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Various polysulfonamide(PSA) statistical copolymers were synthesized by polycondensation of three aromatic diamines and terephthaloyl chloride.The inherent viscosities of the resulting PSA copolymers range from 1.54 to 1.66 dL/g.The precipitated PSA copolymers with feed content of p-phenylene diamine(PPD) being less than 50%(mole fraction) can be redissolved in N-methyl-2-pryrrolidone(NMP) or N,N-dimethylacetamide(DMAc) with lithium chloride of wLiCl=0.02.All of the PSA copolymers exhibit enhanced tensile s... 相似文献
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为解决山区高速公路路线设计方面的问题,在介绍常见问题及其产生原因的基础上,提出相应的解决对策,以期为相关人员提供参考,保证山区高速公路路线设计质量,为之后的公路建设与运营创造良好条件。 相似文献
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