二胺结构对聚亚胺vitrimer材料性能的影响

Effects of Diamine Structure on Properties of Polyimine Vitrimer Materials

利用对苯二甲醛和三(2-氨基乙基)胺分别与己二胺、1,4-二氨基环己烷、对苯二胺和间苯二胺发生席夫碱反应制备了PTI–H,PTI–CH,PTI–pP和PTI–mP四种聚亚胺vitrimer材料,并通过傅里叶变换红外光谱对其结构进行了表征。通过拉伸测试和动态热机械分析测试研究了二胺结构对聚亚胺vitrimer材料物理力学性能的影响。结果表明,具有刚性结构、较高交联密度的PTI–CH和PTI–mP展现出高的拉伸强度(≥55 MPa)、储能模量(>1.8 GPa)和低断裂伸长率(≤36%);具有刚性苯环结构但交联密度较低的PTI–pP具有最高的断裂伸长率(55.9%)和低的拉伸强度(38 MPa)、储能模量(1.77 GPa);具有柔性脂肪链结构、较低交联密度的PTI–H显示最低的拉伸强度(30.9 MPa)、储能模量(1.68 GPa)和较高的断裂伸长率(51.2%)。四种聚亚胺材料在玻璃化转变温度方面的排序为PTI–CH(86℃)>PTI–mP(84℃)>PTI–H(67℃)>PTI–pP(63.8℃)。四种聚亚胺材料在较低温度(120℃)下可重塑,经过两次重塑后,PTI–H的拉伸强度无明显降低,PTI–CH,PTI–pP和PTI–mP的拉伸强度有所提高,但四种材料的断裂伸长率均下降。

Four kinds of polyimine vitrimer materials (PTI–H,PTI–CH,PTI–pP and PTI–mP) were prepared by the schiff base reaction of p-phthalaldehyde and tris(2-aminoethyl)amine with 1,6-hexamethylenediamine,1,4-cyclohexanediamine,p-phenylenediamine and m-phenylenediamine respectively.The material structures were characterized by Fourier transform infrared spectroscopy.The effects of the diamine structure on the physical and mechanical properties of polyimine vitrimer materials were studied by tensile test and dynamic mechanical analysis.The results show that polyimine vitrimer materials (PTI–CH and PTI–mP) with rigid structure and high crosslinking density exhibit high tensile strength (≥55 MPa),storage modulus (>1.8 GPa) and low elongation at break (≤36%).And PTI–pP with rigid benzene ring structure but low crosslinking density has highest elongation at break (55.9%),low tensile strength (38 MPa) and storage modulus (1.77 GPa).However,PTI–H with flexible fatty chain structure and low crosslinking density shows lowest tensile strength (30.9 MPa),storage modulus (1.68 GPa) and better elongation at break (51.2%).The sequencing of glass transition temperature of the four materials is PTI–CH(86℃)>PTI–mP(84℃)>PTI–H(67℃)>PTI–pP(63.8℃).All four kinds of polyimine vitrimer materials can be remolded at a lower temperature (120℃).After twice remodeling,the tensile strength of PTI–H does not decrease significantly,while the tensile strength of PTI–CH,PTI–pP and PTI–mP increase,but the elongation at break all decrease.