【作者】 陈玉洁；

【导师】 吴唯；

【作者基本信息】 华东理工大学 ， 材料科学与工程， 2012， 博士

【摘要】 本论文以氢键联接小分子或低聚物自组装形成物理网状结构超分子弹性体聚合物概念为基础,设计与合成了新型热回复性多元氢键超分子聚合物。采用简便的一锅法反应成功制备了一系列由酰胺低聚物及其封端产物分子链间通过多元氢键联接自组装形成的氢键超分子聚合物,对其分子结构、分子量及其分布、机械性能、结晶与熔融、热稳定性、热回复与加工性能、类橡胶弹性、动态流变性能等进行了详细表征。本论文提出了多元氢键超分子聚合物的相转变模型,并对其分子链动力学、氢键热动力学和自组装机理进行了深入探讨。分别通过二聚脂肪酸(DFA)和乙二胺(EAH)的酰胺缩聚反应和对甲苯磺酰异氰酸酯(PTSI)的封端反应,并改变二聚脂肪酸种类(BX-1和BX-4)和异氰酸酯含量,成功制备了一系列不同配方的酰胺低聚物BX-1-EAH和PTSI封端的酰胺低聚物BX-1-EAH-PTSI和BX-4-EAH-PTSI,产物在冷却过程中,低聚物分子链之间通过多元氢键联接自组装形成物理网状结构的氢键超分子聚合物。由1H-NMR和FT-IR分析证实,在氢键超分子聚合物的制备中成功发生了酰胺化反应和异氰酸酯的封端反应,且最终形成的氢键超分子聚集体中存在大量分子链上酰胺基团、磺酰脲基团间形成的C=O……NH、S=O……NH多元氢键,表明超分子聚合物具备氢键物理网状结构。GPC和ESI-TOF-MS测试表明,酰胺低聚物的分子量较低,且具有较宽的分子量分布,推断三种低聚物的聚合度低于10。氢键超分子聚合物具有优良的机械性能,拉伸强度最高达13.2MPa,球压痕硬度最高为20.3N/mm2。当乙二胺与二聚酸的摩尔比为1.2：1时,氢键超分子聚合物得到最高的拉伸强度和断裂伸长率。以BX-4为原料的氢键超分子聚合物不溶凝胶含量为3.2%,产生更多的支化交联微区,拥有更高的拉伸强度、模量和硬度。氢键超分子聚合物具有氢键物理交联网络与化学交联微区并存的结构形式,DMA结果表明氢键超分子聚合物在低温下(<-30℃)处于玻璃态,呈现出硬塑料的性质；在10℃左右发生了玻璃化转变过程,产物在Tg和室温之间呈现出高弹态,在室温时体现为橡胶弹性性质。氢键超分子聚合物熔点低,样品熔点范围在88-100℃；结晶度小,熔融焓(ΔHm)值范围在8.5-12.5J/g；热稳定性好,热失重10%的分解温度(Td10)均在340℃以上。产物具有良好的热回复性,可采用通用熔融成型加工设备对材料进行成型加工。氢键超分子聚合物具有延迟回复性能的软橡胶性质,在玻璃化温度(Tg)和熔融温度(Tm)之间表现为类橡胶弹性。氢键超分子聚合物熔体为具有很高屈服应力值的非线性Bingham流体。氢键超分子聚集体具有动态层状有序结构相和化学交联微区不均匀分布在三维网状结构无序相中的多相结构,在Tc1≈90℃下发生类弹性固-液相变,在Tc2处发生液-液转变的微相分离。氢键超分子聚合物的松弛过程是物理作用的缔合-解缔合机理和蠕动机理共同影响的结果。平均松弛时间均随着温度的升高而不断缩短,零剪切粘度也随着温度的升高而不断降低。高温下酰胺低聚物分子链之间的氢键密度很低,体系表现为低粘度液体；降温过程中,氢键密度增加,分子链之间通过多元氢键作用自组装,分子链有序性增加；在90℃左右,体系粘度、储存模量突然增加,氢键超分子聚合物发生液-固转变；由90℃继续冷却,三维氢键网络中形成少量层状动态有序结构,室温时氢键超分子聚合物体现为粘弹性固体,具有一定结晶性和良好的机械性能。在升温、降温的过程中,物理交联网状结构破坏与重组,氢键自组装过程具有可逆性。更多还原

