【作者】 郭睿威；

【导师】 姚康德；

【作者基本信息】 天津大学 ， 生物医学工程， 2003， 博士

【摘要】 聚合物聚醚多元醇（PPOC）是由微米级聚合物粒子在聚醚多元醇中原位形成的稳定粒子分散体，它为聚醚材料的粒子增强提供了方便的途径。本文以苯乙烯/丙烯腈在聚醚中分散聚合制备高固含量（45%）PPOC，研究了其形成、稳定和粘度的控制规律。采用间歇、连续工艺制备了高固含、低粘度的稳定PPOC，且将它用于聚醚聚氨酯水凝胶的合成，实现了水凝胶的粒子增强。为考察稳定剂结构对PPOC分散稳定性的影响，合成了不同结构的丁烯二酸聚醚酯大分子单体（MM），以GPC、NMR和双键滴定等方法表征了MM，阐明了MM结构与分散稳定间的关系，结果表明MM的分子量、不饱和链端结构、及其与聚醚连续介质的匹配性是影响其稳定效能的主要因素。在此基础上，合成了新型大分子单体稳定剂-反丁烯二酸聚醚酯（HFM）。以HFM为分散稳定剂，对比研究了半连续、种子法和连续聚合参数对PPOC稳定性和粘度的影响规律，用SEM、动态光散射测定了各条件下分散粒子的形态与粒径。研究表明，聚合过程中内外相聚合比例对PPOC中分散粒子的稳定性和粒径有着重要的影响。PPOC流变行为研究表明，保持PPOC稳定时，分散粒子的粒径和分布则是PPOC粘度的控制因素，因小粒径粒子对PPOC增粘有较大的作用，从而大粒径和宽分布的粒子设计和制备是合成低粘度PPOC的关键。通过优化，制得了固含量为45%、粘度在5500-6000mPa.s的PPOC。用全吸附/解吸液-固色谱法（FAD）分离了原位形成的PSAN-g-PPO接枝物，并用UV和1H-NMR对其进行了表征。结合动态光散射跟综分散体形成过程中粒径的变化规律，确认接枝物成核为主的聚合特征。以三官能度聚环氧乙烷共聚醚多元醇为原料，合成了稳定的亲水聚醚PPOC，与TDI和不同聚醚二醇扩链剂制备粒子增强的聚醚聚氨酯水凝胶，考察不同交联度、不同粒子填充量对水凝胶吸水率和力学性能的影响。结果表明：随PSAN粒子加入量的增加，PU弹性体和PU水凝胶的拉伸强度和断裂伸长同时增加；而水凝胶的吸水率降低，粒子增强效应明显。通过改变PSAN加入量和交联度，在相同吸水率（250%）下合成PU聚醚水凝胶的拉伸强度为0.75MPa、断裂伸长为120%，而聚醚PU水凝胶则0.22MPa和42%。更多还原

【Abstract】 Polymer polyether polyol composites (PPOCs), which are stable dispersions of glassy polymers in polyether polyols, provide a feasible method for particle reinforcement of polyether materials. In this work, the PPOC with high solid content of 45% were prepared by dispersion copolymerization of styrene (St) and acrylonitrile (AN) in polyether polyols with macromonomer as a stabilizer precursor in both semi-batch and continuous processes. The characters of formation, stability and viscosity of the dispersion were studied. Preparing conditions for stable PPOC with low viscosity and high solid content were opimized. Moreover a hydrophilic PPOC was used to prepare polyether polyurethane hydrogels in order to realize particle reinforcing hydrogels.For the purpose of examining the effect of structure of macromonomers on their stabilizing ability for the PPOC, various macromonomers (MM) were synthesized by reacting polyether with various relative molecular mass (RMM) with maleic anhydride at different temperature or fumarate monoethyl chloride, and their stabilizing abilities were evaluated. The results showed that the RMM and terminal unsaturated structure of MM and the miscibility of MM with the dispersing medium (polyether) were the crucial factors for the stabilizing ability of MM. Therefore, a novel macromonomer (HFM) was synthesized through polyether extending reaction with toluene diisocyanate (TDI) and then reacting with fumarate monoethyl chloride. Using HFM as a stabilizer precursor, the effects of polymerization parameters on stability and viscosity of PPOCs were investigated in semi-batch, seeded-batch and continuous processes, respectively, while the corresponding particle shape and size distribution were determined by SEM and dynamic light scattering. The results indicated that the content of HFM and the relative ratio of polymerization in continuous phase and in particle phase played important roles on the stability of PPOC. The rheological behavior of the PPOC revealed that the particle size and distribution were the key factor for controlling the viscosity of PPOC and its non-Newtonian behavior without particle aggregation, because too much small particles increase the viscosity of PPOC. So PPOC with low viscosity can be obtained in two-reactor continuous process, which can produce PPOC with large particle size with wide distribution. By optimizing, the PPOC with solid content of 45% and viscosity of 5500-6000mPa.s was obtained. <WP=4>The stabilizer, graft polymer PSAN-g-polyether, formed in situ was separated by a full-adsorption-desorption liquid-solid chromatograph method (FAD), and characterized by UV and NMR. Combined with the change profile of particle size in the formation process of the dispersion determined by dynamic light scattering, it is proved that the nucleation mechanism of aggregation of graft polymer is dominant in the semi-batch polymerization process.A hydrophilic PPOC was prepared by polymerizing St and AN in a trifunctional copolyether of ethylene oxide (EO) and propylene oxide with EO content of 78wt%. By reacting this PPOC with TDI and polyether diols, reinforced polyether polyurethane hydrogels were prepared. The effect of NCO index and the particle (PSAN) content on the degree of swelling (DS) in water and mechanical properties of the hydrogels were investigated. The data showed that there is effective particle reinforcing effect in both xerogel and hydrogel states. Increasing the PSAN particle content resulted in both increase in tensile strength and maximum elongation either for the xerogels or for hydrogels, meantime DS of hydrogels decreased. By adjusting the NCO index and the incorporated PSAN particle content, a reinforced polyether hydrogel was synthesized, it has an elongation of 120% and tensile strength of 0.75MPa at DS of 250%, while the polyether polyurethane hydrogel at the same DS exhibits elongation of 42% and tensile strength of 0.22MPa.更多还原