聚醚乙酰乙酸酯对可发性酚醛树脂的改性

以乙酰乙酸乙酯和聚醚二元醇为原料,浓硫酸为催化剂,制备了结构稳定且酮式与烯醇式结构共存的聚醚乙酰乙酸酯,通过红外光谱、核磁共振氢谱和碳谱对其结构进行了表征。结果表明,两种结构共存的聚醚乙酰乙酸酯已经成功合成。以聚醚乙酰乙酸酯与苯酚、多聚甲醛为原料,制备了一种新型聚醚酚醛树脂,通过红外光谱、核磁共振氢谱、固含量和游离甲醛含量对其进行测试和表征。结果表明,聚醚乙酰乙酸酯成功引入酚醛树脂的分子结构中,所合成的聚醚酚醛树脂固含量提高至91.2%,游离甲醛含量降低至0.012%。将合成的新型酚醛树脂与基础热固性酚醛树脂按照一定比例混合发泡,所制得的酚醛泡沫氧指数最高可达38.8%,冲击强度和压缩强度均有提高。

CPFE的表面和界面性质对破乳过程的影响

以腰果酚和甲醛为原料合成腰果酚醛树脂起始剂,再与环氧乙烷(EO)和环氧丙烷(PO)聚合,合成腰果酚醛树脂嵌段聚醚破乳剂(CPFE)。采用表面张力法测定了CPFE的临界胶束浓度(cmc)为80mg/L,对应的表面张力值(γcmc)为17.38mN/m。采用旋滴法测定了CPFE的油-水界面张力,考察了CPFE质量浓度和温度对油-水界面张力的影响。结果表明,随着CPFE质量浓度增加,油-水界面张力显著下降;随着温度升高,CPFE的界面活性下降,表明CPFE适合在低温环境下使用。采用单滴法测定了油滴破裂速率常数k随CPFE质量浓度的增加而增大。

Synthesis of Phenolic Resin Blended Castor Oil Based Modified Polyol for Two Component Polyurethane Coating

Castor oil is used to synthesize phenolic resin modified polyol. Castor oil, phenolic resin were taken in the molar ratio 0.07：0.027 and diethylene glycol （DEG） was also taken in varying hydroxyl numbers to achieve chemical modification in the backbone of synthesized polyol. Physico-chemical properties like acid value, OH value and moisture content of the modified polyol were measured. The prepared phenolic resin blended polyol were reacted with 4, 4-methylene diisocyanate and 2, 4-toluene diisocyanate to formulate the two component polyurethane （PU） coatings. Prepared coating is used to study properties such as gel time, surface dry, tack free and hard surface drying times. It was found that phenolic resin and diethyleneglycol used in synthesizing castor oil based modified polyols show the significant changes in physico-chemical properties of synthesized polyols. The variation in physico-chemical properties of synthesized polyol provide the information for desirable curing of polyurethane systems.