【Abstract】 In this thesis, new thermorebersible multiple hydrogen-bonding supramolecualr polymers are designed and synthesized from the concept that multiple hydrogen-bonding supramolecular elastomers with physical network structure are assembled from small molecules or oligomers associated by hydrogen bonds. Hydrogen-bonding supramolecular polymers are successfully prepared by one-pot synthesis from a series of amide and end-capped amide oligomer assembled by multiple hydrogen bonds between chains. Molecular structure, molecular weight and distribution, as well as mechanical, crystallization and melting, thermal decomposition, thermoreversible and processing, rubber-like, dynamical rheological properties are well characterized. The mode for phase transition, chain dynamics, hydrogen-bonding thermodynamics and assembling mechanism of multiple hydrogen-bonding supramolecular polymers are proposed and discussed in this thesis.Amide oligomer BX-1-EAH and end-capped amide oligomers BX-1-EAH-PTSI and BX-4-EAH-PTSI are synthesized from the condensation polymerization of dimer fatty acid (DFA) and anhydrous ethylene diamine (EAH) and then end-capped reaction by adding to p-toluenesulfonyl isocyanate (PTSI) with variable kinds of dimer fatty acid (BX-1 and BX-4) and contents of isocyanate. At cooling of products, oligomer chains assemble to physical network hydrogen-bonding supramolecular polymer by multiple hydrogen-bonding connections between chains.1H-NMR and FT-IR analyses conform that amidation reaction and isocyanate end-capped reaction are successful and multiple hydrogen bonds of CO……NH, S=O……NH between amide and sulfonyl urea groups exist in the hydrogen-bonding supramolecular assembly which indicates the hydrogen-bonding physical network structure of supramolecular polymer. GPC and ESI-TOF-MS characterization show that amide oligomers have low molecular weight and wide molecular weight distribution and polymerization degree of the three oligomers is below 10.Highest ensile strength 13.2 MPa and ball indentation hardness 20.3 N/mm2 indicate that hydrogen-bonding supramolecular polymers have excellent mechanical properties. When molar ratio of EAH and DFA is 1.2:1, tensile strength and elongation reach the highest value. Hydrogen-bonding supramolecular polymer with BX-4 as starting materials has 3.2% indissoluble gel and more chemical crosslinking micro-region from branching, and has higher tensile strength modulus and hardness. Physical network and chemical crosslinking micro-region coexist in hydrogen- bonding supramolecular polymers. DMA results indicate that at low temperature (<-30℃) hydrogen-bonding supramolecular polymers behave like hard plastic at glass state and the glass transition is at around 10℃. Products show high-elastic properties between Tg and room temperature and rubber-like behavior at room temperature.DSC and WXRD results indicate the low melt temperature (88-100℃) and degree of crystalline (△Hm= 8.5-12.5J/g); TGA show the excellent thermal stability of supramolecular polymer and the 10% decomposition temperature (Td10) is> 340℃. The materials have good thermoreversible behavior, hence the moulding process can be operated on general melting mouldling processing equipments. Force-free tensile test indicates that the hydrogen-bonding supramolecular polymers behave like soft rubber with delayed recovery and show rubber-like elasticity between Tg and Tm.Rotational rheological characterization indicates that the melt of hydrogen- bonding supramolecuar polymer behaves like non-linear Bingham flow with very high yield stress. Hydrogen-bonding supramolecular assembly has multi phases including dynamic lamellar ordered phase and 3D network disordered phase with heterogeneous chemical crosslinking micro-regions. Rubber-like solid-liquid transition is at Tc1≈90℃, and liquid-liquid transition of micro-phase separation is at Tc2. Associate-disassociate mechanism of physical interaction and reptation mechanism have cooperatively effect on the relaxation of hydrogen-bonding supramolecular polymer. The mean time of relaxation decreases and the zero shear viscosity with the increase of temperature.At high temperature, the density of hydrogen bonds between oligomer chains is very low, and the system behaves like liquid with low viscosity; at cooling, the hydrogen-bonding density increases, molecular chains assemble by multiple hydrogen-bonding and the order degree of chains increases; viscosity and storage modulus of the system suddenly increases at around 90℃, and the supramolecular polymer has liquid-solid transition; below 90℃, a few dynamic ordered lamellar structures form in the 3D hydrogen-bonding networks, and until room temperature, hydrogen-bonding supramolecular polymer behaves like viscoelastic solid with low crystalline and good mechanical properties. At the heating and cooling cycles, physical cross-linking networks are destroyed and reformed, therefore, the assembling process from hydrogen-bonding is reversible.更多还原