Effect of Structural Units on the Adhesion of Acrylic Copolymers to Fibers for Warp Sizing

Radical copolymerization of acrylic acid (AA) with acrylamide (AM) or acrylamide/acrylonitrlle(AM/AN) was initiated with ammonium persulfate as initiator to produce acrylic copolymers such as bicopolymer poly(AM-co-AA) and tercopolymer poly(AM-co-AN-co-AA) far revealing the effects of the structural unitits of the copolymers on the adhesion of the copolymers to polyester or cotton fibers for warp sizing. The adhesion was evaluated in terms of tensile strength and work-to-break of a roving impregnated with the copolymer solution It was found that the adhesion strongly depended on type and amount of the units incorporated into the copolymeric chains. Whether the fiber is cotton or polyester,the adhesion of the bicopolymer poly(AM-co-AA) is greater than that of polyacrylic acid or polyacyamide. Excessiveiy increasing the amount of AM or AA unit in poly (AM-on-AA) lowers the adhesion. To enhance the adhesion of the bicopolymer,a favorable mole ratio of AM to AA is 70/30. Based on this mole ratio, incorporation of acrylonitrile units into poly (AM-co-AA) to from tcrcopolymer cnhances the adhesion.     

Effect of Electrolyte Impurities within Starch on the Adhesion of Quaternary Ammofiium Starch to Fibers

Influences of some electrolyte impurities within starch and starch cationization on the adhesion of quaternary ammonium cornstarch to cotton and polyester fibers were investigated. The electrolytes considered included NaCI, Na2SO4, NaH2PO4 and Na2HPO4. The adhesion to fibers was evaluated in terms of maximum strength and work-to-break of the roving sized with the starch pastes containing electrolytes. It was found that the cationization showed a positive effect on the adhesion to both fibers whereas the electrolytes gave an adverse effect and reduced the adhesion. The adverse effect depends on the type and amount of electrolytes. The influence of electrolytes on the adhesion can be ranked in a series of NaH2PO4〉 Na2 HPO4〉 Na2SO4 〉 NaCl. The adhesion enhances as the modification extent increases and the electrolyte content decreases. Furthermore, the adverse effect can be compensated by the positive effect of the starch modification even at a low modification extent. If the electrolytes are fully eliminated, the cationic starch can increase the adhesion strength by more than 10% for both fibers.     

Effect of Electrolyte Impurities within Starch on the Adhesion of Quaternary Ammonium Starch to Fibers

Influences of some electrolyte impurities within starch and starch cationization on the adhesion of quaternary ammonium cornstarch to cotton and polyester fibers were investigated.The electrolytes considered included NaCl,Na2SO4,NaH2PO4 and Na2HPO4.The adhesion to fibers was evaluated in terms of maximum strength and work-to-break of the roving sized with the starch pastes containing electrolytes.It was found that the cationization showed a positive effect on the adhesion to both fibers whereas the electrolytes gave an adverse effect and reduced the adhesion.The adverse effect depends on the type and amount of electrolytes.The influence of electrolytes on the adhesion can be ranked in a series of NaH2PO4 > Na2HPO4 > Na2SO4 > NaCl.The adhesion enhances as the modification extent increases and the electrolyte content decreases.Furthermore,the adverse effect can be compensated by the positive effect of the starch modification even at a low modification extent.If the electrolytes are fully eliminated,the cationic starch can increase the adhesion strength by more than 10% for both fibers.     

Effect of Starch Dodecenylsuccinylation on the Adhesion and Film Properties of Dodecenylsuccinylated Starch for Polyester Warp Sizing

A series of dodecenylsuccinylated starches（ DSSs） with different degree of substitution（ DS） were prepared via the esterification of dodencenylsuccinic anhydride with hydrolyzed cornstarch in aqueous dispersion for investigating the influences of starch dodecenylsuccinylation upon the performances such as apparent viscosity and surface tension of starch paste, film behaviors,and adhesion to fibers for warp sizing. It was found that the dodecenylsuccinylation was able to reduce the surface tension of cooked starch paste and enhance the adhesion of starch to polyester fibers. It was also capable of depressing the brittleness of native starch and improving the mechanical behaviours such as breaking elongation and work-to-break of starch film. Initial increase in DS level of dodecenylsuccinylation enhanced these positive effects,while excessively increasing the level resulted in marked reduction in tensile strength of starch film and significant decrement in reaction efficiency. X-ray diffraction patterns of starch films showed the dodecenylsuccinates derivatized onto the backbones of starch depressed the degree of crystallinity of starch film. Based on the paste behaviors, adhesion, and film properties, the dodecenylsuccinylation level is recommended in a range of 0. 015-0. 025 for sizing polyester warps.     

