【作者】 孙伟；

【导师】 周向东；

【作者基本信息】 苏州大学 ， 材料与化工（专业学位）， 2024， 硕士

【摘要】 尽管自修复的水性聚氨酯(WPU)材料已被广大的人们所熟知并且开始在皮革装饰、功能材料等行业进行初级的运用,但是,目前这种材料仍有许多需要改进的地方:(1)由于强烈的外界刺激,它可能会导致材料的化学结构受损,从而引起材料的降解和衰退;(2)它的修复周期、物理特性与修复效果往往无法达到平衡;(3)由于其制备方法与步骤的复杂性,它的制备过程可能需要更长的时间。对工业化生产并无益处。针对上述问题,本课题以水性聚氨酯为基材,分别将含有受阻脲键(NH-DF)的扩链剂以及含有四重氢键的扩链剂(UPY)和硼酸双甘油酯(HBA)嵌入到水性聚氨酯的分子链段中,制备出两种新型的自修复水性聚氨酯,然后制作成涂层胶刮涂整理到皮革表面。由于聚氨酯的氨基甲酸酯结构和皮革表面的氨基酸结构类似,所以聚氨酯整理到皮革表面具有较好的牢度和耐磨性。具体研究的内容和结果如下:(1)以富马酸二乙酯(DEF),1,6-己二胺(HDA)为原料,通过迈克尔加成反应,合成了一种侧链含有含受阻脲键的扩链剂(NH-DF),优化后的合成工艺条件为:反应温度为80℃,反应时间为24 h,n(DEF):n(HDA)为2:1,产出的NH-DF产率是81.8%,相对分子质量是460.79,生成状态是淡黄色粘稠液体。(2)将不同质量的NH-DF扩链剂添加到聚己内酯二醇1000(PCL1000)和异佛尔酮二异氰酸酯(IPDI)反应生成的预聚体中,再以2,2-二羟甲基丁酸(DMBA)为亲水扩链剂,丁酮肟(EMKO)为封端剂,采用预聚体法合成出不同NH-DF用量的自修复水性聚氨酯(NWPUs),探究了不同NH-DF用量对NWPU性能的影响,然后将NWPU_S制备成涂层胶整理到皮革上,对整理前后皮革的性能进行测试分析,结果表明NWPU1的自修复效果较好,在室温环境下经过2 h的放置,表面划痕基本消失,并对整理前后皮革的表面形貌和性能进行了分析。(3)以碳酸胍和α-乙酰基丁内酯为原料合成了一种含有四重氢键结构的中间体(UPY),其优化后的合成工艺条件为:碳酸胍和α-乙酰基丁内酯的物质的量之比为1:2,反应温度为80℃,反应时间为10 h,产物为白色粉末状固体。并通过核磁对其结构进行了表征。以硼酸(BA)和甘油为原料合成了一种含有硼酸酯基团的羟基化合物(HBA),其优化后的合成工艺条件为:BA和甘油的物质的量之比为1:2,反应温度和反应时间分别是180℃和3 h,产物为浅黄色透明粘稠液体,可溶于丙酮,并通过红外对其结构进行了表征。(4)将(3)中合成的两个中间体UPY和HBA按照一定的比例嵌入到由聚己内酯二醇1000(PCL1000)和异佛尔酮二异氰酸酯(IPDI)组成的预聚体中,随后加入亲水扩链剂2,2-二羟甲基丁酸(DMBA)和三乙胺(TEA)中和,再加入封端剂丁酮肟(EMKO),最后加水乳化制得自修复水性聚氨酯(HB-WPU)乳液。经过乳液稳定性和胶膜热稳定性测试,最后选用的聚氨酯为HB-WPU8,它具有较高的熔融焓,说明了它的储能具体合成条件为:预聚体R值为2.6,DMBA的用量为总反应物质量的5%,n(PCL1000):n(UPY):n(HBA)为5:1:2,通过对其显微镜观察以及对膜断裂修复前后拉伸强度的变化,测得它能够在室温下2～3 h即可修复划痕和自修复效率为89.29%。(5)将(4)中合成出的聚氨酯HB-WPU8混合约4 w t%的增稠剂660配置成涂层胶,并讨论单一因素下影响涂层整理的工艺,得到较佳的整理工艺为:烘焙时间120 s,烘焙温度130℃,随后对整理前后的皮革表面的形貌和性能进行了分析,结果说明整理后的皮革手感变得柔软,且有一定程度上使表面变得光滑,力学性能也比整理前更加好,最后用显微镜观察了皮革表面的划痕自修复过程,可以在4 h的时间里观察到皮革表面划痕的修复。更多还原

