Orientation and Crystallinity Measurements in Injection Moulded Products

Summary Orientation and crystallinity of isotactic polypropylene moulded products have been investigated by means of infrared microscopy. The experimental techniques are described elsewhere [ 1-31]. The previous application to film casting products and the application in this work to injection-moulded products confirms their usefulness in polymer science. Orientation and crystallinity distributions obtained for different samples are reported and briefly discussed.     

Control of Crystallinity of Hydrated Products in a Calcium Phosphate Cement

A novel calcium phosphate cement (CPC) was prepared by dry-mechanochemical rout in this work. With the different crystallinity, the CPC showed the different degradation ratio after setting. The degradation ratio of CPC was characterized by the calcium ion-dissolving ratio in deionized water after different soaking time. With the increment of crystallinity, the setting times of CPC were prolonged, and the different mechanical property of CPC were obtained. This novel CPC was supposed to match the new bone ingrowth in vivo and have the potential application in orthopedic surgery for filling non-load-bearing bone defects.     

聚丙烯在生产中采用双向拉伸法对薄膜性能的影响

分析了BOPP薄膜生产过程中的取向和结晶对薄膜机械力学性能和光学性能的影响,实际生产中生产工艺应该根据PP的热力学特性相应调整,以制造出双向取向度高,同时结晶微细、均匀的高性能优质BOPP薄膜。     

PUU—RRIM制品中玻璃纤维的取向

通过扫描电子显微镜观察了聚氨酯脲（ＰＵＵ）体系增强反应注射成型（ＲＲＩＭ）制品中玻璃纤维的取向和分布规律。发现在流动横截面上,玻璃纤维非均一分布,其中规则取向区域与杂乱积区域交替存在,呈现多层分布结构,建立了充模过程流体流动方程,应用速度分布方程,对玻璃纤维多层分布结构进行了理论分析。     

关于水系流延过程中膜带干燥的若干问题研究

水基流延成型的膜带在干燥技术的许多方面存在着“知其然而不知其所以然”,其干燥过程在固体介质中同时发生热量、质量和动量的传递,用数学对其进行描述存在着相当的困难性和无效性.可以将流延膜的干燥过程分为恒定速率阶段和蒸发速率下降两个阶段.过去由于实验技术条件的限制使人们对一些干燥机理没有充分的认识,就是研究较多的干燥动力学,也存在禁地和误区.由于干燥机理复杂,目前研究得不够充分,关于干燥的动力学数据多取自试验测定值.通过结构与性能关联的研究可拓展人们对于燥过程的认识:通过电子显微镜对膜带的表征,可深入研究其显微结构及湿组份在膜带内的运动机理;通过热重分析技术将膜带的湿度变化与其温度变化相关联,可为设计干燥工艺提供合理的依据;通过固相核磁共振技术,测量湿组份中水分子层的质子自旋松弛时间,可用来半定量计算膜带中的可除去结合水和自由水及不可除去结合水的比例.     

胶原蛋白流延薄膜的研制

采用流延成型法将胶原蛋白水溶液进行流延、凝固、后处理、干燥等工序制备出了胶原蛋白薄膜;测试了胶原蛋白薄膜的红外光谱和拉伸强度、断裂强度、断裂伸长率等力学性能;讨论了后处理液质量浓度、后处理时间对胶原蛋白薄膜力学性能的影响.结果表明:胶原蛋白分子间发生了交联反应;随着后处理时间延长和后处理液质量浓度增大,胶原蛋白薄膜的拉伸强度、断裂强度和断裂伸长率等力学性能得到改善和提高;对经过后处理的胶原蛋白薄膜进行浸水后,其耐水性有明显提高.红外光谱说明胶原蛋白分子间发生了交联.     

