新型互穿网络聚合物对纸张增强性能的影响

以聚酰胺多胺环氧氯丙烷(PAE)溶液为反应介质,过硫酸铵为引发剂,丙烯酰胺(AM)、甲基丙烯酸缩水甘油酯(GMA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,采用自由基聚合的方法制备出阳离子型CPAM/PAE顺序互穿网络聚合物(IPN)。红外光谱图表明自由基单体聚合成功;SEM扫描电镜图显示,不同比例复配的PAE和CPAM混合物呈空间网络交联结构。研究表明,当ω(PAE)=60.56%,ω(AM)=2.42%,ω(DMC)=2.42%,聚合温度为70℃,时间为3h的条件下合成固含量为30%的阳离子互穿网络聚合物应用于纸张中,IPN添加量为1%,能提高纸张干抗张指数17.44%,湿抗张指数26.78%,撕裂指数39.84%,耐折度71.94%,耐破指数41.49%。     

瓦楞纸板在线增强技术

为了解决国产普通瓦楞原纸存在的质量问题,东经控股集团公司通过使用自行研制的水性增强剂,在瓦楞纸板生产线生产过程中,对国产普通瓦楞原纸进行喷涂处理,在线增强来提高国产低克重,低质量瓦楞纸的韧度和强度.经实际使用,具有明显的效果.阐述了该技术的研制过程.     

生物降解聚合物复合浸渍纸——造纸增强剂的增强作用与生物降解性评价

用生物降解聚合物（BP）制备复合浸渍纸，研究了其物理性能及生物降解性。将原纸浸在BP乳液中，于100℃固化20min。相同质量复合浸渍纸其湿强度随BP含量的增加显著增加，干强度仅有一定程度的增加。添加0．5％通用造纸湿强剂——聚酰胺环氧氯丙烷（PAE）树脂可增加复合浸渍纸的湿强性；其湿强度可达9．3MPa；所用BP与纸的比例为20：80。进一步提高性能可再加入聚乙烯基胺（PVAm）。当BP与纸的比例同样为20：80时，添加0．2％PVAm和0．5％PAE的复合浸渍纸的湿强度（拉伸）可提高27％，只加0．7％PAE复合浸渍纸的湿强度仅提高了3％～4％。由于PAE和PVAm的加入，复合浸渍纸的生物降解被推迟，但埋在土中60天后，复合浸渍纸的失重率可达到90％。未用添加剂的复合浸渍纸达到同样的失重率仅需45天，30天后还有原纸存在。     

两性聚丙烯酰胺纸张增强剂的合成和应用

研究了两性聚丙烯酰胺的合成、结构和性能。这种两性聚丙烯酰胺和纸纤维能够通过离子键和配位络合结合，形成较均一的交联网络，使纸张干强度明显增加，是一种新型和优异的纸张干强剂。     

高性能瓦楞纸箱

当前美国至少有13家瓦楞纸箱厂在制造高性能纸箱,这种纸箱的牛皮卡具有很高的密度,瓦楞原纸采取纤维与塑料相结合,这种新一代的运输包装不但能承受堆高时的压力,也不会因气候(炎热和潮湿)而影响其性能。     

阳离子丙烯酸酯共聚物乳液制备及对纸张增强性能的影响

使用丙烯腈、丙烯酸、丙烯酰胺、阳离子单体以及淀粉和阳离子淀粉,通过引发剂过硫酸铵的引发,用聚乙烯醇作为分散剂和保护剂,在80℃进行乳液共聚,反应时间为2h,制得多元阳离子丙烯酸酯共聚物乳液和阳离子丙烯酸酯共聚物接枝淀粉乳液增干强剂。这两类共聚物具有自乳化性,乳液pH值2.0～5.0,粘度700mPa.s～1500mPa.s,Zeta电位20mV～40mV。可用作造纸增干强剂。用IR、DSC等手段对增干强剂的结构和性能进行了表征。应用试验表明,制备的两种增干强剂对提高纸的干强度、环压指数有明显的效果。     

