| Micro fiber synthetic leather has soft and nature gloss, soft handle and strong sense of genuine leather. It has good adhesive properties with substrate, antiwear, flexing resistance, ageing resistance and other excellent performances. It also has great cold resistance, permeability, washability, easy manufacturing and low cost. Micro fiber synthetic leather is the most ideal substitute for natural leather. It is applied in clothing, shoes, bags, furniture and other industries. However, its disadvantages are also obvious, such as the short time of maintaining color, low fibrage density, low apparent density of base fabric, flat and thin handle, and so on. From the structural analysis, the active groups of micro fiber base are few which only accounts for about 10% of collagen fiber. Therefore, the colouring capability, hygroscopicity and moisture permeability of micro fiber synthetic leather are bad.Because of the novel structure, unique performance and potential application of hyperbranched polymer, it is paid more attention by researchers and it is regarded as an important developing direction of polymer science in 21st century. Hyperbranched polymer has low viscosity, difficultly tangled chain, good solubility, a large number of active groups and other unique advantages. Compared with the general chemical, it has big terminal group functionality and high reactivity. Consequently, in order to improve the sanitary properties of micro fiber synthetic leather, the modification of micro fiber synthetic leather by hyperbranched polymer whose terminal groups were hydrophilic groups (such as hydroxyl, carboxyl) was studied.Firstly, N, N-diethylol-3-amine methylpropionate (AB2-type monomer) was obtained by the reaction of diethanolamine (DEA) and methacrylate (MA). The optimized synthesis conditions of AB2 type monomer were that MA was instilled into DEA, methanol was as solvent, n (DEA):n (MA) was 1:2 and reaction temperature was 3.5h. The variation of characteristic absorption peak intensity of methacrylate at 1640cm-1 was traced by React IR IC10 on-lien infrared spectrometer and the optimal reaction time of synthesizing N-diethylol-3-amine methylpropionate was determined to be 3h. The reaction order of this reagent was two and the activation energy equaled to 36.96kJ/mol.The hydroxyl-terminated hyperbranched polymer (HPAE-H) was synthezed by the reaction of trimethylolpropane and N-diethylol-3-amine methylpropionate under the catalysis of p-toluene sulphonic acid. The optimized synthesis conditions of HPAE-H were that monomer was instilled into nuclear matter, the temperature was 120℃, the dosage of catalyst was 2% and the reaction time was 5h. The IR,1H-NMR, GPC, DSC and TG were used to characterize the structure and properties of monomer and HPAE-H. The thermodynamic performance, solubility and surface activity of the third generation hydroxyl-terminated hyperbranched polymer (G3) were studied. The results showed that HPAE-H had good thermal stability, certain crystallization capacity; good dissolve ability in polar solvent and good surface activity after dissolving in water. Matrix breathing curve was used to study the biodegradability of hyperbranched polymer. The results showed that the first, second and third generation hydroxyl-terminated hyperbranched polymer (G1, G2, and G3) all could be biodegraded. Their difficult degree of biodegrading was that the G1>G2>G3.Secondly, maleic anhydride was used to modify HPAE-H and the carboxyl-terminated hyperbranched polymer (HPAE-C) was obtained. The optimum conditions were confirmed by single-factor experiment. The conditions were that the dosage of catalyst was 0.7%, n (OH):n (maleic anhydride) was 1:1.1, the reaction time was 4h and the temperature was 80℃. The IR,1H-NMR,13C-NMR and GPC were used to characterize the structure and relative molecular mass of HPAE-C. The thermal analysis of HPAE-C was carried out by DSC and TG. The results showed that HPAE-C had good thermal stability. The surface activity was studied by surface tension instrument and the results showed that HPAE-C had good surface activity. The surface tension would significantly decrease after adding a spot of HPAE-C into water. Moreover, with the increase of the dosage, there was reduce trend in surface tension.When the dosage of dye was 5%,8%,10%,15% and 20%, the micro fiber synthetic leather was treated by HPAE-C and HPAE-H whose dosage respectively were 1%,3%,5%,8% and 10%. The variation of thickness, area, permeability, moisture