油田采出水中微生物对部分水解聚丙烯酰胺溶液黏度的影响初探

在实验室条件下,研究了油田采出水中常见微生物类群(腐生菌、硫酸盐还原菌、铁细菌、反硝化细菌)对不同分子质量部分水解聚丙烯酰胺(HPAM)溶液黏度的影响.结果表明:腐生菌及反硝化细菌对聚合物黏度的影响很小;硫酸盐还原菌直接利用大分子聚合物的能力十分有限,但其代谢产物可以显著降低聚合物黏度;铁细菌可以利用聚合物生长,是破坏聚合物黏度的主要微生物类群.     

木质素对聚丙烯酰胺降粘性能评价

聚驱过程中存在聚合物黏度过高的问题而影响了原油采收率,因此提出降低聚合物黏度的问题。木质素作为一种廉价的表面活性剂用于三次采油,在油田有广泛的应用前景。对于同浓度同体积的HPAM,加入木质素的质量越多,黏度下降速度越快。木质素与多种降黏剂的复配降黏效果实验中,降黏效果的比较为:HCl>NaS2O8>NaClO。     

乙酰化变性对氧化淀粉与PVA浆液混溶性的影响

以初显分离时间和沉降率为量化指标,定量研究了淀粉氧化后的乙酰化变性对它与１７９９ 、１７８８ 和０５８８ 三种聚乙烯醇混溶性的影响。实验结果表明,淀粉的氧化程度和乙酰化变性、ＰＶＡ分子结构以及混合浆组分都会对其混溶性产生一定的影响。淀粉乙酰化变性和ＰＶＡ 分子结构对淀粉与ＰＶＡ 混溶性的影响是有限的,远不如氧化深度的影响程度大。此外,本文也为进一步提高浆纱质量、降低浆料成本提供了一定的参考依据。     

完全可分的三元系TS(v,5)的支撑数集合

主要解决了完全可分的三元系TS(v,5)的支撑数集合,其中正整数v≡1,3(mod 6).     

Effects of Alkali Treatment on the Structure of Tencel Fibers

Alkali treatment can change the structures and properties of cellulosic fibers. The aim of this work was to study the mechanism of structure changes of Tencel fibers treated with different alkali concentration and two treatment methods. Raman spectrum showed that the molecular conformation of Tencel fibers remained unchanged. XRD (X-ray diffraction) indicated that the crystallinty of Tencel fibers in original length increased while that of fibers in relaxation condition remained unchanged. The average crystallite size increased and the orientation index decreased. The quasi-crystallite disassociation and recrystallization in the quasi-crystalline phase during the process of alkali treatment lead to the changes of the crystallinity and the orientation index of Tencel fibers.     

微观结构尺寸对钢疲劳性能的影响

研究了超高强度钢 30 Cr Mn Si Ni2 A的微观结构尺寸对其疲劳性能的影响 .试验结果表明 :在淬火 低温回火状态下 ,这种钢的旋转弯曲疲劳极限σ- 1随其微观结构尺寸(原奥氏体晶粒或马氏体束径尺寸 )的减小而提高 ,且有关系式σ- 1=σ0 kd- 1/ 2 .这样 ,就可以通过测量钢的微观结构尺寸来估算其疲劳性能     

Study on the Preparation of Allyl-modified Starch in Isopropyl/Water Medium for Warp Sizing

A new method for the pretreatment of starch by etherification was developed to eliminate the problems of lower grafting efficiency associated with the preparation of starch graft copolymers as warp sizing agents. The etherification of starch with allyl chloride was investigated in order to effectively enhance the reaction efficiency. The tecimological variables of the reaction considered for evaluating the etherification included sodium hydroxide amount, water content in water-isopropyl alcohol medium, allyl chloride concentration, reaction temperature and reaction time. The experimental result demonstrated that the variables considered showed evident effect on the reaction efficiency. For the etherification, a condition of 20% for the water content, 1.5：1 for the molar ratio of sodium hydroxide to allyl chloride, and at 30℃ under 24 h reaction is sufficient to retain the reaction efficiency above 50%. Furthermore, a contrast test demonstrated that the graft efficiency can be increased with the etherification pretreatment.     

傅立叶变换红外显微光谱技术及其在高性能纤维研究中的应用

介绍了傅立叶变换红外显微光谱技术的历史、现状及其主要分析技术。通过具体的实例，分析了该技术在高性能纤维研究中的应用情况。     

醋酸纤维的改性研究

醋酸长丝是优良的纺织原料，既有纤维素纤维的服用舒适性，也有合成纤维的尺寸稳定性。在美国、日本等发达国家，目前醋酸纤维在纺织领域的应用和发展已比较成熟。综述了醋酸纤维的改性研究现状，重点讨论了差别化醋酸纤维的开发和改善醋酸纤维强力的研究。认为国内有必要对醋酸纤维的结构、特性进行研究，加深对该纤维的认识和理解，并在此基础上开发、推广醋酸纤维在我国纺织领域的应用，从而解决该纤维长期进口的问题。     

