通过熔融共混的方法制备了不同配比的聚苯硫醚(PPS)/马来酸酐接枝苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS-g-MAH)共混物,采用热失重方法,分析了SEBS-g-MAH对PPS热稳定性能的影响,并且通过差示扫描量热分析法研究了SEBS-g-MAH对PPS结...通过熔融共混的方法制备了不同配比的聚苯硫醚(PPS)/马来酸酐接枝苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS-g-MAH)共混物,采用热失重方法,分析了SEBS-g-MAH对PPS热稳定性能的影响,并且通过差示扫描量热分析法研究了SEBS-g-MAH对PPS结晶性能的影响,同时研究了PPS/SEBS-g-MAH共混物的力学性能。结果表明,共混物的热稳定性较纯PPS有所下降;PPS结晶峰宽度随SEBS-g-MAH含量的增加先减小后增大,结晶速率和结晶度较纯PPS减小,但对熔点影响较小;SEBS-g-MAH的加入使共混物的缺口冲击强度和断裂伸长率增大,韧性增加。当SEBS-g-MAH含量为40%时,缺口冲击强度为13.1 k J/m2,断裂伸长率为13.7%,但拉伸强度较纯PPS下降,为54.2 MPa。展开更多
对同向啮合双螺杆挤出机混合段选用一定规格的螺杆元件以不同的排序方式组成三种螺杆组合,研究了螺杆结构对聚对苯二甲酸乙二酯(PET)纤维母粒分散性能的影响。在Solid Works 中建立螺杆的物理模型后采用Polyflow 软件对三种螺杆组合进...对同向啮合双螺杆挤出机混合段选用一定规格的螺杆元件以不同的排序方式组成三种螺杆组合,研究了螺杆结构对聚对苯二甲酸乙二酯(PET)纤维母粒分散性能的影响。在Solid Works 中建立螺杆的物理模型后采用Polyflow 软件对三种螺杆组合进行有限元流场模拟分析,运用示踪粒子法统计分析不同螺杆组合的混合效果。以加权平均剪切应力、累积最大剪切速率表征螺杆组合的分散混合能力,以累积停留时间、回流量与回流系数表征螺杆组合的分布混合能力。基于模拟结果,用同向双螺杆挤出机对不同螺杆组合的混合流场进行实验,对经由不同混合流场制备出的PET 母粒的形态进行扫描电镜分析。结果表明,螺纹元件与捏合块元件交错排布的螺杆组合具有更强的分布混合与分散混合能力,更有利于物料的混合。展开更多
A novel particle-size conveying model was established to examine the effects of the dimension relationships of the groove depth and particle size on the solids conveying mechanism of the helically grooved feed section...A novel particle-size conveying model was established to examine the effects of the dimension relationships of the groove depth and particle size on the solids conveying mechanism of the helically grooved feed section. In the model, one or two shear interfaces were proposed based on the dimension relationships of the groove depth and particle size, and the solid-plug embedded in the groove and screw channel were divided into two or three layers by the shear interfaces to consider the solids conveying mechanism of each layer by the boundary condition equation for positive conveying. By the particle-size model, the effects of different dimension relationships on the transformation of solids conveying mechanisms between the friction-drag conveying and the positive conveying were discussed and compared with the on-line measuring experimental data. The results showed that the shear interfaces among the solids existed indeed and the dimension relationships determined the conveying mechanism and the throughput of helically grooved extruders, which was well confirmed by the excellent consistence between the predicted and measured data.展开更多
文摘通过熔融共混的方法制备了不同配比的聚苯硫醚(PPS)/马来酸酐接枝苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS-g-MAH)共混物,采用热失重方法,分析了SEBS-g-MAH对PPS热稳定性能的影响,并且通过差示扫描量热分析法研究了SEBS-g-MAH对PPS结晶性能的影响,同时研究了PPS/SEBS-g-MAH共混物的力学性能。结果表明,共混物的热稳定性较纯PPS有所下降;PPS结晶峰宽度随SEBS-g-MAH含量的增加先减小后增大,结晶速率和结晶度较纯PPS减小,但对熔点影响较小;SEBS-g-MAH的加入使共混物的缺口冲击强度和断裂伸长率增大,韧性增加。当SEBS-g-MAH含量为40%时,缺口冲击强度为13.1 k J/m2,断裂伸长率为13.7%,但拉伸强度较纯PPS下降,为54.2 MPa。
文摘对同向啮合双螺杆挤出机混合段选用一定规格的螺杆元件以不同的排序方式组成三种螺杆组合,研究了螺杆结构对聚对苯二甲酸乙二酯(PET)纤维母粒分散性能的影响。在Solid Works 中建立螺杆的物理模型后采用Polyflow 软件对三种螺杆组合进行有限元流场模拟分析,运用示踪粒子法统计分析不同螺杆组合的混合效果。以加权平均剪切应力、累积最大剪切速率表征螺杆组合的分散混合能力,以累积停留时间、回流量与回流系数表征螺杆组合的分布混合能力。基于模拟结果,用同向双螺杆挤出机对不同螺杆组合的混合流场进行实验,对经由不同混合流场制备出的PET 母粒的形态进行扫描电镜分析。结果表明,螺纹元件与捏合块元件交错排布的螺杆组合具有更强的分布混合与分散混合能力,更有利于物料的混合。
基金Funded by the National Natural Science Foundation of China(No.50873014)
文摘A novel particle-size conveying model was established to examine the effects of the dimension relationships of the groove depth and particle size on the solids conveying mechanism of the helically grooved feed section. In the model, one or two shear interfaces were proposed based on the dimension relationships of the groove depth and particle size, and the solid-plug embedded in the groove and screw channel were divided into two or three layers by the shear interfaces to consider the solids conveying mechanism of each layer by the boundary condition equation for positive conveying. By the particle-size model, the effects of different dimension relationships on the transformation of solids conveying mechanisms between the friction-drag conveying and the positive conveying were discussed and compared with the on-line measuring experimental data. The results showed that the shear interfaces among the solids existed indeed and the dimension relationships determined the conveying mechanism and the throughput of helically grooved extruders, which was well confirmed by the excellent consistence between the predicted and measured data.
