The present disclosure belongs to the technical field of polymer materials, and in particular relates to a chain extender and a preparation method and application thereof, a recyclable thermosetting polyurethane and a preparation method thereof. The present disclosure provides a chain extender whose chemical formula is shown in formula I. The chain extender provided by the present disclosure contains two types of dynamic covalent bonds, and the total number of dynamic covalent bonds is 4. The thermosetting polyurethane prepared by the provided chain extender has better hot-pressing repair efficiency. The results of the examples show that under the same hot-pressing conditions, the repair efficiency of the thermosetting polyurethane prepared by the 4,4′-dithiodianiline chain extender is 59%. The repair efficiency of thermosetting polyurethane is 97%, which is significantly improved.

The present disclosure belongs to the technical field of polymer materials, and in particular relates to a chain extender and a preparation method and application thereof, a recyclable thermosetting polyurethane and a preparation method thereof. The present disclosure provides a chain extender whose chemical formula is shown in formula I. The chain extender provided by the present disclosure contains two types of dynamic covalent bonds, and the total number of dynamic covalent bonds is 4. The thermosetting polyurethane prepared by the provided chain extender has better hot-pressing repair efficiency. The results of the examples show that under the same hot-pressing conditions, the repair efficiency of the thermosetting polyurethane prepared by the 4,4′-dithiodianiline chain extender is 59%. The repair efficiency of thermosetting polyurethane is 97%, which is significantly improved.

Aqueous dispersion comprising polyurethane or polyurethane-urea, a preparation method therefor and a use thereof. The polyurethane or polyurethane-urea is prepared by reacting raw materials comprising the following components: a compound having a tertiary amine group and at least one NCO reactive functional group, a polyester polyol having a number average molecular weight of 400 to 5000 and a functionality of 2 to 3, an organic compound having at least two isocyanate groups, a hydrophilic compound having one or more of an ionic group, a potential ionic group and a non-ionic group and having 2 to 3 NCO reactive functional groups, and a mono-functional non-ionic hydrophilic compound having at least one NCO reactive functional group. The aqueous dispersion can be stably stored for a prolonged period of time, and an adhesive prepared from the aqueous dispersion has an improved hydrolysis resistance while maintaining good bonding strength and heat resistance.

Aqueous dispersion comprising polyurethane or polyurethane-urea, a preparation method therefor and a use thereof. The polyurethane or polyurethane-urea is prepared by reacting raw materials comprising the following components: a compound having a tertiary amine group and at least one NCO reactive functional group, a polyester polyol having a number average molecular weight of 400 to 5000 and a functionality of 2 to 3, an organic compound having at least two isocyanate groups, a hydrophilic compound having one or more of an ionic group, a potential ionic group and a non-ionic group and having 2 to 3 NCO reactive functional groups, and a mono-functional non-ionic hydrophilic compound having at least one NCO reactive functional group. The aqueous dispersion can be stably stored for a prolonged period of time, and an adhesive prepared from the aqueous dispersion has an improved hydrolysis resistance while maintaining good bonding strength and heat resistance.

The present invention provides a synthetic leather including at least a base (i), an adhesive layer (ii), and a skin layer (iii). The adhesive layer (ii) is formed of a urethane resin composition including a urethane resin (A) produced using an aromatic polyisocyanate (a1) as a raw material and water (B). The skin layer (iii) is formed of a urethane resin composition including an anionic urethane resin (X) having an anionic group concentration of 0.15 mmol/g or less and water (Y). The aromatic polyisocyanate (a1) preferably includes toluene diisocyanate. The urethane resin (A) has an aromatic ring concentration of 0.1 to 2.5 mol/kg.

The present invention provides a synthetic leather including at least a base (i), an adhesive layer (ii), and a skin layer (iii). The adhesive layer (ii) is formed of a urethane resin composition including a urethane resin (A) produced using an aromatic polyisocyanate (a1) as a raw material and water (B). The skin layer (iii) is formed of a urethane resin composition including an anionic urethane resin (X) having an anionic group concentration of 0.15 mmol/g or less and water (Y). The aromatic polyisocyanate (a1) preferably includes toluene diisocyanate. The urethane resin (A) has an aromatic ring concentration of 0.1 to 2.5 mol/kg.

Provided is a material having an excellent sound-absorbing performance which can be easily applied to the desired area at the operation site and which can effectively prevent sound leakage. The material includes an open-cell soft polyurethane foam prepared from a 2-part reactive urethane resin composition prepared from a polyisocyanate component and a polyol-containing component, wherein the polyol-containing component comprises a polyol component, catalysts, a foam stabilizer, an amine compound having primary or secondary amino groups, and carbon dioxide; wherein an average sound absorption coefficient of said polyurethane foam is 30% or more, measured in accordance with JIS A 1405-2:2007 for 63 hertz to 5000 hertz; and the length of liquid-dripping is within 300 mm.

The present invention relates to an acid-resistant and alkali-resistant composition, a preparation process thereof and use thereof in producing an article, and an article comprising a substrate coated or impregnated with the same and the preparation method and use of the article. The composition contains: at least one aqueous polyurethane dispersion having a carboxyl group; at least one crosslinking agent having an isocyanate reactive group; at least one crosslinking agent having a carboxyl reactive group; and optionally an additive; wherein, the amount of the carboxyl groups in said aqueous polyurethane dispersion is more than 0.05 wt %, based on the amount of said aqueous polyurethane dispersion being 100 wt %; the amount of said crosslinking agent having an isocyanate reactive group is 0.2 wt %-10 wt %, based on the amount of said composition being 100 wt %; the molar ratio of the carboxyl reactive groups to the carboxyl groups of said composition is more than 0.5. The film formed with the composition of the present invention has good acid-resistance and alkali-resistance. The product obtained by treating with the composition of the present invention has flat appearance and good handfed.

The present invention relates to an acid-resistant and alkali-resistant composition, a preparation process thereof and use thereof in producing an article, and an article comprising a substrate coated or impregnated with the same and the preparation method and use of the article. The composition contains: at least one aqueous polyurethane dispersion having a carboxyl group; at least one crosslinking agent having an isocyanate reactive group; at least one crosslinking agent having a carboxyl reactive group; and optionally an additive; wherein, the amount of the carboxyl groups in said aqueous polyurethane dispersion is more than 0.05 wt %, based on the amount of said aqueous polyurethane dispersion being 100 wt %; the amount of said crosslinking agent having an isocyanate reactive group is 0.2 wt %-10 wt %, based on the amount of said composition being 100 wt %; the molar ratio of the carboxyl reactive groups to the carboxyl groups of said composition is more than 0.5. The film formed with the composition of the present invention has good acid-resistance and alkali-resistance. The product obtained by treating with the composition of the present invention has flat appearance and good handfed.

The present disclosure sets forth ink compositions having a biodegradable polyurethane binder that can be used for textile printing. In one example, an ink composition can include water, an organic co-solvent, a colorant, and a biodegradable polyurethane binder. The biodegradable polyurethane binder can include prepolymer segments including polymerized monomers of a diisocyanate and a diol. The diol can include to terminal 6-hydroxyhexanoate groups linked by an organic linking group. Chain extenders can connect the prepolymer segments. The chain extenders can include a polymerized diamine.