阻燃型无甲醛双组分水性聚氨酯木材胶黏剂的研究

聚乙烯醇(PVA)通过KMnO4氧化为氧化聚乙烯醇(O-PVA),然后与亚磷酸二乙酯发生加成反应生成含磷聚乙烯醇(P-PVA),通过红外光谱和核磁共振确定了其结构。将P-PVA作为双组分水性聚氨酯主剂,多亚甲基多苯基异氰酸酯(PAPI)作为固化剂,考察了所制备的胶黏剂在木材刨花板中的阻燃性能。当施胶量为18%时,刨花板的极限氧指数(LOI)为27.9。热重分析表明,添加了以P-PVA为主剂的聚氨酯胶(P-PU)后,与普通聚氨酯胶(PU)相比,木材刨花板初始分解温度提前,延长了低温脱水炭化阶段,同时提高了在高温下的残炭量。

Study on Flame-retarding Formaldehyde-free Two-component Waterborne-polyurethane Wood Adhesive

Phosphited polyvinyl alcohol(P-PVA)was synthesized from diethyl phosphite and oxidated polyvinyl alcohol(O-PVA)which was obtained by oxidation of polyvinyl alcohol with KMnO4.The structure of P-PVA was confirmed by FT-IR and 1H NMR.Using P-PVA as the main component and polyaryl polymethylene isocyanate(PAPI)as curing agent,the flame-retarding properties of the prepared particle board were investigated to have a limiting oxygen index(LOI)of 27.9,when the loading of P-PU was 18 %.Result of TGA showed that compared with normal polyurethane(PU)adhesive,P-PU adhesive can decrease the initial decomposition temperature which prolongs the stage of low-temperature dehydration-carbonization and increases the yield of residue char of wood particleboard at high temperature.