【作者】 郝晓丽；

【导师】 王学川；

【作者基本信息】 陕西科技大学 ， 应用化学， 2014， 博士

【摘要】 随着我国造纸行业的不断发展，施胶剂的消耗量正在逐年上升。生物质施胶剂由于其原料来源广泛、价格便宜、易于生物降解、可再生等优点，一直在造纸行业中长期占有较大的市场比例。因此，进一步研发新型生物质施胶剂产品或者拓展原有生物质施胶剂的改良产品具有重要的意义。本论文旨在以废弃皮胶原中提取的胶原蛋白为原材料，合成两种新型环保型造纸施胶剂，并对其结构和性能做了较为系统的研究，另外还研究了该类胶原蛋白基施胶剂在瓦楞原纸上的应用效果，这将为皮革行业固体废弃物的大宗资源化利用拓展一条新的途径，也为造纸行业开发新型的生物质施胶剂提供理论依据和支持。本论文的具体研究工作包括以下几个方面：第一方面，采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法(简称SDS电泳)、凝胶渗透色谱仪(GPC)和氨基酸分析仪对海宁德邦化工有限公司提供的胶原蛋白的相对分子质量分布、氨基酸种类和含量进行了测定，结果表明：该胶原蛋白的相对分子质量分布范围在600-80000Da，主要集中在低相对分子质量范围内，数均分子量为1123Da，重均分子量为3609Da；含有16种氨基酸，其中Pro和Gly含量最高，分别为17.84%和17.15%。总氨基酸含量为65.73%，纯度较低，但是其具备改性的结构要求，可作为生物质材料加以利用。第二方面，以该胶原蛋白作为接枝主链，以丙烯酸丁酯(BA)和苯乙烯(St)分别作为柔性侧链和刚性侧链，以过硫酸钾/亚硫酸氢钠为氧化还原引发体系，通过自由基聚合法制备一种综合施胶性能优异的接枝改性胶原蛋白(GMC)造纸施胶剂。以GMC产物的接枝率和沉淀率作为参考指标，设计单因素实验并确定其较优的制备条件为：m(胶原蛋白):m(总单体)为1:1，m(BA):m(St)为1:1.5，引发剂用量为单体总量的3%，反应时间为4h，GMC产物外观为泛蓝光白色乳液，固含量14.3%，粘度为30mPa·S，耐电解质和耐酸碱性好，且具有较好的储存稳定性。将最优条件下制备的产物提纯后，采用傅里叶红外光谱仪(FT-IR)对其结构进行表征，结果证明：接枝改性后胶原蛋白的酰胺Ⅰ、Ⅱ和Ⅲ带的特征吸收峰均发生了红移，结合饱和脂肪族中C=O和C-C(C=O)-O特征峰的出现以及苯环中5个H的特征吸收峰的出现，证明合成反应按照预期设计路线进行，得到了预期产物。采用扫描电镜(SEM)、透射电镜(TEM)和激光粒度分析仪对胶原蛋白接枝改性前后的形貌、接枝改性后的乳液形貌、粒径大小及分布进行测试，结果表明接枝改性破坏了胶原蛋白的颗粒结构的规整性，表面变得粗糙，白色部分为乙烯基类单体聚合物；接枝改性后乳液微观形貌为大小均一的球形结构，平均粒径约为117nm。采用X-射线衍射分析仪(XRD)、能量分散能谱分析仪(EDS)和差示扫描量热仪(DSC)对接枝改性前后胶原蛋白的结晶性、元素含量及其热稳定性进行表征，结果表明：接枝改性使得产物的结晶度降低，热稳定性提高；由于原材料提取过程中脱铬不完全，所以接枝改性产物中仍然含有微量铬，但并没有超过欧盟条约的限量，符合环保要求。以瓦楞原纸作为施胶对象，将合成的环保型GMC乳液用于其表面施胶，实验结果表明：其对瓦楞原纸的环压强度、抗张强度和抗水性均有大幅度提高，与工厂施胶纸张性能相当，其中环压指数为7.11N·m/g和抗张指数2.38KN/m，分别比原纸提高2.6和1.8倍，且获得了很强的抗水性；通过SEM观察了施胶前后纸张截面和表面的纤维形态，结果表明：用GMC乳液施胶后纸张截面和表面的纤维变得紧实、有序、光滑，证明GMC施胶乳液与纸张纤维之间存在相互作用，且起到了一定的施胶效果。将GMC乳液分别与两种常用的合成类施胶剂烷基烯酮二聚体(AKD)和苯乙烯-丙烯酸酯共聚物(SAE)复配使用，研究其协同施胶性能，实验结果表明：本实验制备的GMC乳液与商品SAE之间具有很明显的协同作用，两者复配施胶后纸张的环压强度和抗张指数都远远优于其他产品的施胶效果，环压指数和抗张指数比原纸分别提高了3.3和2.7倍；通过水接触角测定仪研究了不同施胶纸样的抗水性，结果表明：GMC乳液与商品SAE复配施胶的纸张抗水性最强，静态水接触角达到137.6°，与60s吸水值分析结果一致。第三方面，以胶原蛋白为原材料，以环氧氯丙烷(ECH)作为交联剂，对其进行交联改性；然后再以BA聚合物作为疏水链，以过硫酸钾/亚硫酸氢钠作为引发剂，对交联胶原蛋白(CLMC)进行接枝改性，得到一种交联-接枝改性胶原蛋白(CL-GMC)造纸施胶剂。以CLMC涂布纸张的60s吸水值作为参考指标，通过单因素实验确定交联反应的较优条件为：交联温度为50℃，体系pH为10，反应时间为3h，胶原蛋白质量浓度为20%，交联剂即ECH用量为胶原蛋白用量的6%；以CL-GMC乳液接枝率作为参考指标，通过单因素实验优化出接枝反应的较优条件为：m(BA):m(胶原蛋白)为1:2，引发剂用量为BA用量的4.5%，反应温度80℃，反应时间为3h；CL-GMC产物外观为泛蓝光白色乳液，固含量22.3%，粘度为45mPa·S，耐电解质和耐酸碱性好，且具有较好的储存稳定性。采用FT-IR和拉曼光谱仪对胶原蛋白、CLMC和CL-GMC的结构进行了表征，结合改性前后发生变化的红外特征吸收峰和拉曼特征谱带，证明用ECH和BA对胶原蛋白的交联改性和接枝改性均按照预期路线成功进行，合成出预期改性产物；通过激光粒度仪对CL-GMC乳液粒径大小和分布进行了表征，结果表明：其乳液粒径大小均一，平均粒径约为164.2nm。通过XRD、扫描电镜/能量分散能谱分析仪(SEM/EDS)、热重分析仪(TG)和DSC对交联-接枝改性前后产物的结晶性、形貌、元素含量和热性能进行了分析，测试结果表明：交联-接枝双重改性方法使得产物的结晶趋势明显降低，且胶原蛋白颗粒的规整结构被破坏，交联-接枝改性产物中仍含有微量铬，但并不会影响其应用。单纯GMC的热分解温度为240℃，而CL-GMC的热分解温度达到380℃，说明交联-接枝改性方法可更大幅度的提高胶原蛋白的热稳定性能。将CL-GMC乳液用于瓦楞原纸的表面施胶，通过SEM、TG和DSC对施胶前后的纸张性能进行了表征，结果发现施胶后纸张表面纤维明显变得紧实、有序、光滑，且纸张的热稳定性大幅度提高；以纸张的环压指数、抗张指数和60s吸水值作为考察指标，研究不同施胶纸样的施胶性能，结果表明：CL-GMC施胶纸张的环压指数和抗张指数都优于单纯GMC以及商品SAE与GMC复配施胶纸张的。将CL-GMC与商品SAE复配施胶后，施胶效果更好，纸张环压指数和抗张指数分别可达到10.82N·m/g和6.14KN/m，是单纯GMC施胶纸张环压指数的1.52和2.58倍。但CL-GMC施胶纸张的抗水性却低于GMC的施胶纸张，将其与商品SAE复配施胶后，纸张的60s吸水值可得到大幅度提升，均超过了其他三种施胶剂的抗水性。借助于水接触角测定仪分析不同施胶纸张的抗水性，结果与60s吸水值实验结果是一致的，CL-GMC施胶纸张的水接触角为111.1°，说明其抗水性能弱于GMC(123.7°)和SAE与GMC复配施胶纸张的(137.6°)。但是将CL-GMC与商品SAE复配施胶后，纸张的静态水接触角可达到155.7°，超过了商品SAE与GMC的复配施胶的纸张抗水性。将CL-GMC乳液单独作为纸张表面施胶剂或者与其他合成类施胶剂复配使用，均具有较好的综合性能，具有一定的工业化可行性。本文为新型环保型造纸施胶剂、板材黏合剂或其他领域的涂饰材料的开发提供了重要的理论依据及指导，并为皮革行业废弃胶原的资源化利用拓展了新的途径。更多还原