【Abstract】 Although self-repairing waterborne polyurethane(WPU)materials have been widely known and are beginning to be used in primary applications in industries such as leather decorating and functional materials,there are still many areas where this material needs to be improved:(1)due to strong external stimuli,it may lead to damage to the chemical structure of the material,which can lead to material degradation and decline;(2)its repair cycle,physical characteristics and restoration effect often cannot be balanced;(3)due to the complexity of its preparation methods and steps,its preparation process may take longer time.It is not beneficial to industrialized production.To address the above problems,the present work takes waterborne polyurethane as the substrate,and the chain extender containing hindered urea bond(NH-DF)and the chain extender containing tetraplex hydrogen bond(UPY)and bis-glycerol borate(HBA)are embedded into the molecular chain segments of waterborne polyurethane,respectively,to prepare two new types of self-repairing waterborne polyurethanes,which are then fabricated into a coating adhesive for scrape coating and finishing to the surface of the leather.Since the structure of urethane urethane and the amino acid structure of leather surface are similar,the polyurethane finishing to leather surface has better fastness and abrasion resistance.The contents and results of the specific research are as follows:(1)Using diethyl fumarate(DEF),1,6-hexanediamine(HDA)as the raw materials,a chain extender(NH-DF)containing hindered urea bonds in the side chain was synthesized by Michael addition reaction,and the optimized synthesis process conditions were as follows:the reaction temperature was 80℃,the reaction time was24 h,and the n(DEF):n(HDA)was 2:1,and the output yield of NH-DF was 81.8 The yield of NH-DF was 81.8%,the relative molecular mass was 460.79,and the resulting state was a light yellow viscous liquid.(2)Different masses of NH-DF chain extenders were added to the prepolymer generated by the reaction of polycaprolactone diol 1000(PCL1000)and isophorone diisocyanate(IPDI),and then dihydroxymethylbutyric acid(DMBA)was used as a hydrophilic chain extender and ebutylene ketone oxime(EMKO)as a capping agent,and the prepolymerization method was used to synthesize the self-repairing waterborne polyurethanes with different NH-DF dosages(NWPUs)by prepolymer method,and explored the effect of different NH-DF dosage on the performance of NWPUs,and then NWPUS was prepared as a coating adhesive finishing to leather,and the performance of leather before and after the finishing was tested and analyzed,and the results showed that the self-repairing effect of NWPU1 was better,and the surface scratches basically disappeared after 2 h of placing in the room temperature environment and the surface topography and performance of leather before and after the finishing were analyzed The surface morphology and properties of the leather before and after finishing were analyzed.(3)Guanidine carbonate andα-acetyl butyrolactone were used as raw materials to synthesize an intermediate(UPY)containing a quadruple hydrogen bonding structure,and the optimized synthesis process conditions were as follows:the ratio of the substance amounts of guanidine carbonate andα-acetyl butyrolactone was 1:2,the reaction temperature was 80℃,and the reaction time was 10 h,and the product was a white powdery solid.And its structure was characterized by NMR.A hydroxy compound(HBA)containing borate group was synthesized from boric acid(BA)and glycerol with the optimized synthetic process conditions of 1:2 ratio of the substance amounts of BA and glycerol,the reaction temperature and the reaction time of 180℃and 3 h,respectively,and the product was a light-yellow transparent viscous liquid,which could be soluble in acetone,and its structure was characterized by IR.(4)The two intermediates UPY and HBA synthesized in(3)were embedded into a prepolymer consisting of polycaprolactone diol 1000(PCL1000)and isophorone diisocyanate(IPDI)in a certain ratio,and then the hydrophilic chain extender 2,2-dihydroxymethylbutanoic acid(DMBA)and triethylamine(TEA)were added to neutralize the product,followed by addition of the capping agent butanone oxime(EMKO).Finally,the self-healing waterborne polyurethane(HB-WPU)emulsion was emulsified with water.After the emulsion stability and film thermal stability tests,the final polyurethane selected was HB-WPU8,which has a high enthalpy of melting,indicating its energy storage Specific synthesis conditions were as follows:the R-value of the pre-polymer was 2.6,the amount of DMBA was 5%,and the n(PCL1000):n(UPY):n(HBA)was 5:1:2 By microscopic observation and the change of tensile strength before and after the film break repair,it was determined that the polyurethane was the best choice for self-repairing.Through its microscopic observation and the change of tensile strength before and after membrane fracture repair,it was measured that it could repair scratches and self-repair efficiency of 89.29%in 2～3 h at room temperature.(5)will(4)synthesized polyurethane HB-WPU8 mixed with about 4 w t%of the thickener 660 configured as a coating adhesive,and discuss a single factor affects the coating finishing process,get the better finishing process for:baking time 120 s,baking temperature 130℃,and then before and after the finishing of the surface of the leather morphology and properties of the analysis,the results show that after the finishing of the leather feel become soft The results show that after finishing the leather feel becomes soft,and to a certain extent make the surface become smooth,mechanical properties are also better than before finishing,and finally with a microscope to observe the leather surface scratches self-repair process,can be observed in 4 h time to repair the leather surface scratches.更多还原