The structural analysis of two PP/PE copolymer samples, 1 and 2, was conducted by using C-13-NMR, GPC and crystallization segregation DSC (CSDSC) techniques. A pure polypropylene sample was also used for comparison. I...The structural analysis of two PP/PE copolymer samples, 1 and 2, was conducted by using C-13-NMR, GPC and crystallization segregation DSC (CSDSC) techniques. A pure polypropylene sample was also used for comparison. It was found that the two copolymer samples are very close in composition (the ethylene mol content is 4.3% and 4.5%, respectively), stereoregularity (96% and 97%) and molecular weight (M-w = 7.0 x 10(4) and 7.3 x 10(4); M-w/M-n = 5.0 and 6.1, respectively). While the CSDSC thermograms of the two samples are quite different from each other. Sample 1 shows a higher average melting temperature and a broader distribution of its thermogram These phenomena were explained as an indication of a less uniform distribution of ethylene units along the PP chains for sample 1. It was noted that CSDSC is a very sensitive and convenient technique for structural studies of copolymers.展开更多
A new kind of high performance composite resin matrix PEEK/PES, PEEKK/PES block copolymers have been prepared from the corresponding oligomers via a nucleophilic aromatic substitution reaction. The different propertie...A new kind of high performance composite resin matrix PEEK/PES, PEEKK/PES block copolymers have been prepared from the corresponding oligomers via a nucleophilic aromatic substitution reaction. The different properties of the copolymers are investigated by differential scanning calorimetry (d. s. c), thermogravimetric analysis (t. g. a) and dynamic mechanical analysis (d. m. a). The results show that the relationship between Tg and the compositions of the copolymers approximately follows the formula 1/Tg=W1/Tg1 +W2/Tg2 for PEEKK/PES block copolymers, and Tg=Tg1W1 +Tg2W2 for PEEK/PES block copolymers. The PES content and the segment length of the copolymers have a significant influence on their melting point. The thermal properties and dynamic mechanical behaviour of the copolymers are also studied. The introduction of PES segment into the molecular main chain increases the glass transition temperature of poly aryl ether ketones and decreases their melting temperature, that is to say it decreases their melting processing temperature. The block copolymers keep the high temperature stability and solvent resistance of poly aryl ether ketones. They are expected to be a new kind of high performance composite resin matrix.展开更多
The interface and surface properties of nano-hydroxyapatite(n-HA) and poly(1,4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some...The interface and surface properties of nano-hydroxyapatite(n-HA) and poly(1,4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some strong interface combinations of calcium ion (Ca2+), carboxyl (-COO-) and phosphate radicle ion (PO3-4) between copolymer and n-HA in the composite. The presence of the 2,4-phenylene sulfide acid in copolymer can increase the affinity to n-HA, which causes the formation of chemical bindings between the PPS-PPSA copolymer and n-HA. XRD analysis and IR surface analysis indicate that n-HA is not encapsulated by copolymer but exposed on the surface of the composite, and has same structure and properties with the original n-HA. The presence of the interface chemical bindings between the PPS-PPSA copolymer and n-HA can increase the content of n-HA in composite but does not cause the decrease of the composite mechanical strength.展开更多
