The synthesis of a new class of high-barrier polymers, poly(hydroxy amide ethers), is described. The polymers are formed by the reactions of bisphenol-A diglycidyl ether, OCH2CHCH2OC6H4C(CH3)2C6H4OCH2CHCH2O, and amide-containing bisphenols of the general formula HOC6H4NHC(O)RC(O)NHC6H4OH [R = −(CH2) n −, −CH2C6H4CH2−, or −C6H4−] or HOC6H4NHC(O)C6H4OH at 140−160 °C in propylene glycol monophenyl ether solvent using ethyltriphenylphosphonium acetate as initiator. High-molecular-weight poly(hydroxy amide ethers) of the general structure [−CH2CH(OH)CH2OC6H4C(CH3)2C6H4OCH2CH(OH)CH2OC6H4NHC(O)RC(O)NHC6H4O−] n or [−CH2CH(OH)CH2OC6H4C(CH3)2C6H4OCH2CH(OH)CH2OC6H4NHC(O)C6H4O−] n are readily prepared. The amorphous thermoplastics have glass transition temperatures (T g) of 90−133 °C and oxygen transmission rates (O2TR) which range from 0.7 to 4.6 cc·mil/100 in.2·atm·day (barrier units or BU) at 23 °C and 47−85% relative humidity. The effect that polymer structure has on oxygen barrier properties and T g is described. The characterization, structure determination, and properties of the poly(hydroxy amide ethers), as well as the amide-containing bisphenol precursors, are also presented.

No abstract

SynopsisMichael additions of the secondary diamines N,W-dimethyl-l,6-hexanediamine (14) or piperazine to the electrophilic carbon-carbon double bonds of N,N'-bismaleimido-4,4'-diphenylmethane (2) or N , N -bismaleimido-l,8-octane (4) afford four unusual, high-molecular-weight (qinh = 0.49-2.16 dL/g) polyimides (10-13). The most interesting of these, polymer 12 (the product of 4 and 14), is a tough elastomeric resin with a glass transition temperature (T,) near 0°C; in contrast, 10,11, and 13 exhibit Tg > 86°C. Freshly prepared 12 is soluble and thermoplastic (12 is readily compression molded a t llO"C), but the bulk polymer crosslinks slowly under ambient laboratory conditions and eventually (48 days) becomes insoluble, while 10, 11, and 13 remain soluble indefinitely. Along with further comparisons of the properties of 10-13, details of the synthesis and characterization of these new polyimides are described. Also discussed are reactions of bismaleimide 2 with 1,6-diaminohexane, which unlike the formation of linear 10-13, generate crosslinked, insoluble products.

Dithiols and diamines react with bismaleimides via a Michael type process to afford high-molecular-weight poly(imido sulfides) and poly(aspartimides), properties of which range from those of rubberlike elastomers to those of high-melting thermoplastics. This review presents a brief summary of the requirements for synthesis of these polymeric Michael adducts along with a discussion of structural effects on the thermal, morphological, and mechanical characteristics of the materials. Copolymeric poly(imido sulfides) as well as polymers from bis(dichloromaleimides) and bisphenols also are described.

No abstract

The synthesis of a series of new high-barrier poly(hydroxy amide ethers) is described. The polymers are formed by the reactions of Bisphenol A diglycidyl with a series of N,N‘-alkylenebis(4-hydroxybenzamides) of general formula HOC6H4CONHRNHCOC6H4OH [R = −(CH2)2 - 6−, −CH2CH(OH)CH2−, −CH2C6H4CH2−, or −C6H4−] at 140−160 °C in propylene glycol monophenyl ether solvent using ethyltriphenylphosphonium acetate as initiator. Poly(hydroxy amide ethers) of general structure [−CH2CH(OH)CH2OC6H4C(CH3)2C6H4OCH2CH(OH)CH2OC6H4CONHRNHCOC6H4O−] n are readily prepared in high molecular weight. These amorphous thermoplastics have glass transition temperatures (T g) of 110−152 °C and oxygen transmission rates (O2TR) which range from 1.0 to 2.8 cc·mil/(100 in.·atm·day) (barrier units or BU) at 23 °C and 58−86% relative humidity. The effect that polymer structure has on O2TR and T g is discussed. Of special interest is the poly(hydroxy amide ether) in which R = m-C6H4−. This polymer combines a good oxygen barrier (1.5 BU) with the T g of an engineering thermoplastic (152 °C).

Various alkanedithiols [HSRSH; R = (CH2)3–6 orCH2CH2OCH2CH2] add to the carbon‐carbon double bonds of N,N′‐bismaleimido‐1,8‐octane (1) at room temperature in m‐cresol that contains triethylamine as a catalyst to produce the corresponding polyimidosulfides (3) in yields of 75–86% and with inherent viscosities (ηinh) of 0.30–1.05 dL/g. In general (3) are amorphous, elastomeric materials that undergo glass transitions (Tg) within the range of 6.5–13°C but product (3a) [R = (CH2)6] is a tough, leatherlike polymer that exhibits Tg = 35°C and a melting transition at 77°C. X‐ray analysis indicates that (3a) is ca. 37% crystalline. In addition to further details of the synthesis and properties of polyimidosulfides (3), comparisons are made between crystalline (3a) and a structurally analogous but morphologically dissimilar, elastomeric polyaspartimide synthesized earlier from (1) and N,N′‐dimethyl‐1,6‐hexanediamine.

New epoxy‐based thermoplastics for barrier packaging are discussed here (see Figure). The polymers, poly (hydroxyaminoethers), are typically generated through reactions of various dinucleophiles with epoxy monomers. The effects of functionalization, branching, and copolymerization on the mechanical, adhesive, and barrier properties of these resins are reviewed.