【作者】 张俊；

【导师】 陈国强；

【作者基本信息】 苏州大学 ， 纺织化学与染整工程， 2009， 博士

【摘要】 用含氟丙烯酸酯通过接枝共聚对真丝进行化学改性,如甲基丙烯酸三氟乙酯(G01)、甲基丙烯酸六氟丁酯(G02)、丙烯酸六氟丁酯(G03)、甲基丙烯酸十二氟庚酯(G06)、丙烯酸十二氟庚酯(G07)。此外,本文还合成了甲基丙烯酸八氟戊酯(G04)和丙烯酸八氟戊酯(G05)以及考察了上述7种接枝单体对真丝的反应性。同时,根据真丝的力学性能和热性能、染色性能、X-射线衍射、红外、拉曼光谱、双折射、扫描电镜、核磁共振、X–射线光电子能谱、氨基酸、折皱回复、白度、表面接触角等分析的结果来研究接枝真丝的结构与性能。用甲苯和对甲苯磺酸分别作为溶剂和催化剂,甲基丙烯酸或丙烯酸和八氟戊醇酯化分别合成出G04和G05。在较佳的合成条件下,G04和G05的收率分别是:42.5%和50%。这些产品的化学结构通过红外、核磁、气相色谱和元素分析获得了较好的结果,G04和G05的纯度分别高达96.46%和97.49%左右。含氟单体对真丝的接枝在过硫酸钾(KPS)为引发剂的复配乳化液中进行。实验中,综合预乳化液三种稳定性的测定结果,预乳化实验较佳配方为:氟碳表面活性剂FSO 12%(owm)、DF-10 8%(owm)、吐温80 30%。接枝条件如单体、引发剂、PH、温度和时间对接枝率的影响进行了测试。较佳的接枝条件是:单体100～150%(owm)、KPS 1～3.5%(owm)、pH 3、75～80℃、100～120min。在50~80℃接枝的表观活化能对于G01、G02、G03、G04、G05、G06和G07分别为:8.99、13.97、15.28、11.96、14.21、15.66和23.8 kJ/mol。根据实验数据得到了动力学接枝方程。用含氟单体接枝真丝的吸湿性与接枝率成线性反比例关系,而其细度与接枝率成线性正比例关系。接枝能提高真丝织物折皱回复性,特别是湿态的情况下更明显,根据接枝前后织物在NaOH水溶液中的溶解度,接枝提高了真丝的耐碱性。真丝织物接枝后引起其酸性和活性染料上染性与白度下降。真丝织物白度值的下降与引发剂浓度和温度的提高有关,表明引发剂促使大分子自由基的形成,对织物白度下降起了主要作用。同时,接枝处理后,真丝的断裂强度、断裂伸长率和透气性均有所下降。DSC和TG分析结果表明接枝真丝的分解峰的位置向高温移动,说明接枝真丝的热稳定性提高。由于真丝的大分子和含氟单体交联限制了大分子的运动,因此动态粘弹谱测定的损耗模量(E’’)的峰随着接枝率的增加而变低,并且峰的初始位置向高温移动。氨基酸分析结果表明含氟单体接枝主要在真丝大分子中酪氨酸、精氨酸和谷氨酸的-NH2、-OH和-NH-活性基团上。通过X射线衍射和双折射分析,含氟单体接枝真丝并不直接影响真丝的结晶区,但引起真丝大分子平均取向度的下降。接枝真丝的红外光谱显示出真丝具有β折叠结构和单体高聚物的结构特征峰,从而说明单体接枝在纤维的无定型区内部进行。在低接枝率(小于35%)范围,真丝经单体接枝后纵向表面形态和横向表面形态与没有接枝真丝相比无明显的变化,仅横截面变大,而在高接枝率范围内,真丝纤维周围覆盖了一层高聚物,并且出现分纤现象,随着接枝率的提高,这种现象更加明显。此外,真丝接枝后的核磁共振谱(19F)图表明,化学位移δ为-78.16ppm处、-215.71ppm和-122.51ppm处的吸收峰分别显示出分子具有–CF3、–CF2–和–CFH–结构,且经XPS谱图测定,改性后的真丝表面在结合能位于688.92ev处、284ev处、289ev处、291ev处和294ev处的峰分别归属于C–F键、C–H键、CFH键、CF2键和CF3键,这说明含氟单体已经和真丝发生了接枝反应,含氟侧链已经覆盖或分布在织物表面上。随着单体接枝率的逐渐升高,织物表面接触角逐渐增大,但趋势逐渐放缓,当接枝率过高时,反而会使接触角下降。此外,还发现带甲基的单体在相近接枝率下比不带甲基单体的接触角大,随着含氟碳链的增长,织物获得较高接触角所需要的接枝率也越来越低。经过多次水洗后,接枝后的真丝仍然具有较高的接触角,并且随着单体含氟碳链的增长,耐洗牢度进一步提高。总之,通过G04和G05的合成及七种含氟丙烯酸酯单体对真丝的接枝反应性以及接枝后真丝的结构与性能的研究,为真丝的化学改性及化学整理提供了基础。更多还原