目的以PE,PP为原料,接枝马来酸酐(MAH)后,与高岭土经双螺杆挤出机熔融共混挤出,制备PE-g-MAH/PP/高岭土复合材料。方法采用电子万能试验机分析复合材料的拉伸性能;采用电子悬臂冲击实验机分析材料的缺口冲击强度;采用水平垂直燃烧仪测...目的以PE,PP为原料,接枝马来酸酐(MAH)后,与高岭土经双螺杆挤出机熔融共混挤出,制备PE-g-MAH/PP/高岭土复合材料。方法采用电子万能试验机分析复合材料的拉伸性能;采用电子悬臂冲击实验机分析材料的缺口冲击强度;采用水平垂直燃烧仪测试分析复合材料的阻燃性;采用红外光谱仪分析复合材料的化学结构。结果含MAH质量分数为5%的PE与PP按质量比1∶1混合后,加入15%的高岭土,制备的PE-g-MAH/PP/高岭土复合材料拉伸强度、缺口冲击强度和断裂伸长率均为最佳,分别为10.925 MPa,40.6 k J/m2,89.5%;复合材料的阻燃性与高岭土加入量呈先快速增大后慢速降低趋势,加入量为15%时阻燃性最好;复合材料各组分间实现了化学键合。结论适量的高岭土提升了PE/PP复合材料的阻燃性,而MAH的加入改善了PE,PP和高岭土间的相容性。展开更多
文摘The structural analysis of two PP/PE copolymer samples, 1 and 2, was conducted by using C-13-NMR, GPC and crystallization segregation DSC (CSDSC) techniques. A pure polypropylene sample was also used for comparison. It was found that the two copolymer samples are very close in composition (the ethylene mol content is 4.3% and 4.5%, respectively), stereoregularity (96% and 97%) and molecular weight (M-w = 7.0 x 10(4) and 7.3 x 10(4); M-w/M-n = 5.0 and 6.1, respectively). While the CSDSC thermograms of the two samples are quite different from each other. Sample 1 shows a higher average melting temperature and a broader distribution of its thermogram These phenomena were explained as an indication of a less uniform distribution of ethylene units along the PP chains for sample 1. It was noted that CSDSC is a very sensitive and convenient technique for structural studies of copolymers.
文摘A new kind of high performance composite resin matrix PEEK/PES, PEEKK/PES block copolymers have been prepared from the corresponding oligomers via a nucleophilic aromatic substitution reaction. The different properties of the copolymers are investigated by differential scanning calorimetry (d. s. c), thermogravimetric analysis (t. g. a) and dynamic mechanical analysis (d. m. a). The results show that the relationship between Tg and the compositions of the copolymers approximately follows the formula 1/Tg=W1/Tg1 +W2/Tg2 for PEEKK/PES block copolymers, and Tg=Tg1W1 +Tg2W2 for PEEK/PES block copolymers. The PES content and the segment length of the copolymers have a significant influence on their melting point. The thermal properties and dynamic mechanical behaviour of the copolymers are also studied. The introduction of PES segment into the molecular main chain increases the glass transition temperature of poly aryl ether ketones and decreases their melting temperature, that is to say it decreases their melting processing temperature. The block copolymers keep the high temperature stability and solvent resistance of poly aryl ether ketones. They are expected to be a new kind of high performance composite resin matrix.
文摘The interface and surface properties of nano-hydroxyapatite(n-HA) and poly(1,4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some strong interface combinations of calcium ion (Ca2+), carboxyl (-COO-) and phosphate radicle ion (PO3-4) between copolymer and n-HA in the composite. The presence of the 2,4-phenylene sulfide acid in copolymer can increase the affinity to n-HA, which causes the formation of chemical bindings between the PPS-PPSA copolymer and n-HA. XRD analysis and IR surface analysis indicate that n-HA is not encapsulated by copolymer but exposed on the surface of the composite, and has same structure and properties with the original n-HA. The presence of the interface chemical bindings between the PPS-PPSA copolymer and n-HA can increase the content of n-HA in composite but does not cause the decrease of the composite mechanical strength.
文摘目的以PE,PP为原料,接枝马来酸酐(MAH)后,与高岭土经双螺杆挤出机熔融共混挤出,制备PE-g-MAH/PP/高岭土复合材料。方法采用电子万能试验机分析复合材料的拉伸性能;采用电子悬臂冲击实验机分析材料的缺口冲击强度;采用水平垂直燃烧仪测试分析复合材料的阻燃性;采用红外光谱仪分析复合材料的化学结构。结果含MAH质量分数为5%的PE与PP按质量比1∶1混合后,加入15%的高岭土,制备的PE-g-MAH/PP/高岭土复合材料拉伸强度、缺口冲击强度和断裂伸长率均为最佳,分别为10.925 MPa,40.6 k J/m2,89.5%;复合材料的阻燃性与高岭土加入量呈先快速增大后慢速降低趋势,加入量为15%时阻燃性最好;复合材料各组分间实现了化学键合。结论适量的高岭土提升了PE/PP复合材料的阻燃性,而MAH的加入改善了PE,PP和高岭土间的相容性。
