| 查看: 325 | 回复: 2 | |||
| 当前主题已经存档。 | |||
[交流]
30金币一段求助汉译英
|
|||
|
十分惭愧，外语水平太差，请求高手帮忙翻译！ 第一段：在过硫酸钾的浓度为1.0 mg/mL，转速为230 r/min的条件下考查了反应体系中单体的浓度对聚苯乙烯粒径及分布的影响，结果如图2所示。图2所示的为不同单体浓度下的聚苯乙烯微球的平均粒径及标准偏差的分布。从图2可以看出，随着单体浓度的增加，聚苯乙烯微球的平均粒径是先增大，再减小，标准偏差也是是同样的趋势，先增大，再减小。当单体的浓度为0.08g/mL时，粒径为1.4μm，此时粒径分布最窄。上述现象产生的原因可理解为随着单体浓度的增加，聚合物起始生成的“微球核”的溶解性增加，从而使聚合物颗粒数变少，使粒径增大，另一方面，单体浓度增加，反应速度加快，在相同时间生成较大粒子。在无乳化剂条件下，反应体系主要依靠结合在大分子链末端引发剂残基（-SO-4）而稳定，随单体浓度增加，体系中的聚合物含量增大，因为引发剂浓度不变，固使单位乳胶粒所能结合的电荷密度下降，为了维持乳液体系的稳定，粒子只有通过增大粒径而降低比表面积，所以乳胶粒子的粒径变大，分布变宽。 第二段：搅拌是无皂乳液聚合乳化过程中的必要条件。搅拌帮助液滴分散，将单体分散为液滴，强化传热。在单体浓度为0.08 g/mL，过硫酸钾的浓度为1.0 mg/mL的条件下考查了转速对聚苯乙烯粒径及分布的影响，结果如图3所示。 从图3可以明显看出随着转速的增大，平均粒径是先增大再减小，粒径分布也是先变宽在变窄。转速为370r/min时，粒径最大为1.9μm，标准偏差也最大标准偏差为0.6,当转速为230r/min时，平均粒径为1.4 μm，标准偏差也是最小为0.022。产生以上现象的原因可能是由于乳液体系主要依靠结合在大分子链末端且分布于粒子表面的引发剂残基（-SO-4）使电荷稳定，因为加入的引发剂和单体的浓度相同，产生的自由基数也相同，当转速较低时，在反应初期，粒子表面的电荷急剧增加，使得粒子间相互排斥，体系处于稳定，粒径较小。当转速增加时粒子间的稳定性被切应力打破，使体系处于不稳定的状态，粒子只有通过聚并使其稳定，粒径增大，分布变宽。当转速增至470r/min时，切应力使粒子间无法聚并，并处于稳定状态，所以粒径又较小，分布也较窄。 |
回复此楼» 猜你喜欢
（调剂）一志愿报考哈尔滨工业大学0857资源与环境专业378分考生
已经有6人回复
-
262求调剂
已经有7人回复
-
材料专硕322分
已经有10人回复
-
材料调剂
已经有8人回复
-
085600，320分求调剂
已经有8人回复
-
一志愿 江南大学 085602 化工专硕 338分求调剂
已经有11人回复
-
求调剂
已经有6人回复
-
086000调剂
已经有3人回复
-
求调剂
已经有4人回复
-
0703调剂，一志愿天津大学319分
已经有4人回复
★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★
meilan9(金币+30,VIP+0):谢谢， 6-1 17:52
meilan9(金币+30,VIP+0):谢谢， 6-1 17:52
|
第二段：搅拌是无皂乳液聚合乳化过程中的必要条件。搅拌帮助液滴分散，将单体分散为液滴，强化传热。在单体浓度为0.08 g/mL，过硫酸钾的浓度为1.0 mg/mL的条件下考查了转速对聚苯乙烯粒径及分布的影响，结果如图3所示。 从图3可以明显看出随着转速的增大，平均粒径是先增大再减小，粒径分布也是先变宽在变窄。转速为370r/min时，粒径最大为1.9μm，标准偏差也最大标准偏差为0.6,当转速为230r/min时，平均粒径为1.4 μm，标准偏差也是最小为0.022。产生以上现象的原因可能是由于乳液体系主要依靠结合在大分子链末端且分布于粒子表面的引发剂残基（-SO-4）使电荷稳定，因为加入的引发剂和单体的浓度相同，产生的自由基数也相同，当转速较低时，在反应初期，粒子表面的电荷急剧增加，使得粒子间相互排斥，体系处于稳定，粒径较小。当转速增加时粒子间的稳定性被切应力打破，使体系处于不稳定的状态，粒子只有通过聚并使其稳定，粒径增大，分布变宽。当转速增至470r/min时，切应力使粒子间无法聚并，并处于稳定状态，所以粒径又较小，分布也较窄。 The second paragraph: Agitation was necessary conditions in the process of polymerization of soap-free emulsion. The droplet was stirred to help dispersed, dispersed monomer to droplets, enhanced heat transfer. Under the conditions of 0.08 g / mL monomer and 1.0 mg / mL persulfate potassium, effect of rotate speed on polystyrene particle size and distribution was tested and the result were shown in figure 3. From Figure 3, it was clear that with the increasing of rotate speed , the average particle size first increased then decreased, and particle size distribution first broaded then narrowed. Rotate speed reached 370r/min, the maximum diameter was 1.9μm, the standard deviation was also the largest and reached 0.6, when rotate speed reached 230r/min, the average size was 1.4 μm, the minimum standard deviation reached 0.022. Reasons for the above could be attributed to the stability of charge mainly depends on the initiator residue (-SO-4) which the combinated on the end of the macromolecular chain and distributed on the particle surface, the identical amount of free radical was produced due to