【Abstract】 Silk fibers were chemically modified by grafting copolymerization with acrylate series monomers containing fluorine such as trifluoroethyl methacrylate(G01), hexafluorobutyl methacryate(G02), hexafluorobutyl acrylate(G03), dodecafluoroheptyl methacrylate(G06), dodecafluoroheptyl acrylate(G07). In addition, we synthesized octafluoropentyl meth- acrylate (G04) and octafluoropentyl acrylate (G05) for modification of silk fibers and examined the reactivity of these above seven grafting agents toward silk fibers. Mean while, we investigated the structure and properties of these grafted silk fibers in relation to the graft yield on the basis of the results of mechanics properties as well as thermal properties, dyeing properties, X-ray diffraction, IR, Raman spectrum, birefringence(△n), SEM, NMR, XPS, amino acid, wrinkle recovery, whiteness, surface contact angle, and so on analyses.Using toluene and p-toluene sulphonic acid as solvent and catalyst respectively, Methacrylic acd or acrylic acd and octafluoropentanol were esterified respectively to produce G04 and G05. Under the optimum synthesis conditions the yields of G04 and G05 are 42.5% and 50% respectively. The chemical structures of these products were analyzed by IR, NMR, gas chromatography and elementary analysis so that good results were obtained.The grafting of acrylate monomers containing fluorine onto silk fibers in composite emulsified liquid system using potassium persulfate(KPS) as initiator was investigated. The formulation of the pre-emulsification was optimized by studying three stabilities of different pre-emulsification liquid, namely, fluorocarbon surfactant FSO 12% (owm), DF-10 8% (owm), Tween 80 30%(owm). Effects of grafting conditions, such as concentrations of monomers, initiators, pH, temperature and time, on the graft yield were determined. The optimum graft conditions were found (Monomer 100-150%(owm), KPS 1-3.5%(owm), pH 3, 75-80℃, 100-120min). The activation energy of grafting at 50~80℃was found to be 8.99 kJ/mol for G01, 13.97 kJ/mol for G02, 15.28 kJ/mol for G03, 11.96 kJ/mol for G04, 14.21kJ/mol for G05, 15.66 kJ/mol for G06, 23.8 kJ/mol for G07.Grafting equations also were counted. The moisture regain of silk fibers grafted with acrylate monomers containing fluorine decreased linearly as the graft yield, while the size of the silk fibers increased linearly as the graft yield. The grafted silk fabrics showed greatly improved wrinkle recovery behavior, especially in wet state and resistance to alkaline according to the solubility of the silk fibers in NaOH aqueous solution. The grafting of silk fabric caused a little reduction of acid and reactive dye uptakes as well as whiteness. By treating silk fabric with KPS, in the absence of a monomer the whiteness values decreased linearly with increasing both initiator concentration and treatment temperature, indicating that the initiator plays a specific role in decreasing silk whiteness through macro-free radical formation. At the same time, after the grafting treatment with fluoride monomers, the breaking strength, elongation at break and air permeability of grafted silk fibers all decreased. The DSC and TG results showed that the position of decomposition peak of grafted silk fibers shifted to higher temperatures, suggesting the more thermal stability. The cross-linkage between the molecule of silk fibers and fluoride monomers may limit macromolecular motion in silk fibers, so, the peak of loss modulus(E’’) determined by dynamic viscoelastic measurements become lower and the initial position of this peak shifted to higher temperature, when the silk fibers graft yield increased. The amion acid analysis indicated fluoride monomers were inclined to graft with TYR, ARG and GLU of silk fibers which had some reactive groups, i.e., the hydroxyl, amido and imine groups acting as the center of reactive activities. X-ray diffraction patterns and Birefringence(△n) of silk fibers suggested that the grafting of fluoride monomers does not affect directly the crystalline regions, but causes a decrease of macro-molecular average orientation in the amorphous regions. The IR of the grafted silk fibers had overlapped absorption bands due to the molecular conformation of this fiber and monomer polymers, giving evidence that the monomer grafting occurred inside the amorphous areas of silk fibers. When the graft yields are more than 35%, the surface of silk fibers showed the presence of several granules, consisting of monomer polymers, and the cross-sectional area of silk fibers showed the appearance of separating fiber.Moreover, the NMR spectrum(19F)of grafted fibers indicated the chemical shifts of -78.16ppm, -215.71ppm and -122.51ppm represented the structures of–CF3,–CF2– and–CFH– of macromolecules of grafted fibers respectively. Furthermore, the XPS spectrum(19F)of grafted fibers also showed the binding energy positions of 688.92ev, 284ev, 289ev, 291ev and 294ev belonged to C–F, C–H, CFH, CF2 and CF3 structures respectively, which gave evidence that acrylate monomers containing fluorine had grafted with silk fibers and side chain structures containing fluorine had been covered or distributed on the surface of fabrics. With the increase of graft yields gradually, the surface contact angle of fabrics increased correspondingly and showed the trend of a gradual slowdown. When the grafting yield reached a certain value, if it is further increased, the contact angle will decrease. Besides, the contact angles of monomers with methyl structure are bigger than those of non- methyl monomers under the condition of similar graft yields. With the growth of fluorocarbon chain, the higher contact angle of fabric is, the lower grafting yield is needed. After washing many times, the grafted silk fibers still took on higher contact angle and with the growth of fluorocarbon chain of monomer, the washing fastness was improved. In a word, through the syntheses of G04 and G05 and the study of seven acrylate monomers containing fluorine reacting to silk as well as the research of structure and properties of grafted silk, the paper provides a basis for chemical modification and finishing of silk.更多还原