颜料协同作用对涂布装饰原纸性能的影响

目的研究颜料协同作用对装饰原纸性能的影响,达到改善纸张表面结构、优化其物理性能的目的。方法优选阔叶木浆和针叶木浆(有效成分的绝对质量比为4∶1)混合打浆至打浆度(SR)38°,再添加二氧化钛填料、PAM、PAE、硫酸铝等抄造装饰原纸;以PVA、阳离子淀粉为胶黏剂,加以蒸馏水、颜料(TiO_2分别与Al_2O_3,Clay,Al_2SiO_5,SiO_2协同)、分散剂、消泡剂、润滑剂、保水剂制备用于装饰纸表面用涂料,采用涂布机和压光机对原纸进行涂布压光,之后浸渍压板,采用凹版进行印刷,探究颜料复配涂布对原纸涂层结构和印刷适性作用。结果颜料协同改性中添加一定的SiO_2颜料有助于纸张表面被有效均匀地涂覆,并能观察到细小的颜料颗粒,形成良好紧密涂层结构,装饰原纸涂布含有SiO_2协同作用颜料后,吸水高度提高了135%,平滑度提高了130%,干抗张强度提高了175%,湿抗张强度提高了160%。印刷性能方面,协同改性添加SiO_2涂料涂布装饰原纸在相对较小的涂层厚度下纸张涂层具有良好的油墨接受性,有助于印刷油墨的吸收固着,进而抑制网点扩大和颜色整体阶调再现范围变大。结论颜料协同改性涂布添加SiO_2有助于改善装饰原纸的物理性能和印刷适性。     

热压温度对芳纶1414纤维/1313浆粕复合纸微区结合特征的影响

针对国产间位芳纶纸力学性能不足的问题,采用芳纶1414(聚对苯二甲酰对苯二胺)短切纤维与芳纶1313(聚间苯二甲酰间苯二胺)浆粕复合,制备芳纶1414纤维/1313浆粕复合纸,研究不同温度下芳纶1414纤维/1313浆粕复合原纸的热压性能,分析纸张的强度性能;采用SEM、压汞仪和FTIR研究芳纶1414纤维/1313浆粕复合纸的内部结构变化。阐述热压温度对芳纶1414纤维/1313浆粕复合纸热压过程中短切纤维与浆粕之间的相互作用以及微区结合特征的影响。结果表明:芳纶1414纤维/1313浆粕复合纸在热压温度为280℃、热压时间为6min、热压压力为15 MPa条件下,短切纤维与浆粕之间黏结状态良好,自制芳纶1414纤维/1313浆粕复合纸孔隙率为23.21%,其抗张指数最大值为212.2N·m·g~(-1),为Nomex T410纸强度的两倍。FTIR结果表明,随着热压温度的升高,纸张中未形成新的化学键,芳纶分子间氢键缔合程度明显增大,是芳纶1414纤维/1313浆粕复合纸强度提高的主要原因。     

面向3D打印的连续碳纤维上浆工艺及其对复合材料性能的影响

对连续纤维增强热塑性复合材料(CFRTPCs)进行3D打印能够实现无模具快速制造,扩展增材制造的实际应用。为进一步提高3D打印连续碳纤维增强复合材料制件的性能,采用热塑性上浆剂对干碳纤维进行上浆处理,以尼龙6(PA6)为基体打印连续碳纤维增强复合材料,对比了上浆前后碳纤维表面性质及复合材料力学和界面性能。结果表明,上浆后碳纤维表面极性官能团增加,纤维与树脂浸润性改善;纤维表面粗糙度增加,纤维与树脂的机械结合力增强;上浆后碳纤维增强PA6复合材料较原始碳纤维增强PA6复合材料层间剪切强度提高42. 2%,层间结合增强,弯曲强度提高了82%,弯曲模量提高2. 46倍; 3D打印的上浆后碳纤维增强PA6复合材料试样断面上有明显纤维拔出现象,界面性能显著改善。     

造纸专用淀粉在瓦楞原纸中的应用

以玉米淀粉、变性淀粉为原料,添加增强剂、稳定剂复配专用淀粉,从理化指标和糊化特性分析,专用淀粉理化指标无明显变化,糊化性能得到显著提升。选择两种专用淀粉在瓦楞原纸表面施胶中做应用试验,试验证明专用淀粉可降量25%等效替代玉米淀粉。选择效果较好的专用淀粉用于替代木薯淀粉进行表面施胶应用试验,试验证明可等量、等效替代木薯淀粉用于瓦楞原纸中。     

氰乙基淀粉接枝阳离子聚丙烯酰胺树脂的结构与性能

以阳离子淀粉、丙烯腈、丙烯酰胺为主要单体,氧氯化锆(ZrOCl2·8H2O)为交联剂,采用无皂乳液两步聚合法制备了氰乙基淀粉接枝阳离子聚丙烯酰胺树脂(AS-CPAM).用红外光谱(FT-IR)、X射线衍射(XRD)、差示扫描量热分析(DSC)和热重分析(TG)对聚合物结构进行了表征,结果表明,AS-CPAM中各单体单元...     