addition of initiator and monomer with the same concentration, when the speed was low, in response to the initial stage of the charge particle surface increased dramatically, presented mutually exclusive particles, the system with smaller particle size was stable. When the speed increased, the stability of particles by shear stress was broken, so that the system was unstable, the particles coalesced together, particle size increased, the distribution broadened. When the speed reached 470r/min, so that particles stress cuold not aggregate and was in stable state due to the shear, so particle size became smaller and particle distribution narrowed. |
2楼2009-06-01 16:41:38
★ ★ ★ ★ ★ ★ ★ ★ ★ ★
meilan9(金币+10,VIP+0):着急,今上午,已经翻译完了,但还是非常感谢! 6-2 20:32
meilan9(金币+10,VIP+0):着急,今上午,已经翻译完了,但还是非常感谢! 6-2 20:32
|
第一段：在过硫酸钾的浓度为1.0 mg/mL，转速为230 r/min的条件下考查了反应体系中单体的浓度对聚苯乙烯粒径及分布的影响，结果如图2所示。图2所示的为不同单体浓度下的聚苯乙烯微球的平均粒径及标准偏差的分布。从图2可以看出，随着单体浓度的增加，聚苯乙烯微球的平均粒径是先增大，再减小，标准偏差也是是同样的趋势，先增大，再减小。当单体的浓度为0.08g/mL时，粒径为1.4μm，此时粒径分布最窄。上述现象产生的原因可理解为随着单体浓度的增加，聚合物起始生成的“微球核”的溶解性增加，从而使聚合物颗粒数变少，使粒径增大，另一方面，单体浓度增加，反应速度加快，在相同时间生成较大粒子。在无乳化剂条件下，反应体系主要依靠结合在大分子链末端引发剂残基（-SO-4）而稳定，随单体浓度增加，体系中的聚合物含量增大，因为引发剂浓度不变，固使单位乳胶粒所能结合的电荷密度下降，为了维持乳液体系的稳定，粒子只有通过增大粒径而降低比表面积，所以乳胶粒子的粒径变大，分布变宽。 The first paragraph: Under the conditions of 1.0 mg / mL potassium persulfate and 230 r / min rotation speed, effect of concentration of monomer in the reaction system on polystyrene particle size and distribution was discussed and the result was shown in Figure 2. The mean diameter and standard deviation distribution of polystyrene microspheres with different monomer concentrations was shown in Figure 2. As can be seen from Figure 2, mean particle size of polystyrene microspheres as well as standard deviation first increased then decreased. When the concentration of monomer and particle size reached 0.08g/mL and 1.4μm respectively, the particle size distribution was narrowest. The reason for the above phenomena could be attributed to the increase of solubility of microspheres nuclear generated from polymer at the beginning with the increase of monomer concentration, as a result, the number of polymer particles decreased and particle size increased, on the other hand , monomer concentration increased and reaction speed accelerated and generated bigger particles in identical time. In the absence of emulsifier, the stabilization of reaction system mainly depended on combination with the end of the macromolecular chain initiator residue (-SO-4), the content of polymer system increased with the increase of monomer concentration, because the initiator concentration did not altered in unit, the charge density with which solid latex particles combined decreased, in order to the stability of emulsion system, particle size only reduced the specific surface area by increasing of particle size, so the particle size of latex particles became larger and distribution became wider. |
3楼2009-06-02 10:58:17