【Abstract】 With the continuous development of papermaking industry in ourcountry, the consumption of the sizing agentsis yearly on the increase.Biomass sizing agent has chronically taken up the larger market share inthe papermaking industry, owing to its extensive sources for rawmaterial, cheap cost, easily biodegradable and renewable. Therefore, itis very important to develop the novel biomass sizing agent product orexpand the modified products of the original biomass sizing agents.This paper aims to prepare two novel and environmental friendly papersizing agents with the collagen extracted from the reclaimed leatherwaste. Their structure and performance were studied systematically. Inaddition, their sizing effect was also studied by coating their on thecorrugated paper. It will expand a new way to largely recycling use ofleather waste for the leather industry, as well as provide a theoreticalbasis and support to develop new biomass for the paper industry. Mainstudied contents are as follows：The first, the relative molecular mass distribution, type and contentof amino acids of collagen from the Debang chemical Co. Ltd. inHaining are determined by the Sodium dodecyl sulphate-polyacrylamidegel electrophoresis (SDS electrophoresis), Gel permeationchromatograph(GPC) and Amino acid analyzer. The determined resultsshow that the relative molecular mass distribution of collagen is at600~80000and mainly concentrates in the low relative molecular massrange. Its number average molecular weight is1123Da and the heavymolecular weight is3609Da. It contains16types of amino acids. And the most content contains proline (Pro) and glycine (Gly), and theircontents are respectively17.84%and17.15%. The total content ofamino acids is65.73%and the purity of collagen is low. Being used asthe biomass material, the molecular chain of collagen still has the basicpropertiesof the natural collagen and its structure is in line with therequirements for the modification.The second, the grafting modified collagen(GMC) sizing agentwith excellent comprehensive sizing performance is prepared by freeradical polymerization, with collagen as the grafted main chain, Butylacrylate(BA) and Styrene(St) as the flexible and rigid side chains,potassium persulphate/sodium bisulfite as redox initiator system. Thegrafting modified collagen(GMC) with the excellent sizing performanceis prepared by the free radical polymerization method. With the graftingrate and precipitation rateof GMC product as the reference index, theprepared conditions are optimized by single factor experiment. Asfollows, m(collagen): m(monomers) is1:1, m(BA): m(St) is1:1.5, thedosage of initiator is3%of the total monomers, the reaction time is4h.The GMC product appears the white emulsion with blue light. Its solidcontent is14.3%and the viscosity is30mPa·s. The performance ofelectrolyte, acid and alkaliresistance and the storage stability are allexcellent. After purifying to GMC in the optimal prepared condition, itsstructure is characterized by Fourier transform infraredspectroscopy(FT-IR). Result explains the amideⅠ, Ⅱ, Ⅲ of collagenare slightly shifted to higher wavenumber and the characteristicabsorption peaks of C=O and C-C(C=O)-O from the saturated aliphaticand5H from the benzene ring are present, after grafting modification. Itproves that the synthesis reaction carry out in accordance with theexpected design route and the expected product is obtained.The morphology, particle size anddistribution of the collagen andGMC are determined by Scanning electron microscopy(SEM),Transmission electron microscopy(TEM) and Laser particle sizeanalyzer. Results show that the structure regularity of the