浆内助剂改善纸模制品表观平滑度的研究

目的研究阳离子淀粉(CS)和阳离子聚丙烯酰胺(CPAM)与加入烷基烯酮二聚体(AKD)乳液浆料的滤水性能及对纸模制品表观平滑度的影响。方法向废旧单面瓦楞纸板浆料中分别加入CS与AKD,CPAM与AKD来制作平板纸模试样。结果相比于只添加AKD的浆料,先加入CS糊化液或CPAM后再加入AKD,浆料的滤水时间和打浆度都有不同程度的降低,且随着CS和CPAM用量的增加,试样的摩擦因数先减小后增加,即试样表面平滑度先提高后降低。结论 HSCS-02型季铵型阳离子玉米淀粉具有较好的助滤性能,能较好地改善纸模制品的表观平滑度,其最佳质量分数为3%;CPAM的助滤性能和对纸模制品表观平滑度的改善作用优于CS,其最佳质量分数为0.06%。     

无机类复合早强剂的制备及其对水稳材料性能的影响

为了研发水泥稳定碎石的无机类复合早强剂,首先将三乙醇胺、硫酸钠分别制成单掺早强剂,以不同比例加入混合料中,测试其1 d龄期下的抗压强度,从两种早强剂中分别选取强度提高最大的4个比例,平行相交混合,配制出16种配比的三乙醇胺-硫酸钠复合早强剂,将不同配比的复合早强剂添入水稳材料中,对比它们1 d的抗压强度,选择出3种表现最好的配比(CN 1.0%+NS 2.0%,CN 0.75%+NS 2.0%,CN 1.0%+NS 1.5%)继续后续实验。其次,研究上述3种配比的早强剂对水泥稳定碎石抗压强度、干缩应变、失水量、温缩应变的影响。结果表明,掺入自配复合早强剂后,对水泥稳定碎石各个龄期的强度均有提高作用,同时降低了混合料的失水量,干缩应变。当早强剂的配比为三乙醇胺1%加硫酸钠2%时,水泥的强度提高最为明显,收缩变形也最好,其在1 d、7 d和28 d龄期下的抗压强度分别提高66%、18%和16%,抗压强度与龄期的关系拟合为Y=A+B×ln(X+C)曲线,干缩应变、失水量也有所下降,温缩性能得到改善。故试验中配制的复合早强剂可以实现早强效果,并可提高水泥稳定碎石的抗收缩能力。     

瓦楞纸箱物理强度测试指标的主因子分析确定法

针对我国对于瓦楞纸箱及其包装件物理强度没有规定严格的检测项目而造成检测项目的随意性,从而不能真实反映瓦楞纸箱及其包装件的运输性能的现状,本文提出了采用主因子分析方法来科学地确定瓦楞纸箱物理强度检测指标,通过实际验证,该方法科学可行.     

GNP-Ni/Cu复合材料的界面调控和强化机理

采用粉末冶金法,通过“湿法混合”、放电等离子烧结和热挤压相结合的三步工艺分别制备了石墨烯纳米片(GNP)增强铜基复合材料(GNP-Cu)和GNP-Ni增强铜基复合材料(GNP-Ni/Cu)。通过物相组成和显微组织表征,并结合致密度、电导率和力学性能测试,结果表明：GNP和Ni的含量(质量分数)分别为0.2%和1.5%的GNP-Ni/Cu复合材料,其显微硬度和屈服强度比纯Cu分别提高了38%和50%、比0.2GNP/Cu复合材料分别提高了14.0%和11.6%。这些结果表明,Ni的添加改善了GNP与Cu的界面结合,使GNP-Ni/Cu复合材料的力学性能显著提高。GNP的载荷传递强化和热失配强化以及Ni的固溶强化,是材料力学性能提高的主要原因。     

Environmental effects on the mechanical and thermomechanical properties of aspen fiber–polypropylene composites

The mechanical properties of newly developed aspen fiber–polypropylene composites (APC) were experimentally explored and numerically predicted at the temperatures and humidity that are typical for domestic housing applications. The mechanical properties of APCs with five different fiber-loadings were evaluated at the room temperature, 4 °C, and 40 °C. Environmental effects on the mechanical properties of APCS were experimentally quantified after conditioning the APCs with two different fiber-loadings in the following temperature and humidity for over 7000 h: (1) hot/dry at 40 °C and 30% relative humidity (RH), (2) hot/wet at 40 °C and 82% RH, (3) cold/dry at 4 °C and 30% RH, and (4) cold/wet at 4 °C and 82% RH. The tensile moduli, flexural moduli, and the flexural strength increased as the woodfiber content increased in the composites. However, the tensile strength decreased as the fiber content increased. The tensile strength was shown to slightly improve with an addition of a coupling agent between the aspen fibers and polypropylene. The simple empirical micromechanics Halpin–Tsai model for randomly distributed short fiber reinforced composites was employed to predict the homogenized elastic moduli of APC, by optimizing the interfacial model parameter. Scanning electron microscopy (SEM) micrographs confirmed that an addition of the adhesion promoter maleated anhydride polypropylene (MAPP) between the aspen fibers and polymeric matrix improved the interfacial bonding.     

