Effects of Coagulation Conditions on Tensile Properties of Regenerated Cellulose Fibers

The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers hav...     

纺速对PEIT卷绕丝超分子结构及力学性能的影响

借助由X射线衍射法，密度法，DSC法测定的结晶度和沸水收缩率，自然拉伸比，声速取向因子等指标来描述纺丝速度在2400－5000m/min范围内变化的PEIT卷绕丝的超分子结构。在实验的纺速范围内，PEIT卷绕丝的结晶度随纺速增加的过程中有突变现象，这主要是因为分子取向诱导所致。最后，就不同纺速下PEIT初生丝的力学性能特征值进行了对比。     

无皂种子乳液法制备复合微球

介绍了无皂种子乳液制备复合微球的方法，重点阐述了加料方式，单体亲水性、引发剂，交联剂及交联度，壳单体与种子乳胶间相容性等因素对复合微球形态的影响。     

纤维素在氢氧化钠／硫膨尿素／水溶液中的溶解和溶液特性

使用氢氧化钠／硫脲／尿素／水溶液作为纤维素的复合溶剂,研究了纤维素在其中的溶解行为和溶液性质,发现该体系在-10℃条件下能快速溶解纤维素,其溶解是一个没有衍生物生成的直接过程,该纤维素溶液在过高温度下易凝胶化．     

在硫氰酸钠浓水溶液中丙烯腈-酪素接枝共聚的研究

采用傅利叶红外光谱表征了在硫氰酸钠(NaSCN)浓水溶液中丙烯腈(AN)、酪素(Casein)均相接枝共聚制得的接枝共聚主产物为AN—g—Casein接枝共聚物,研究了反应时间、单体质量分数、引发剂质量分数、反应温度对接枝共聚的影响,讨论了反应前酪素的溶解条件。     

Study on Shrinkage of PEIT Fiber and Latent - crimp of PEIT/PET Conjugate Fiber

The shrinkage behavior of copoiyester fibers (PEIT) and the ' latent - crimp behavior of side - by - side PET/ PEIT composite fibers have been studied. It is shown that the shrinkage rate, the crimp ratio and the crimp rigidity of these fibers increase with the increasing isoph-thalate content of PEIT and the treatment temperature. The shrinkage in boiling water of the cold - drawn PEIT - A2 fiber appears to be higher than that of PEIT - A3. The shrinkage in dry air of the cold - drawn PEIT - A2 fiber is also higher than that of PEIT at temperature of 393 K or 413K, but lower at 453K. The crimp rigidity of the PET/PEIT - A: conjugate fiber appears to be obviously higher than that of the PET/PEIT - A, conjugate fiber. The mechanism of the shrinkage behavior related these fibers are discussed in detail.     

Characterizations of Phosphorus - containing Flame - retardant Poly (Ethylene Terephthalate) Copolyester

Copolyesters of phosphorus - containing flame - retardant poly(Ethylene Terephthalate) (PET) have been prepared and characterized with the objection of producing an effective, environmentally friendly, nonfugitive alternatives to halogen flame retardant system for practical application. With means of NMR, DSC, DTA/TGA, SEM and LOI, structure, thermal property and flam-mability are investigated which reveal that the flame -retardant PET when copolymerized with 2 - carboxyethyl (phenylphosphinic) acid (CEPP) confers excellent fire retardancy with LOI > 28, broader thermal degradation temperature and increased char formation.     

聚乙二醇——聚对苯二甲酸乙二酯嵌段共聚物的多重熔融和结构重建

本文应用差示扫描量热法(DSC)、广角 X 光衍射(WAXD)、偏光显微镜(PLM)、小角激光光散射(SALS)等方法,对聚乙二醇—聚对苯二甲酸乙二酯(PEG—PET)嵌段共聚物的结晶和熔融行为进行了研究。结果显示,在 DSC 扫描过程中,PEG—PET 经历了多重熔融与结构再组合的过程.当PET 链段结晶时,PEG 链段被挤出 PET 折叠链的表面,并不生成共晶.在 PET 的折叠链的弯折处,由于 PEG 链段的内增塑作用.使折叠链内应力降低.堆砌紧密,得到了 PET 在同等条件下所不能得到的完整的晶面衍射.嵌段共聚物在200℃淬火2h,PEG 链段无法挤出球晶的表面,从而形成了混品.且球晶的光轴方向发生偏转.     

AN-g-casein浓溶液在毛细管流动中的末端校正

采用气压式毛细管流变仪，测定了实验室自制丙烯腈－酷素接枝共聚物（ＡＮ－ｇ－ｃａｓｅｉｎ）浓溶液的流变性能。实验结果发现：ＡＮ－ｇ－ｃａｓｅｉｎ浓溶液属切力变稀型非牛顿流体；在实验范围内，毛细管流动中的末端校正系数ｅ随切变速率的提高而增大，当切变速率较高时，ＡＮ－ｇ－ｃａｓｅｉｎ大分子在浓溶液中形成了束状物，拉伸变表受到了限制，ｅ值上升趋于极限；当切变速率较高，毛细管长径比较小时，真实剪切应力仅占表     

聚(对苯二甲酸,间苯二甲酸-5-磺酸钠-乙二醇,2-甲基1,3-丙二醇)的结构性能

在聚对苯二甲酸乙二酯(PET)聚合中添加间苯二甲酸-5-磺酸钠(SIPE)和2-甲基-1,3-丙二醇(MPD),成功制备了聚(对苯二甲酸,间苯二甲酸-5-磺酸钠-乙二醇,2-甲基1,3-丙二醇)(MCDP).采用核磁共振(NMR)、热失重分析(TGA)、差示扫描量热法(DSC)、广角X-先衍射(WAXD)、偏光显微镜(POM)等表征分析了MCDP的结构性能.结果发现MCDP中所测MPD的摩尔分数较投料比例略高;MCDP的热稳定性略有下降;随MPD摩尔分数的增加,MCDP的结晶程度及速率降低,但球晶的形态及生长机理无显著影响.