collagengranule is destroyed by the grafting modification and its surface changes into roughness. These white parts belongs to the polymer ofvinyl monomers. The morphology of GMC emulsion is sphericalstructure with size uniformity and its mean particle size is117nm.The crystalline degree, element content and thermostability of thecollagen and GMC are characterized by X-raydiffractionanalyzer(XRD),Energy-dispersive spectrum analyzer(EDS) and Differential scanningcalorimeter(DSC). Results suggest crystalline degree declines andthermostability increases, after grafting modification. There is traces ofchromium in the GMC product，because the removal of chromium of thecollagen extracted from leather shavings was incomplete. But theamount of chromium in the product is less than limited that in the EUdirectives and meet the requirements of environmental safety.With corrugated base paper as the sizing object, GMC emulsion iscoated on its surface. Result of sizing experimental shows the ring crushstrength, the tensile strength and the water-resistance performance ofpaper sized by the GMC are improved significantly, which is nearly thesame as the factory sized papers. The ring crush index and tensile indexare respectively7.11N·m/g and2.38KN/m, being2.6and1.8timesmore than that of base paper. The water resistance performanceenhances greatly. The morphology of fibers in cross-section and surfaceof paper sized before and after is observed by SEM. Results indicatethat fibers of the sized paper are tight,orderly and smooth. It proves thatthe GMC sizing agent emulsion interacts with paper fiber and producesthe sizing effect.The synergistic sizing effect between GMC sizing agent and thecommercial synthetic sizing agents such as alkyl ketene dimers(AKD)and styrene-acrylate copolymer(SAE) is studied. The experimentalresults suggest that the synergy between GMC and SAE is prominent.The ring crush strength and tensile strength of sized paper by the mixedsizing liquid are much better than that of others. The ring crush indexand tensile index are respectively3.3and2.7times more than that ofbase paper. The water resistance performance of the different sized papers is determined by the water contact angle meter. Results showthat the water resistance performance of sized paper by the mixture ofGMC and SAE is strongest and the static water contact angle gets to137.6°. It is consistent with the determined results of value of waterabsorbing for60s.The third, cross-linking modified by the epichlorohydrin(ECH) asthe cross-linked agent and grafting modified by BA as the hydrophobicchain and potassium persulphate/sodium bisulfite as the initiator, thecross-linking/grafting modified collagen(CL-GMC) sizing agent isprepared. The separated and purified product is characterized by thesemodern instrumental analysis methods. With the value of waterabsorbing of sized paper by the cross-linking modified collagen(CLMC)liquid as the reference index, the cross-linking reaction conditions areoptimized by single factor experiment. As follows, the cross-linkingtemperature is50℃, pH is10, the reaction time is3h, the massconcentration of collagen is20%, the dosage of ECH is6%of that ofcollagen. With the grafting rate of CL-GMC as the reference index, thegrafting reaction conditions are optimized by single factor experiment.As follows, m(BA):m(collagen) is1:2, the dosage of initiator is4.5%ofthat of BA, the reaction temperature is80℃, the reaction time