from acryloyl chloride and N -oleylamine [ 56 ]. 2,2′-Azobis(2-methylpropionitrile) (AIBN) [ 57 ] and toluene [ 58 ] were purchased from Nacalai Tesque, Inc. (Kyoto, Japan) and purified by conventional methods.…”

Photochemistry of .beta.-iodoacrylamides

“…The unsymmetrically substituted amine (i)-sedridine (13) was prepared by a modification of known procedures (see Experimental Section),11 and its cis-d-iodoacrylamide 14 photolyzed.12 A complex reaction mixture resulted (Scheme VI) which after extensive chromatography afforded the ring-cleaved ketones 15 (21%) and 16 (5%) and the enamide 17 (25%). 13 The structures of the ketones 15 and 16 were assigned on the basis of spectroscopic data [for 15 -CH2C(=0)CH2-CH(OCH3)CH3 ¡w (neat) 1705 crn'l, (CDC13) doublet (J = 6 Hz) 1.17 ppm (3 H), complex 2.33-2.77 (4 H), singlet 3.33 (3 H), and triplet of quartets (J = 6 and 6 Hz) 3.82 (1 H); CH2=CHC(=0)NHpmax (neat) 3260, 1655 (s), and 1625 cm-1 (s), (CDCls) doublet of doublets (J = 6 and 6 Hz) 5.60 ppm (1 H), two doublets (J = 6 and 6 Hz) both at 6.27 (1 H each); for 16 -CH2C(=0)CH=CHCH3 i-max (KBr) 1690 cm-1, (CDC13) doublet of doublets (J = 6 and 2 Hz) 1.90 ppm (3 H), broad triplet 2.60 (2 H), doublet of CHC13, aq HC1 J quartets (J = 6 and 16 Hz) 6.85 (1 H); CH2= CHC(-0)NHymax (KBr) 3230, 1650 (s), and 1625 (s) cm""1, (CDCla) doublet of doublets (J = 8 and 4 Hz) 5.57 ppm (1 H), complex 5.90-6.50 (4 H) includes the a proton of the ,/3-unsaturated ketone moiety, m/e 195 (M+)] as well as the conversion of 15 to 16 upon treatment with aqueous acid (Scheme VI). The assignment of structure to the enamide 17 presented a greater problem, since this material was inert to acidic hydrolysis conditions that would normally be expected to cleave an enamide linkage.…”

“…This hydroxyl group would be expected to be labilized by the formation of enamide 29, and should undergo a facile exchange with methanol in the presence of HI. The dehydration of 29 might account for the formation of 16, although 16 might also arise following ring cleavage to 15 through the loss of methanol. o>] \°""TO 16 15…”

Terpolymers. II. Mechanical properties and transition temperatures of terpolymers of vinyl stearate, vinyl acetate, and vinyl chloride

“…'~ Internal plasticizers derived from the higher fatty acids and alcohols, because of the lower glass transition temperatures of their homopolymers, l5. 16 are more efficient than those derived from lower homologs. Vinyl stearate and the vinyl esters of shorter-chain fatty acids have been used to modify the mechanical properties of poly(viny1 chloride),17 but only over a limited composition range.…”