共查询到19条相似文献,搜索用时 140 毫秒
1.
2.
3.
4.
5.
微孔发泡塑料挤出过程中各种影响因素的研究 总被引:4,自引:0,他引:4
微孔物理发泡因其制品的诸多优点而越来越受到人们的重视,目前人们已逐渐开始将研究重点从发泡成核机理研究转到加工过程中诸多因素的研究,以求更好的实现对泡孔尺寸,分布及密度的控制,针对微孔塑料挤出的全过程,对影响气泡成核,成长及泡孔密度的诸多因素如预定型压力,熔体温度,粘度,气泡界面张力,定型卷取速度,冷却水温等进行了全面分析,从而使微孔塑料的生产更趋合理化。 相似文献
6.
7.
本文采用高温拉伸试验方法,系统地的 试验条件及材料组成的RPVC挤出低发泡工艺中PVC熔体延伸形变性能的影响。结果表明:在23 ̄192℃范围内,随着温度的升高,PVC材料的伸强度降低,断裂伸长率呈凸凹形变化。 相似文献
8.
9.
10.
11.
苯乙烯类热塑性弹性体对IR/CR的增容作用 总被引:1,自引:0,他引:1
采用相差显微镜及Moony-Rivlin方程中的2C1和2C2等方法,研究了少量SIS,SBS,α-甲基苯乙烯和丁二烯的三嵌段共聚物(MSBMS)对IR/CR共混物相态结构、交联行为和力学性能的影响。结果表明,加入SIS,SBS,MSBMS厅明显降低分散相尺寸,使体系分布均匀,提高了硫化胶的交联密度和拉伸强度。降低节体系煌内部损耗。对IR/CR共混物的增容效果,以SIS为最好,SBS次之,MSBM 相似文献
12.
《国际聚合物材料杂志》2012,61(2):143-156
Dynamic vulcanization of a soft grade of thermoplastic natural rubber (TPNR) was carried out using several concentrations of Hexamethylene N, N′ bis (tert-butyl peroxy carbamate) (HBTP). The blends were melt mixed in a Brabender plasticorder. The effectiveness of dynamic vulcanization was investigated using the Brabender plastograms, swelling index measurements, rheological behavior by means of a capillary rheometer, dynamic mechanical properties, and tensile testing. It was found that varying the HBTP concentration had a great influence on the rheological behavior as well as the dynamic and tensile properties of the material. The increase of HBTP dosage resulted in an increase of the extent of crosslinking and caused an increase of the elastic modulus and a reduction of the loss modulus. The ultimate tensile strength and elongation at break also increased with increasing HBTP loading. The rheograms indicated that the blends exhibit a pseudoplastic behavior. 相似文献
13.
14.
15.
多孔物质的表面结构可以用分形维数D来表征,D与微孔结构存在对应的关系,不同的表面分形维数对应不同的微孔结构.详细讨论了分形维数和微孔结构随压力的变化规律.随着压力的增大,多孔介质表面形成更小的吸附微孔,孔径分布广.表面变得更粗糙,分形维数增大,至到趋于稳定值.分形维数表达表面结构简洁明了. 相似文献
16.
氯化乙丙橡胶增容PVC/SBS共混体系的研究 总被引:1,自引:0,他引:1
以氯化乙丙橡胶(CEPDM)为相容剂,研究了SBS对PVC的共混增韧改性。结果表明CEPDM能明显改善SBS与PVC的相容性,使共混物中SBS颗粒尺寸明显减小,分布更均匀,共混物的t_g内移,常温和低温下缺口冲击强度增大。当PVC/SBS/CEPDM为80/20/6(质量比)时,共混物的常温缺口冲击强度为56.3kJ/m~2,低温(-20℃)缺口冲击强度为32.4kJ/m~2。 相似文献
17.
PF与PVB共混炭化制备双电层电容器用多孔炭材料的研究 总被引:8,自引:0,他引:8
以酚醛树脂(PF)为原料,聚乙烯醇缩丁醛(PVB)为成孔剂,采用聚合物共混炭化法制备双电层电容器用多孔炭材料。通过热重(TG)和差热(DTA)分析,初步探讨了单一PF、PVB和PF、与PVB的共混物在炭化过程中的热解行为。考察了炭化温度和PF/PVB质量比对所得多孔炭的收率、BET比表面积、孔径分布和比电容的影响,并进一步探讨了以这种多孔炭材料作电极的模拟双电层电容器的充放电特性。结果表明,共混聚合物中PF与PVB是不相容的,热解过程各自独立进行,但存在一定的协同作用。随着炭化温度的升高,所得多孔炭的收率下降,比表面积、总孔容积和比电容先增大后减小,在800℃时达到最大值。随着PF/PVB质量比的增加,所得多孔炭的收率增加,比表面积和总孔容减小,比电容也减小。聚合物的混合方式及状态也是影响多孔炭性能的因素之一。以比电容为26.3F/g的多孔炭作电极的模拟双电层电容器具有良好的充放电性能。 相似文献
18.
热塑/热固共混树脂胶膜对复合材料抗冲击损伤性能影响 总被引:2,自引:0,他引:2
本文利用溶液共混法制备PEI/BMI/DBPA和PSF/BMI/DBPA两种热塑/热固共混权脂胶膜,分别有选择地夹入于复合材料叠层板层间,分析研究它们对复合材料抗低速冲击损伤性能的影响。实验结果表明,这种增韧性方法具有良好的成型工艺性,制备的复合材料与未增韧的相比,分层损伤能量阈值EC2提高50%以上,叠层板分层扩展阻力值R提高了两至三倍。 相似文献
19.
Yuji Tatemoto Yoshiyuki Bando Keiji Yasuda Yoshitaka Senda Masaaki Nakamura 《Drying Technology》2001,19(7):1305-1318
The drying characteristics of porous material in fluidized bed were examined theoretically and experimentally. The brick ball was used as the sample and immersed in the fluidized bed. The glass beads were used as the fluidizing particles and the particle diameters were changed. When the pore diameter of sample was relatively large, the fluidizing particles were adhered on the sample surface. In the theoretical analysis, the heat and mass transfers in adhered particle layer were considered. The fluidizing particles were adhered on the sample surface during the earlier period of drying. The sample temperature largely decreased when the mass of adhered particle decreased. The calculated results are in good agreement with experimental data. The diameter of fluidizing particle had a small effect on the drying time. The excess increments in drying gas temperature hardly contributed to shortening the drying time. 相似文献