聚丙烯流延薄膜现状及发展趋势(续)

介绍了聚丙烯流延薄膜在国内外的生产现状和发展趋势，着重评定述了挤出流延设备的结构。聚丙烯专用料的性能，流延聚丙烯薄膜的品种，以及流延薄膜的应用。     

聚丙烯流延薄膜现状及发展趋势

介绍了聚丙烯流延薄膜在国内外的生产现状和发展趋势。着重评述了挤出流延设备的结构，聚丙烯专用料的性能，流延聚丙烯薄膜的品种，以及流延薄膜的应用。     

Alumina Carbon Refractory Products for Continuous Casting

YB/T 007-2003 1 ScopeThis standard specifies the classification,technical requirements,test methods,inspection rules,packing,marking,transportation,storage and quality certificate of alumina carbon refractory products for continuous casting. This standard is applicable to the alumina carbon(composite zirconia carbon,magnesia carbon)refractory products for iron and steel continuous casting.     

Determination of Texture from Individual Grain Orientation Measurements

We present a technique for determining the texture of a polycrystalline material based on the measurement of the orientation of a number of individual grains. We assumed that the sample has fiber (i.e., axisymmetric) texture and that the texture can be characterized by a function (the March-Dollase function) with a single parameter. We simulated a large number, N , of orientation data sets, using the March-Dollase function for a total of five different texture parameters, r ^init. Using the maximum-likelihood method, we solved for the texture parameter, r ´, that best fits each simulated data set in order to determine the distribution of r ´ and evaluate the precision and accuracy with which r ´ can be determined. The 90% confidence limits of the ratio r ´/ r ^init vary as N ^-1/2 but were independent of r ^init. Using the texture of slightly textured Al₂O₃ as determined by X-ray diffraction, we calculated the 90% confidence limits for measurements of 131 grains. The orientations of 131 grains in textured Al₂O₃ were measured by electron backscatter diffraction, and the texture determined from those measurements lay within these 90% confidence limits.     

SiC Products Formed by Slip Casting Method

The paper presents results of research designed to obtain a dense silicon carbide materials shaped by slip casting of aqueous suspensions. Aluminum oxide and yttrium oxide were used as sintering additives in a weight ratio of 3:2 in an amount of 10% by mass relative to the dry weight. The slip was electrostatically stabilized by adjusting pH. Measurement of the zeta potential as a function of pH and viscosity tests as a function of pH and volume fraction of the solid phase allowed for making selection of the suspension parameters, such as the solid volume loading (30%) and pH of ~ 8.5. Results of these investigations confirmed that it is possible to produce pseudoplastic slips suitable for slip casting. The increase in the strength of green bodies, allowing for their green processing, was obtained by addition of a commercial acrylic binder. SiC casts were sintered at 2050°C, which led to materials with high density and fine, homogeneous microstructure. The fracture toughness test revealed a positive effect of the sintering additives on K_Ic of the material, increasing its value to approximately 5 MPa·m^1/2.     

流延法制备8YSZ薄膜

采用非水基流延法制备了8mol%氧化钇稳定氧化锆薄膜,研究了球磨时间、固含量、有机添加剂含量及除泡工艺对8YSZ浆料流变性能的影响,通过SEM表征烧结体表面形貌,用电化学阻抗仪对烧结体进行电导率测试。结果表明:分散剂用量1.25wt%,球磨时间15h,浆料的粘度最小,分散效果最好;增塑剂与粘结剂比例为0.7,粘结剂加入量6.5～8.5wt%,二次球磨后,真空除泡可获得适合流延的浆料;生坯1450℃烧结4h,烧结体晶界清晰、致密度较好;烧结体在300～800℃随温度的升高电导率逐渐增大,在800℃时离子电导率达0.046S/cm。     

BC107抗菌粉体在PE流延打孔膜中的应用

先将BC107抗菌粉体制成BCM—E02A抗菌母料,再加入原材料混合均匀,然后经过流延成型、打孔制备出抗菌流延打孔膜。当BCM—E02A抗菌母料的用量为4％时,抗菌流延打孔膜具有高效广谱的抗菌性能,光老化性能优越．毒理试验符合要求。     

