聚氨酯胶黏剂/pu胶的分类之按照反应固化的组分进行分类

（1）多异氰酸酯胶黏剂（单体胶黏剂）　多异氰酸酯胶黏剂的毒性大，韧性较差，故很少以单体形式使用。一般将其与橡胶混合制备制得改性多异氰酸酯胶黏剂，或混入聚乙烯醇溶液制得乙烯类聚氨酯胶黏剂，该胶黏剂也可作为交联剂加入其他基料中使用。常用的多异氰酸酯胶黏剂有多苯基多异氰酸酯、二苯基二甲烷二异氰酸酯等。

（2）含异氰酸酯基聚氨酯胶黏剂　含有异氰酸酯基聚氨酯胶黏剂主要是含有—NCO的聚氨酯预聚物，它是由多异氰酸酯与多羟基化合物（聚酯或聚醚）的反应生成物。该预聚物具有较高的极性和较高的活性，能与含有活泼氢的物质反应，因此也具有较高的黏附性。该类胶黏剂又可分单组分、双组分、溶剂型、无溶剂型等类型。

（3）含羟基聚氨酯胶黏剂　含羟基聚氨酯胶黏剂是指含羟基的线型聚氨酯聚合物，由二异氰酸酯与二官能度的聚酯或聚醚反应生成。该胶黏剂可作为热塑性胶黏剂也可作为热固性胶黏剂，其中作为热塑性胶黏剂时，胶层柔软、易弯曲、耐冲击，具有较好的初黏性，但粘接强度较差、耐溶剂性能差、易蠕变；作为热固性胶黏剂时，主要是通过分子两端的羟基化学反应固化，该胶黏剂改善了上述的缺点，但柔软性和耐冲击性受到了影响。该胶黏剂属于双组分胶黏剂，使用前现场配置。

（4）聚氨酯树脂胶黏剂　聚氨酯树脂胶黏剂主要是由多异氰酸酯与多羟基化合物充分反应，制得的溶液、乳液、压敏胶以及粉末等不同品种的胶黏剂。把含异氰酸酯基聚氨酯胶黏剂中的异氰酸酯基进行封闭处理，制得的封闭性聚氨酯胶黏剂亦属于此类型。

(1) Polyisocyanate adhesive (monomer adhesive) polyisocyanate adhesive is seldom used in the form of monomer because of its high toxicity and poor toughness. In general, the modified polyisocyanate adhesive is prepared by mixing it with rubber, or the vinyl polyurethane adhesive is prepared by mixing it with polyvinyl alcohol solution. The adhesive can also be used as a cross-linking agent in other base materials. Commonly used polyisocyanate adhesives are polyphenyl polyisocyanate, diphenyl dimethyl diisocyanate, etc.

(2) Isocyanate based polyurethane adhesive isocyanate based polyurethane adhesive is mainly a polyurethane prepolymer containing - NCO, which is produced by the reaction of polyisocyanate and polyhydroxy compound (polyester or polyether). The prepolymer has high polarity and activity, and can react with substances containing active hydrogen, so it also has high adhesion. This kind of adhesive can be divided into single component, two-component, solvent-free and other types.

(3) Hydroxyl containing polyurethane adhesive hydroxyl containing polyurethane adhesive is a kind of linear polyurethane polymer containing hydroxyl, which is formed by the reaction of diisocyanate with polyester or polyether with difunctionality. The adhesive can be used as thermoplastic adhesive or thermosetting adhesive. When it is used as thermoplastic adhesive, the adhesive layer is soft, flexible, impact resistant and has good initial adhesion, but the adhesive strength is poor, the solvent resistance is poor and it is easy to creep; As a thermosetting adhesive, it is mainly cured by hydroxyl chemical reaction at both ends of the molecule. The adhesive improves the above shortcomings, but the softness and impact resistance are affected. The adhesive belongs to two-component adhesive, which is prepared on site before use.

(4) polyurethane resin adhesive polyurethane resin adhesive is mainly composed of polyisocyanates and polyhydroxyl compounds, which are produced by different kinds of adhesives such as solution, emulsion, pressure sensitive adhesive and powder. The isocyanate group in polyurethane adhesive containing isocyanate group is blocked, and the blocked polyurethane adhesive prepared also belongs to this type