采用差示扫描量热仪、偏光显微镜和X射线衍射仪等研究了透明成核剂和透明聚丙烯的结晶行为和结晶形态。结果表明:山梨醇类透明成核剂第二次升温比第一次升温熔融温度下降10~50℃,熔融焓下降50%~90%;纯聚丙烯结晶温度约为110℃,熔融温度约为152℃,球晶尺寸约50μm,晶型为α晶;加入透明成核剂后,聚丙烯的结晶温度升高约10℃,熔融温度升高约3℃,晶粒尺寸约1μm,晶型仍为α晶。

The crystallization behavior and morphology of transparent nucleating agents and transparent polypropylenes were studied by differential scanning calorimetry (DSC), polarized light microscopy (PLM) and X-ray diffraction (XRD). The results indicate that the melting temperature of sorbitol nucleating agents decreases by 10-50 ℃ at the second heating up with the melting enthalpy decreasing by 50%-90% in comparison with those at the first heating up. The crystallization temperature, melting temperature of neat polypropylene is about 110, 152 ℃, respectively and the crystal structure is α form with spherulite size of approximately 50 μm. After adding the transparent nucleating agent, the crystallization temperature, melting temperature of polypropylene increases about 10, 3 ℃, respectively and the crystal structure is still α form with grain size deceasing to about 1 μm.

利用正硅酸乙酯水解法制备硅溶胶,在熔融石英粉体表面进行同质溶胶包覆,经过洗涤、干燥、煅烧处理后得到包覆粉体。以原始粉和包覆粉为原料,在不同烧结温度下制备了熔融石英陶瓷,研究了包覆前后粉体的烧结性能以及包覆对陶瓷烧结体析晶行为和力学性能的影响。结果表明:在熔融石英粉体表面包覆一层同质溶胶后,粉体性能明显优于原始粉体。与原始粉体烧结体相比,相同烧结温度下包覆粉体烧结体体积密度和抗弯强度明显提高,显气孔率降低,溶胶包覆没有影响熔融石英陶瓷的析晶行为。1 200℃烧结的溶胶包覆粉体样品综合性能最佳,体积密度达到1.89 g/cm3,抗弯强度最大值为30.2 MPa,没有发生析晶现象。

A silica sol was firstly prepared via the hydrolysis of TEOS, and then the surface of fused silica particles was coated by a homogeneous sol layer. The coated particles were obtained after washing, drying and calcination treatment. The fused silica ceramic was prepared with the original and coated particles at different sintering temperatures. The sintering properties of the original and coated particles were investigated. The effect of sol-coating on the crystallization behavior and bending strength of the ceramic sin-tered samples was also analyzed. The results show that the property of the fused silica particles coated with homogeneous sol layer is superior to that of original particles. Compared to the sintered sample using original particles as a raw material, the sample with coated particles sintered shows a higher volume density, a greater bending strength and a lower apparent porosity rate. The crystalliza-tion behavior of the fused silica ceramic is not affected by the sol lay

利用差示扫描量热法研究尼龙（PA）11／SiC复合材料在不同结晶温度的等温结晶及熔融行为，采用Avrami方程研究复合材料的等温结晶动力学，用Hoffman．Weeks理论研究复合材料的平衡熔点。结果表明，Avrami方程能够较好地描述PA11／SiC复合材料的等温结晶动力学；在复合材料中，SiC起到了异相成核作用，提高了等温结晶速率，随着结晶温度的升高，结晶速率逐渐降低；PA11／SiC复合材料等温结晶后的熔融曲线均为双重熔融峰，当结晶温度足够高时，晶体趋于完美，只存在一个熔融峰；与纯PA11相比，PA11／SiC复合材料有较低的平衡熔点。

Isothermal crystallization and melting behaviors of nylon(PA)11/SiC composites in different crystallization temperature were investigated by differential scanning calorimetry. The isothermal crystallization kinetics of the composites were investigated by Avrami equation. The equilibrium melting point of the composites were studied by Hoffman-Weeks theory. The experimental results show that the Avrami equation can well describe the isothermal crystallization kinetics of PA11/SiC composites. SiC plays a role of heterogeneous nucleation in composites,improved isothermal crystallization rate. With the increase of crystallization temperature,crystallization rates gradually reduce. Isothermal melting curve of PA11/SiC composites are double melting peaks. As the crystallization temperature increases to a high enough temperature,the crystal tends to be perfect,which has only a melting peak. Compared with pure PA11,PA11/SiC composites have a relatively low melting point.

通过添加聚乙烯醇( PVA)、二氧化硅( SiO2)到木薯淀粉中,采用熔融密炼法制备热塑性木薯淀粉( TPS)/PVA/SiO2共混材料,研究共混材料的吸水性、生物降解与熔融行为。研究结果表明：随着SiO2用量的增加, TPS/PVA/SiO2共混体系的吸水率增加, TPS/PVA (1799)/SiO2共混材料的吸水率高于 TPS/PVA (1788)/SiO2共混物。表面改性后SiO2的TPS/PVA/SiO2共混物的吸水率低于未改性SiO2。随着SiO2用量的增加,TPS/PVA/SiO2共混物的生物降解降低,共混物的熔融峰增高,而熔融焓降低。

The thermoplastic tapioca starch( TPS)/PVA/SiO2 blends were prepared through melt mixing meth-od,by adding polyvinyl alcohol(PVA),silica(SiO2)into cassava starch,and the water absorption,biodegradation, and melting behavior of the blends were investigated. The research results indicated that with the increase of SiO2 content,the water absorption of TPS/PVA/SiO2 blends increased,and the water absorption of TPS/PVA(1799)/SiO2 blends was higher than that of TPS/PVA(1788)/SiO2 blends. The water absorption of TPS/PVA/SiO2 blends with SiO2 surface treated was lower than that of the untreated SiO2. With the increase of the SiO2 content,the bio-degradation of TPS/PVA/SiO2 blends decreased,the melting peak of the blends increased,however the melting en-thalpy decreased.

采用熔融纺丝法制备了高密度聚乙烯(HDPE)/埃洛石纳米管(HNTs)复合纤维。利用差示扫描量热法研究了HNTs对HDPE基体非等温结晶行为的影响,利用二维广角X射线衍射研究了熔融纺丝过程中的卷曲速度和加入HNTs对HDPE/HNTs复合纤维中HDPE基体晶片扭曲行为的影响。结果表明:HNTs在HDPE中起成核剂的作用,提高了HDPE基体的起始结晶温度和最大结晶温度,缩短了半结晶时间。随着卷曲速度的升高和HNTs含量的增加,HDPE基体晶片扭曲程度逐渐降低。

High density polyethylene (HDPE)/halloysite nanotubes (HNTs) composite fibers were fabricated by melt spinning method. The effect of HNTs on nonisothermal crystallization behavior of HDPE was studied by differential scanning calorimetry (DSC). The effect of take-up velocity and adding HNTs on the lamellar twisting of HDPE in melt spun HDPE/HNTs composite fibers during melt spinning was researched by two-dimension wide angle X-ray diffraction (2D-WAXD). The results show that HNTs can serve as a nucleating agent, shifting on-set crystallization temperature and maximum crystallization temperature to a higher end and shortening half crystallization time during nonisothermal crystallization. Lamellar twisting of HDPE is restricted with the increase in the take-up velocity and the mass percentage of HNTs.