is3h.The CL-GMC sizing agent also appears a white emulsion with blue light.The solid content is22.3%and the viscosity is45mPa· s. Theperformance of electrolyte, acid and alkaliresistance and the storagestability are also excellent.The structure of collagen and CL-GMC product is characterized byFT-IR and Raman spectrometer. Results imply that cross-linked/graftedmodified to collagen by the ECH and BA successfully carry outaccording to the expected route, combining characteristic absorptionpeak of FT-IR and Raman. And the expected modified product is gotten.The particle size anddistribution of the CL-GMC emulsion isdetermined by the Laser particle size analyzer. Results show that theparticle size of CL-GMC emulsion is uniform and the mean particle sizeis164.2nm. The crystalline degree, morphology, element content andthermostability of collagen modified before and after are characterizedand analyzed by XRD, SEM/EDS, TG and DSC. Results suggest that thecrystalline trend of the CL-GMC product declines obviously and thestructure regularity of the collagen granule is destroyed by thecross-linking/grafting modification. Although there is traces ofchromium in the CL-GMC product, it would not affect their application.The thermal decomposition temperature of GMC is240℃. It increasesto380℃by the cross-linking/grafting modification. It suggests that theimprovement of thermostability for CL-GMC is more significant thanthat ofthe GMC.Coating CL-GMC emulsion on surface of the corrugated basepaper, the performance of paper sized before and after is characterizedby SEM, TG and DSC. The result shows that the paper fiber is tight,orderly and smooth, and thermal stability of the sized paper alsoimproves. With the ring crush index, the tensile index and the value ofwater absorbing as the review indicators, the sizing performance of thedifferent sized papers is studied. Results states that the ring crush indexand the tensile index of the paper sized by CL-GMC are superior to thatof paper sized by GMC and the mixture of SAE and GMC. Mixed theCL-GMC with SAE as the sizing agent, the sizing effect is better. Thering crush index and the tensile index respectively get to10.82N·m/gand6.14KN/m, and are1.52and2.58times more than that of the sizedpaper by the GMC. But the water resistance performance of the sizedpaper by CL-GMC is inferior to that of the sized paper by GMC. Thevalue of water absorbing improves drastically and surpasses to the othersized papers, mixing CL-GMC with SAE as the sizing agent.The water resistance performance of the different sized papers isanalyzed by the water contact angle meter. Result is consistent with thatof the value of water absorbing. The static water contact angle of thesized paper by CL-GMC is111.1°. Its water resistance performance isinferior to that of the sized paper by the GMC(123.7°) and the mixtureof SAE and GMC(137.6°). The static water contact angle of the sized paper by the mixture of CL-GMC and SAE gets to155.7°. Thecomprehensive sizing performance of the sized papers is good, withCL-GMC or the mixture of CL-GMC and other synthetic sizing agentsas surface sizing agent. It has a certain feasibility for industrialization.In this paper, it not only provides the important theory basis andguidance for developing the novel paper sizing agent, board bindingagent or other coating material, but also opens up the reliable way forrecyclinguse of the chromewaste collagen in the leather industry.更多还原