聚酰胺6-聚氨酯嵌段共聚物的制备及其性能研究

Study on Preparation and Mechanical Properties of Polyamide 6-polyurethane Block Copolymers

为了改善浇铸聚酰胺6(MC-PA6)的冲击韧性,制备了聚酰胺6-聚氨酯(PA6-PU)嵌段共聚物。采用示差扫描量热分析(DSC)、动态力学性能分析(DMTA)以及静态力学性能测试研究了PU柔性组分对PA6-PU嵌段共聚物结构和性能的影响。结果表明,当PU柔性组分含量为15%～20%(质量分数,下同)时,共聚物中出现了2个熔融峰,表明晶粒尺寸分布较宽;DMTA确定PA6-PU嵌段共聚物只有1个玻璃化温度(α松弛峰),说明共聚物为单相体系。PA6-PU嵌段共聚物的力学性能数据表明,随PU组分含量的增加,共聚物的拉伸强度下降,但-50℃和25℃时的冲击强度大幅度提高。

In order to improve impact toughness of monomer casting polyamide 6, polyamide 6-polyurethane （PA6-PU） block copolymers are prepared by monomer casting process. Differential scanning calorimetry（DSC）, dynamic mechanical analysis（DMTA） and mechanical properties test are conducted to study influence of the content of PU soft component upon structure and properties of PA 6-PU block copolymers. The results show that there are two melting peaks at 15%-20% content of PU propolymer, which suggests the size distribution of crystal nucleus is wide. Single glass temperature of the copolymers is confirmed by DMTA illuminated the presence of a single phase in copolymers. The results of mechanical properties of the copolymers show that with the increases of PU content tensile strength of the copolymers decreases, the impact strength of the eopolymers can be significantly improved at -50℃ and 25℃.