从图中可以发现共聚物A，B的黏度都随剪切速率的增加而减小，是典型的假塑性流体。在剪切速率较低（小于500 s-1）时，两种共聚物的黏度随剪切速率变化都比较小，相同剪切速率下，A的黏度要略低于B。当剪切速率继续增加时（大于500 s-1），A和B的黏度继续减小，但B黏度随剪切速率变化更快，相同剪切速率下A的黏度大于B的黏度。2.注塑成型汽车用蓄电池壳，要求尺寸稳定性好，强度高，抗蠕变性能好，滞后现象小，应选择A，相比于B，A对剪切速率更不敏感，说明A的分子链刚性更大，分子间作用力更强，成型后材料的尺寸稳定性和抗蠕变性能也越好，在周期性外力作用下滞后现象更小。3.可以测A和B的熔融指数，这样可以更清楚地了解他们的流动性，为其成型工艺如压力、温度等提供依据；测定其分子量及其分布，分子量越大，分子间作用力越强，成型温度、压力越高；测定其熔点，熔点是加工的最低温度。5．某研究者做了如下实验：将部分马来酸酐接枝聚乙烯（MAH-g-PE）加入PA66中，经双螺杆挤出机共混后，注塑成型标准试样，测试标准试样的缺口冲击强度跟MAH-g-PE加入量的关系见下图。其中，曲线A为成型后，仅室温放置了24小时测得的结果；曲线B为成型后室温放置5周测得的结果。（1）请简要谈谈放置时间对材料韧性的影响，并解释其中的原因。（2）若用纯的PA66塑料加工齿轮，马上装配到某机械上并将机械投入使用，你预测齿轮在使用过程中可能出现什么问题。（3）为了克服（2）中的问题，若仅从成型加工方面考虑，应对齿轮做怎样的后处理，谈谈后处理对材料结构和性能有哪些方面的影响。（4.为了克服（2.中的问题，若从材料改性方面考虑，加入部分MAH-g-PE。试谈谈加入MAH-g-PE后，在成型加工工艺、制品后处理方面应做哪些调整，对制品其他性能有何影响。1.放置时间越长，韧性越差，因为PA66和PE存在后期结晶现象，所以试样会变硬，韧性变差。2.在使用过程中齿轮会变形，变脆。3.应该进行退火处理，通过退火可以消除制品中残留的内应力，防止翘曲变形，使制品的尺寸稳定性变好，另外可以使结晶更完善，力学强度提高4.MAH-g-PE一方面可以起到增韧作用，另一方面可以改善PA66的加工性能。加入MAH-g-PE后，成型温度可以适当降低，注射速率也可以降低点，制品的冲击强度会提高，尺寸稳定性提高，但是拉伸强度会降低，耐热性变差。6．图A和B和不相容共混物注塑试样的形态三维和二维模型（注意A和B中注塑工艺、模具是不同的）。（A）(B)（1）试分析图A和B包括哪几层结构，分散相形态有何特点。两者有何不同。皮层（固化层），过渡层（皮下层）和芯层。皮层含被拉伸的分散相粒子，过渡层含拉伸的分散相粒子和球状分散相粒子，芯层只含球状分散相粒子或椭球状分散相粒子。两者的不同点在于图B表示的是浇口中的熔体，随着流动方向，固化层逐渐变厚，芯层逐渐变薄；而图A表示的是制品的一部分，它的每一层的厚度都是均匀的。（2.图A和B各是单浇口模具还是多浇口模具。图A是多浇口模具；图B是单浇口模具。（3）形成这样的形态对制品性能有何影响？1.使制品产生内应力，使制品机械性能下降。2.但表面的分散相的取向有助于提高材料的力学性能，甚至可以产生二次屈服现象。两者相互竞争。（4）分析产生图B这样的形态的原因。请阅读下面一段话，对你分析有所帮助（仅共参考，一些参考文献未列出，图10也未列出。其中的图9是下图B）。原因有三：第一，接触冷模具表面的熔体前端会形成相同厚度的固化层，接着的熔体遇到固化层后仍会冷却固化直到充模结束；第二，浇口部位的固化层比非浇口部位要经历更长的稠化时间；第三，一旦固化层形成，其表面的剪切速率变为0。剪切速率从0到最大只有离固化层表面很薄的一层。由于同样的原因，主要包含拉伸分散相粒子的皮下层随着流动方向变薄，而包含球状粒子的芯层变得越来越厚。（5）翻译带横线的一段话。Befor. mold filling. the preforme. dispersed PC and PET droplets mus. have already experienced some degree of stretching in the high shear and elongational flow fields during the previous blending process. The morphology evolution to the final solid-state structure after injection molding was determined by the flow fields experienced by the melt during mold filling,and the cooling rate during and after mold filling. The high shear and elongational fields during mold filling cause the deformation and also the break up and coalescence of the dispersed particles. The final shape and size of the injection-molded bar is the product of the balance between deformation, breakup and coalescence. In the case of non-isothermal flow, the velocity distribution across the thickness has an inflection point where the shear rate reaches the maximum [27], while the shear rate is zero at the mold surface and the center. The shear rate profile in two positions of the cross section from gate to non-gate end is schematically illustrated in Fig. 10. Compared to other shear rate profiles proposed in the literature [26], it presentsa solid.fie. layer with increasin. thickness along.melt flo. direction. The solidified layer wa. formed continuously until cessation of mold filling. The solidified layer shown in Fig. 9 contained elongated dispersed phase. That the solid layer close to the gate end was thicker is understandable because of the following facts:a. Even though the same thickness forms as the melt flow front touches the cold mold surfac. all along the mold, the material near the initial solid layer can continue to cool to solid until the cessation of mold filling.b. The solidified layer near the gate end experienced longer thickening time than that at the non-gate end.c. As soon as the solidified layer is formed, the shear rate in the previously solidified layer surface decreases to zero. Though the maximum shear rate appear. near the solidified layer surface, there exists a thin melt layer where the shear rate is relatively lowsince the shear rate changes continuously from zero at the surface of the solidified layer to the maximum at a point quite close to the solidified layer. Based on the same reason, the subskin layer, mainly comprised of elongated dispersed phase, turns thinner along the melt flowdirection, while the core layer containing mainly spherical domains gets thicker and thicker from gate to non-gate end.________________________