氮化铝薄膜光学常数和结合力测试分析

用直流磁控溅射方法在硅衬底上制备氮化铝薄膜。X射线衍射仪和X射线光电子能谱仪分析了薄膜的结构和成分;椭圆偏振仪测量并拟合获得AlN薄膜在250～1000nm波长范围内的折射率和消光系数曲线;利用大荷载划痕仪的声发射谱检测方法并结合不同压力下的划痕显微形貌观察得到薄膜临界载荷(结合力)L为29.45N。     

双向拉伸聚丙烯薄膜晶点、白点、鱼眼的研究

双向拉伸聚丙烯薄膜(BOPP薄膜)具有良好的光学性能、阻隔空气及优异的机械性能,是一种性能优良的高透明包装材料,被誉为"包装皇后",用途广泛。要保证BOPP薄膜的正常使用,需要严格控制薄膜的物理机械性能和外观缺陷,着重探讨了BOPP薄膜的晶点、白点、鱼眼的产生及控制措施。     

谈日用瓷注浆浸釉产品釉泡的成因及其消除办法

陶瓷产品起泡原因比较复杂,贯穿整个生产工艺过程。本文对日用瓷注浆浸釉产品的釉泡成因进行了探讨,并提出一些解决问题的方法。     

再生纤维素表面氨基聚硅氧烷的膜形貌及定向排列方式

以再生纤维作基质,在其表面组装了N-环己基-γ-氨丙基聚二甲基硅氧烷(ASO-702).分别用X-射线光电子能谱(XPS)、原子力显微镜(AFM)以及接触角测定仪对处理后的再生纤维素表面的形貌进行了观察和表征.结果表明,在再生纤维素表面,氨基聚硅氧烷ASO-702能形成均匀的疏水膜,该膜能有效降低再生纤维基质表面的粗糙度;在处理后的再生纤维表层确有聚硅氧烷膜存在,且该膜疏水.接触角达到91.5°.从而进一步证明了氨基聚硅氧烷在纤维表面的定向排列成膜方式为:硅甲基朝外、Si-O偶极键及阳离子化氨基指向纤维表面.     

双向拉伸聚丙烯薄膜铸片成型水槽水循环系统的设计

冷辊水槽铸片成型法是生产双向拉伸聚丙烯(BOPP)薄膜常用的方法,通过优化升级改进了原有结构冷却效果不佳,调节不便等缺陷,使系统结构稳定可靠、操作维护便捷,铸片片材能够快速冷却定型,有效提高了薄膜的生产效率。     

PPC/PBAT薄膜制品性能研究

利用吹膜挤出机组制备了聚碳酸亚丙酯树脂(PPC)与聚己二酸/对苯二甲酸丁二酯(PBAT)共混薄膜,研究了扩链剂和开口剂对PPC/PBAT熔体流动性和力学性能的影响。结果表明:随着扩链剂用量的增加,PPC/PBAT共混物的熔体流动速率呈下降趋势;扩链剂的加入使PPC/PBAT薄膜的纵向和横向拉伸强度明显提高,纵向和横向撕裂强度也较未加扩链剂时有较大提高;开口剂的加入不仅使薄膜容易开口,而且提高了吹膜过程的稳定性及薄膜的质量。     

Crystallinity in EPDM terpolymers

The crystallinity of a series of ‘medium-high’ green strength EPDM terpolymers has been examined by X-ray diffraction and thermal analysis. It has been found that the crystallinity of such materials can vary from 0.20% as measured by thermal analysis, and depends on the E:P ratio in the polymer. It is also suggested that it depends on the distribution of E and P units. An explanation for the differing results obtained by thermal analysis and X-ray diffraction has been proposed. The time taken to achieve maximum crystallinity varied for the series of polymers examined, and the improvement of crystallites continued over extensive periods of time. The final level of crystallinity in the polymers and the rate of changes occurring was temperature dependent. For one sampel (‘Nordel’ 1560) it was shown that crystallinity affected mechanical properties.