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季铵盐阳离子自乳化聚氨酯的合成及应用

The Synthesis of Self Emulsifying Hyamine Cationic PU and the Application

【作者】 郭超

【导师】 赵殊;

【作者基本信息】 东北林业大学 , 高分子化学与物理, 2011, 硕士

【摘要】 合成自乳化季铵盐阳离子水性聚氨酯,找到聚氨酯预聚步骤,扩链步骤,乳化步骤的各反应步骤的最佳条件,使得工艺简单,并能获得乳液性能稳定的聚氨酯乳液,是该研究的最主要目的。该论文以突破合成阳离子型聚氨酯反应条件选择的问题,找到经济,节约,能广泛普及的合成工艺为目标,并最终合成了稳定的阳离子型聚氨酯乳液。对于水性聚氨酯材料的耐水性耐溶剂性不足的缺点,交联改性法是解决这一难题的重要手段。本论文采用蓖麻油作为内交联剂进行内交联改性,成功的制备了内交联改性的阳离子型聚氨酯。另一方面,在能源日益枯竭的当今,采用可再生资源代替,也符合当今社会的发展。本研究主要以聚醚多元醇和二异氰酸酯,制备了含季铵盐基团的阳离子型聚氨酯乳液,采用PEG(400)与TDI进行预聚反应,以丙酮作为溶剂,控制—NCO:—OH比例在2:1~3:1时,可以得到容易控制的反应状态,并合成性能较优的聚氨酯乳液。实验表明聚氨酯预聚反应速率随温度升高和催化剂用量增大,呈现增长趋势,即在60℃,以及催化剂用量为1.0%时,反应迅速且平稳。对于阳离子型的水性聚氨酯在进行扩链反应,采取室温反应下,以丙酮稀释扩链剂后采用饥饿式滴加,控制MDEA的含量为体系质量的5%,这时反应体系平稳容易控制,且得到的乳液性能稳定。乳化过程采用低温乳化,降低中间体与水反应的几率;并以先中和后乳化的步骤,将中间体加入水中,降低搅拌速度,可以得到分散性好、气泡量低、性能稳定的聚氨酯乳液。另外针对聚氨酯材料耐水性的不足,本研究通过蓖麻油部分替代聚醚多元醇制备水性聚氨酯材料,使制备的聚氨酯具有一定的交联结构,从而改善材料的耐水性。实验中添加C.O.改性聚氨酯,可以改善PU的耐水性;在低交联度下,改性作用不明显,而在相对高的交联度下,C.O.可以明显改善PU的性能;当添加的C.O.与PEG物质的量比为3:7时,PU乳液可以达到一个较好的状态,并有着相对较高耐水性及耐溶剂性。将WPU与API主剂胶相混制备水性高分子异氰酸酯胶黏剂,测定由该胶制备胶合板的粘接性能。聚氨酯乳液与主剂相混时,以API主剂与乳液比例为5.4:2.3~5:2.9时其粘接性能最佳,湿剪切强度也有所提高。

【Abstract】 The main purpose of this study is to synthesize self-emulsified ionic polyurethane(PU), to find a better condition in prepolymerization, chain extend and emulsion reaction, to obtain a stable PU emulsion. This thesis is mainly to settle the choice of reaction conditions, to find the economical, widespread synthetic process, and finally synthesized the stable cationic PU emulsion.In addition, because of the weak of water resistance and solvent resistance in water borne polyurethane materials, the cross linking modification method is the important means to solve this problem. In this paper, castor oil was used to modify PU emulsion, and successfully synthesized the inside cross linked PU. On the other hand, using renewable resources instead is fit for the social development.The cationic PU emulsion, which contained hyamine, was synthesized by polyether diol and diisocyanate. The experiment results showed that the properties of PU emulsion was much better and the reaction was more easily controlled when the ratio of—NCO and—OH was 2:1-3:1 with PEG (400) and TDI as the main material, acetone as solvent. And the reaction rate increase obviously along with elevating temperature and raising the dosage of catalyzer. When the temperature is 60℃, the dosage of catalyzer is 1% in mass fraction of system, the system synthesize stably and speedily.The chain extender of cationic PU is a kind of catalyzer to the reaction. The experiments concluded that the reaction was stable and PU emulsion was good when it was taken at normal temperature, the amount of MDEA was 5% of the system and the chain extender was dropped hungrily.Emulsion course was a very important and hard step. The condition of the emulsion reaction was a key to the success of WPU synthesis. According to a large number of experimental results, the emulsification course should be taken under low temperature and low mixing speed. Thus it would be propitious to obtain stable latex.Further more, due to the lack of waterproof of PU, we used castor oil partly replacing polyether polyols in the PU. There was a crosslinked structure in PU so as to improve waterproof of the material. The results showed that the addition of CO. can really modify the property of PU. The modification was inconspicuous at low cross linked point. While at a relatively high cross linked point, the PU was obviously modified by CO.. When the mole ratio of PEG and CO. was 7:3, the PU emulsion could achieve a good state, and the properties were also high.We mixed the WPU and API, determined the adhesive properties and concluded that the bonding strength was better than simple API adhesive when the ratio of API and PU emulsion was 5.4:2.3-5:2.9.

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