基于ANSYS的新型瓦楞纸板结构的有限元分析

借助有限元分析软件ANYSYS10.0,对传统V型瓦楞纸板在静定载荷作用下的力学性能进行了数值模拟,结合U型、UV型瓦楞芯纸结构,设计了O型和不倒翁型两种新型瓦楞芯纸结构,并对所有5种结构纸板的力学性能进行了对比模拟实验。结果表明:V型纸板具有很好的抗压性能,且抗压强度与V形夹角有关;不倒翁型结构瓦楞纸板同时具有良好的抗静压强度和抗冲击性能;各种纸板应力较大区域都集中在各层的粘接处,表现为纸板的应力集中点。     

Effects of long-term aging on moisture sensitivity of foamed WMA mixtures containing moist aggregates

Long-term aging of an asphalt mixture is complicated, but can be simulated in the laboratory. The objective of this study was to investigate the influence of long-term aging on moisture susceptibility of foamed warm mix asphalt (WMA) mixtures containing moist aggregate. Weight loss, indirect tensile strength (ITS) of dry and conditioned specimens, and deformation (flow) were measured for all mixtures. The experimental design included two aggregate moisture contents (0 and ~0.5% by weight of the dry mass of the aggregate); two lime contents (1 and 2% lime by weight of dry aggregate) and one liquid anti-stripping agent (ASA); one foaming WMA additive (Asphamin) and two foaming water contents (2 and 3%); and two aggregate sources. A common long-term aging procedure was used in this study. A total of 64 mixtures were evaluated and 256 specimens were made and tested in this study. The test results indicated that long-term aging improved the moisture resistance of WMA mixtures regardless of the ASA and moisture conditioning. In addition, aggregate source significantly affected the moisture resistance regardless of the foaming technology, ASA, and aggregate moisture content. The mixture with various hydrated lime contents exhibited similar moisture resistance under dry and wet conditions. The liquid ASA used in the WMA mixture showed a weaker resistance to the moisture damage in comparison with hydrated lime.     

Dental application of binary urethane monomer mixtures:strengthened resin matrix

The strengthened resin matrices in six experimental binary visible light-cured (VLC) urethane monomer mixtures were examined in terms of mechanical strength. A 60 wt% bis-GMA/40 wt% binary monomer mixture was used as a control sample. A dry state (1 day in air at 37°C) and a wet state by immersion in distilled water (7 and 30 days at 37°C) were investigated. The compressive strength and diametral tensile strength of urethane monomer samples had values equivalent to, or greater than those of a control sample in the dry state, but had increased values in the wet state. The nano-indentation hardness values in experimental urethane monomer mixtures were greater than that in a control sample in the dry state, showing that immersion in water gave increased strength (maximum increase was about 2.5 times) in six binary urethane monomer mixtures. The compressive strength of the samples in the dry and wet states exhibited linearly increasing elastic modulus values for the resin matrix in the range about 50 to 2600 MPa. The toughened resin matrix had smaller amounts of residual monomer in the urethane monomer mixtures (0.41 to 5.03 wt%) compared with that of the binary 60bis-GMA/40TEGDMA mixture (0.71 to 6.26 wt%). This study has revealed that resin matrices are strengthened by the use of four-functional urethane monomers in experimental binary urethane monomer mixtures.     

硅烷偶联剂对聚乳酸／硅灰石复合材料力学性能的影响

硅烷偶联剂KH550和KH570在乙醇溶剂中以酸水溶液为．催化剂进行水解后时硅灰石粉末进行湿法表面修饰改性。用称重法测定了粉体表面偶联包覆率,以此为指标确定了适宜的水解条件以及反应时间,对偶联效果进行了评价。用溶剂共沉淀法及热压工艺制备了聚乳酸／硅灰石（PDLLA／wollastonite）复合材料。经红外光谱（IR）分析,硅烷偶联剂与硅灰石表面发生化学键合,从而实现表面修饰改性。通过透射电镜（TEM）以及扫描电子显微镜（SEM）分析发现改性硅灰石粒子在有机相中的分散性和稳定性均得到了改善。对改性前后的复合物材料的力学性能进行了测试,结果表明,对硅灰石进行表面改性后,力学性能均得到一定提高,拉伸强度大约提高了5％,弯曲强度大约提高了10％。