The invention relates to a composition for preparing a flexible foam and its application. The composition comprises the following components: a. an isocyanate mixture; b. a polymer polyol mixture; c. an isocyanate-reactive group-containing compound having a number average molecular weight of 32-400 g/mol; d. an aqueous alkali metal salt and/or ammonium bicarbonate solution, having a concentration of greater than or equal to 1.5 wt % and less than 30 wt %, and a pH value of less than 9.5; and e. a metal catalyst; wherein the amount of the tertiary amine catalyst in the composition is not more than 0.1 wt %, and the isocyanate index of the composition is 70-120. The composition has a high reaction efficiency and can meet the quantitative production requirements of the textile industry. The flexible foam prepared from the composition has a good phenolic yellowing resistance, and can meet the comprehensive requirements of the textile industry for a high rebound resilience, a good gas permeability, a ultraviolet yellowing resistance and the like of the foam.

Provided is a compound having higher fluorescence quantum yield and higher optical stability than a conventional FLAP and a polymer compound containing the compound. ##STR00001## A: seven or eight-membered ring structure, Y.sup.1, Y.sup.2, Y.sup.3: halogen atom or the like, a1: number of Y.sup.1, a2: number of Y.sup.2, B: number of Y.sup.3, 0≤m and n≤3: when 1≤m≤3, Y.sup.1 may be substituted with a structure portion defined by m, when 1≤n≤3, Y.sup.2 may be substituted with a structure portion defined by n, and B.sup.1, B.sup.2: Formulas (2-1) to (2-3). ##STR00002## C.sup.1, C.sup.2, C.sup.3: structure containing a cyclic hydrocarbon compound, D.sup.1, D.sup.2, D.sup.3: substructure that inhibits aggregation, E.sup.1, E.sup.2, E.sup.3: polymerizable substructure, Z.sup.1: hydrogen atom or the like, c: number of substituent groups Z.sup.1, Z.sup.2, Z.sup.3: hydrogen atom or the like, and may form a ring with C.sup.2.

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.

A storage stable one component aqueous basecoat composition containing a melamine formaldehyde crosslinker and a resin having groups reactive to the melamine formaldehyde crosslinker under acid catalysis is provided. The basecoat composition is curable at a temperature of 110° C. or less when cured wet on wet with a solvent borne clear coat composition containing a polyisocyanate crosslinker. Also provided is a wet on wet two layer coating containing the one component aqueous basecoat and the solvent borne clear coat, a wet on wet three layer coating containing an aqueous primer, the one component aqueous basecoat and the solvent borne clear coat and a cured topcoat coating obtained by curing the wet on wet two layer coating.

A storage stable one component aqueous basecoat composition containing a melamine formaldehyde crosslinker and a resin having groups reactive to the melamine formaldehyde crosslinker under acid catalysis is provided. The basecoat composition is curable at a temperature of 110° C. or less when cured wet on wet with a solvent borne clear coat composition containing a polyisocyanate crosslinker. Also provided is a wet on wet two layer coating containing the one component aqueous basecoat and the solvent borne clear coat, a wet on wet three layer coating containing an aqueous primer, the one component aqueous basecoat and the solvent borne clear coat and a cured topcoat coating obtained by curing the wet on wet two layer coating.

New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling Chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

Composites having a polymer or natural leather skin layer and a polyurethane foam layer are made in a molding process. The polyurethane foam layer is made from a foam formulation that includes certain polyester polyols. The presence of the polyester polyol improves flow characteristics of the foam formulation. The foam so produced has unexpectedly low quantities of VOCs.

Polyurethane foams are made by curing a reaction mixture that contains an aromatic polyisocyanate, at least one isocyanate-reactive material having an average functionality of at least 2 and an equivalent weight of at least 200 per isocyanate-reactive group, at least one blowing agent, at least one surfactant and at least one catalyst, at least one cyclic 1,3-diketone compound, at least one aminoalcohol or alkylhydroxylamine and an alkali metal, phosphonium or ammonium sulfite. Foams so produced emit low levels of formaldehyde, acetaldehyde, acrolein and propionaldehyde.