涤纶织物与橡胶的粘合研究

通过浸渍改性环氧树脂（ＳＪＲ－２）和预缩合间苯二酚甲醛树脂（ＳＪＲ－１）的水溶液，然后半固化，实现了涤纶织物的表面粘合活化，接着浸由ＳＪＲ－１配制的间苯二酚甲醛胶乳（ＲＦＬ）浸渍液，即可获得与ＮＲ、ＣＲ、ＨＮＢＲ、ＮＢＲ及氯醇胶（ＣＨＲ）等胶料优良的粘合性能．     

硅胶的孔径结构对脱附活化能的影响

该文为研究硅胶孔结构对水蒸气吸附速率／脱附活化能的影响，在吸附水蒸气动力学实验中采用了间歇式吸附方法，用程序升温脱附技术测定了水在硅胶上的程序升温脱附（TPD）曲线并估算了水的脱附活化能。结果表明：A型、B型和C型硅胶的平均孔径分别为2nm、5．28nm和10．65nm。在10％～45％低湿范围内，硅胶的平均孔径越大，其吸附初始阶段的吸附速率越快，平衡吸湿量越小；高湿度条件下，硅胶的平均孔径和孔容越大，其吸附初始阶段的吸附速率越慢，平衡吸湿量越大。水分子在A型、B型和C型硅胶上的脱附活化能分别为35．54kJ／mol、31．41kJ／mol和26．16kJ/mol，说明水分子在硅胶上的脱附活化能随着硅胶的孔径增加而明显减小。与微孔硅胶相比．在中高湿度下中孔硅胶有较大的平衡吸附量和较低的脱附活化能。     

高梁叶中的多核纤维和分隔纤维

高粱(Sorghum vulgares Pers.)叶中的纤维在发育过程中出现多个细胞核现象,细胞核的数目1～7个,一般为1～3个。这种多核纤维的细胞核形状也不同,有圆球形、纺锤形和伸长的线形。纤维中出现的多核现象是由于纤维在早期发育过程中连续进行核分裂形成的,或者是发育的分隔纤维在形成横隔前出现短暂的多核时期。除这种多核纤维外,高粱叶中还青许多具有生活原生质体的分隔纤维。     

Effects of Electrochemical Treatment on the Superficial Properties of Rayon-based Carbon Fibers

The development of surface acidity on rayon-based carbon fibers during mild electrochemical treatment was investigated. Conductimetric titration was the primary method used to investigate the functionalities on the carbon fiber surface. The acidity on the surface of the untreated carbon fiber was very low, while for the treated fibers, the acidity increased significantly. Moreover, with the treatment extent proceeded, the acidity on the fiber surface also increased. SEM analysis shows electrochemical treatment under intense treatment degree caused considerable etch on the fiber surface. Cavities and grooves can be observed on the surface via the SEM microphotograph. While in a more mild treatment, electrochemical treatment didn't cause great etch on the surface of the fiber.     

水性聚氨酯粒径和黏度性能的研究

合成了单官能团小分子物质封端的软硬段皆含羧基的脂环族水性聚氨酯(PU)分散体，研究了羧基含量、pH值、c(NCO)／c(OH)比值、反离子种类和固含量对PU的粒径、黏度和特性黏度的影响。同时，比较了黏度与特性黏度之间的区别与联系。实验结果表明：随pH值的增大，PU分散液体系粒子粒径减小，临界值为8．0；随羧基含量的升高，PU分散液体系粒子粒径减小，临界值(质量分数)为4．05％，而PU分散液体系黏度与特性黏度均增加，此后在有限范围内波动变化，这表明PU分散液体系宏观与微观性能变化趋于一致；随c(NCO)／c(OH)比值升高，PU体系黏度逐渐增高，特性黏度与相对分子质量迅速下降。     

聚(丙烯酰胺/丙烯酰氧乙基二甲基苄基氯化铵)的合成研究

以丙烯酰胺(AM)和丙烯酰氧乙基二甲基苄基氯化铵(DBC)为共聚单体,采用水溶液聚合法制备了阳离子型聚丙烯酰胺,研究了单体配比、引发剂、反应温度以及反应时间对产物的影响,并用红外光谱和核磁氢谱对产物结构进行了鉴定.实验发现一定范围内减少引发剂用量、降低反应温度均能提高共聚物分子量,引发剂滴加完毕之后40min时产物黏度最高.     

Starch Modifications to Improve the Paste Stabilities Both in Phase and Viscosity for Warp Sizing

Introduction Starchandpolyvinylalcohol(PVA)arecommonly usedtogetherinablendedpasteforsizingvarious synthetic/celluloseblendspunyarns.Tousestarch satisfactorily,thehotpasteofstarchmusthavesufficient viscositystabilitysinceunstablestarchpasteinviscosity tendstobecomethinning,thatis,theviscositydecreases withdelayoftime.Variationinpasteviscosityfluctuates sizeadd on,whichisseriouslyharmfultothequalitiesof sizedyarns.Tocompensateforthedefect,cross linking treatmentsareoftenappliedtostarchsizesto…