permeability and moisture absorption were studied. The results showed that the area of synthetic leather reduced, the thickness significantly increased and the air permeability had no change. Hyperbranched polymer had great influence on the moisture permeability and moisture absorption of synthetic leather. When the dosage of dye and HPAE-C respectively were 15% and 5%, the moisture permeability and moisture absorption respectively were 0.6327 mg/10cm2·24h and 0.03641mg/10cm2·24h, which respectively increased by 37.67% and 32.34% compared with the blank samples. When the dosage of dye and HPAE-H respectively were 20% and 10%, the moisture permeability and moisture absorption respectively were 0.5534 mg/10cm2·24h and 0.03641mg/10cm2·24h, which respectively increased by 33.6% and 32.31%. Compared with collagen hydrolysate and aluminum tannin, hyperbranched polymer had more effect on the moisture permeability and moisture absorption of synthetic leather. The scanning electron microscopic observation showed that hyperbranched polymer had contribution to the loose of synthetic leather fiber. It was propitious to increase the moisture permeability. Hyperbranched polymer made synthetic leather softer, which could be proved by the results of sensory testing.The binding form of hyperbranched polymer with polyamide was studied. The results showed that in the billing form of G3 and polyamide, the absorption deposition binding was predominant, the following was hydrogen bond and electrovalent bond and the covalent linkage was the least. In the billing form of HPAE-C with polyamide, the absorption deposition binding was predominant, the following was hydrogen bond and electrovalent bond and the covalent linkage was the least. This showed that the physisorption deposition was the main binding form. The DSC curves showed that compared with the peak temperature of polyamide, the peak temperature of polyamides treated by HPAE-H and HPAE-C both were reduced, which showed that hyperbranched polymer had reacted with polyamide.The binding form of hyperbranched polymer with micro fiber synthetic leather was studied. The results showed that the binding capacity of G3 increased with the increase of relative molecular weight. The adsorption deposition binding was the main form, the following was hydrogen bond and electrovalent bond and covalent bond was the least. When pH was 3.5, in the billing form of HPAE-C with micro fiber synthetic leather, the adsorption deposition was the main binding form, the following was hydrogen bond and electrovalent bond and covalent bond was the least. When pH was 7.0, in the billing form of HPAE-C with micro fiber synthetic leather, the adsorption deposition was the main binding mode, the following was hydrogen bond and electrovalent bond and covalent bond was the least. The DSC curves showed that compared with the peak temperature of micro fiber synthetic leather, the peak temperature of micro fiber synthetic leather treated by HPAE-H and HPAE-C both were reduced, which showed that hyperbranched polymer had reacted with micro fiber synthetic leather.Finally, HPAE-H and HPAE-C were used to modify micro fiber (non-figured islands-in-sea) synthetic leather. Then the application tests of the dyeing properties of micro fiber synthetic leather were carried out. The results showed that the dyeing rate of synthetic leather generally declined after adding hyperbranched polymer, the dry and wet rubbing fastness, tensile strength and tear strength of micro fiber fiber synthetic leather all increased after adding HPAE-H and HPAE-C. Compared with the effects of HPAE-H and HPAE-C on the dyeing properties of micro fiber synthetic leather, when the dye was S-BGL, the comprehensive evaluation results showed that the modification effect of HPAE-C was better than that of HPAE-H. When the dye was 2S-LD, the comprehensive evaluation results showed that the modification effect of HPAE-H was better than that of HPAE-C.The innovations of this thesis are that hyperbranched polymer is introduced into synthetic leather for the first time and the functional additive of micro fiber synthetic leather was prepared. The influence of hyperbranched polymer on the sanitation property of micro fiber synthetic leather was systematically studied for the first time and the binding form of hyperbranched polymer with micro fiber synthetic leather was investigated. The research fields of synthetic leather chemicals were broadened.
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