Methods of making sequence-defined polymers and sequence-defined polymers. The methods are based on the orthogonal reactivity of monomers having at least two different functional groups. The sequence-defined polymers can be used in various applications. For example, the SDPs (e.g., pH sensitive SDPs) are used in cell lysis methods or as molecular vehicles to transport drug cargo into cells.

Chemically resistant sealant compositions include high equivalent weight sulfur-containing prepolymers. Upon exposure to chemicals the properties of sealants prepared using the prepolymers exhibit excellent fuel and phosphate ester resistance.

A method for preparing a compound and a method for preparing a polymer employing the same are provided. The method for preparing a compound includes reacting a compound having a structure represented by Formula (I) with a compound having a structure represented by Formula (III) in the presence of a compound having a structure represented by Formula (II) to obtain a compound having a structure represented by Formula (IV) ##STR00001##
wherein Ar.sup.1 is substituted or unsubstituted aryl group; X is O, S, or NH; R.sup.1 is independently hydrogen or C.sub.1-6 alkyl group; R.sup.2 is hydroxyl group, C.sub.1-6 alkyl group, phenyl group, or tolyl group; and R.sup.3 is independently C.sub.1-6 alkyl group, C.sub.5-8 cycloalkyl group, or C.sub.2-6 alkoxyalkyl group.

A method for preparing a compound and a method for preparing a polymer employing the same are provided. The method for preparing a compound includes reacting a compound having a structure represented by Formula (I) with a compound having a structure represented by Formula (III) in the presence of a compound having a structure represented by Formula (II) to obtain a compound having a structure represented by Formula (IV) ##STR00001##
wherein Ar.sup.1 is substituted or unsubstituted aryl group; X is O, S, or NH; R.sup.1 is independently hydrogen or C.sub.1-6 alkyl group; R.sup.2 is hydroxyl group, C.sub.1-6 alkyl group, phenyl group, or tolyl group; and R.sup.3 is independently C.sub.1-6 alkyl group, C.sub.5-8 cycloalkyl group, or C.sub.2-6 alkoxyalkyl group.

Polythioaminal polymers are made from hexahydrotriazine precursors and dithiol precursors. The precursors are blended together and subjected to mild heating to make the polymers. The polymers have the general structure ##STR00001##
wherein each R.sup.1 is independently an organic or hetero-organic group, each R.sup.2 is independently a substituent having molecular weight no more than about 120 Daltons, X and Z are each a sulfur-bonded species, at least one of X and Z is not hydrogen, and n is an integer greater than or equal to 1. X and Z may be hydrogen or a functional group, such as a thiol-reactive group. The reactive thiol groups of the polythioaminal may be used to attach thiol-reactive end capping species. By using water soluble or water degradable dithiols, such as polyether dithiols, water soluble polythioaminals may be made. Some such polymers may be used to deliver therapeutics with non-toxic aqueous degradation products.

Polythioaminal polymers are made from hexahydrotriazine precursors and dithiol precursors. The precursors are blended together and subjected to mild heating to make the polymers. The polymers have the general structure ##STR00001##
wherein each R.sup.1 is independently an organic or hetero-organic group, each R.sup.2 is independently a substituent having molecular weight no more than about 120 Daltons, X and Z are each a sulfur-bonded species, at least one of X and Z is not hydrogen, and n is an integer greater than or equal to 1. X and Z may be hydrogen or a functional group, such as a thiol-reactive group. The reactive thiol groups of the polythioaminal may be used to attach thiol-reactive end capping species. By using water soluble or water degradable dithiols, such as polyether dithiols, water soluble polythioaminals may be made. Some such polymers may be used to deliver therapeutics with non-toxic aqueous degradation products.

Compositions that are curable to polythioether polymers are provided, comprising: a) a dithiol monomer; b) a diene monomer; c) a radical cleaved photoinitiator; d) a peroxide; and e) an amine; where the peroxide and amine together are a peroxide-amine redox initiator. In some embodiments, the amine is a tertiary amine. In some embodiments, the amine is selected from the group consisting of dihydroxyethyl-p-toluidine, N,N-diisopropylethylamine, and N, N, N, N, N-pentamethyl-diethylenetriamine. In some embodiments, the peroxide is selected from the group consisting of di-tert-butyl peroxide, methyl ethyl ketone peroxide, and benzoyl peroxide. In some embodiments, the composition may additionally comprise a polythiol monomer having three or more thiol groups.

Compositions that are curable to polythioether polymers are provided, comprising: a) a dithiol monomer; b) a diene monomer; c) a radical cleaved photoinitiator; d) a peroxide; and e) an amine; where the peroxide and amine together are a peroxide-amine redox initiator. In some embodiments, the amine is a tertiary amine. In some embodiments, the amine is selected from the group consisting of dihydroxyethyl-p-toluidine, N,N-diisopropylethylamine, and N, N, N, N, N-pentamethyl-diethylenetriamine. In some embodiments, the peroxide is selected from the group consisting of di-tert-butyl peroxide, methyl ethyl ketone peroxide, and benzoyl peroxide. In some embodiments, the composition may additionally comprise a polythiol monomer having three or more thiol groups.

Compositions that are curable by free radical redox reactions are disclosed. Free radical curing reactions between polythiols and polyalkyenyls are initiated by the reaction of metal complexes and organic peroxides. The compositions are useful as sealants.

Compositions that are curable by free radical redox reactions are disclosed. Free radical curing reactions between polythiols and polyalkyenyls are initiated by the reaction of metal complexes and organic peroxides. The compositions are useful as sealants.