x**********1
发帖数: 28 | 1 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
。。。
还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
回氮气，反应在真空密闭的体系进行，室温25度。
具体原因还不是很清楚，大概分析如下：
1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
快，放热，然后爆炸。---想来想去这个最有可能！
2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
，低压下EO沸腾，瓶内压力增大爆炸。 ----之前查过，EO蒸汽压不是特别大的，所以
这个原因应该不成立吧？
3. 圆底烧瓶改装成的schlenk line flask 质量问题，有裂缝？ 耐不住高压？
真心求救，不知道原因前都不敢做下一锅了！ | y********1
发帖数: 565 | | g***e
发帖数: 584 | 3 不清楚，帮顶，我记得别人做是eo缓慢加入的啊，你这个是一次性加进去了？
,
【在 x**********1 的大作中提到】
: 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
: 。。。
: 还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
: 4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
: 真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
: 回氮气，反应在真空密闭的体系进行，室温25度。
: 具体原因还不是很清楚，大概分析如下：
: 1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
: 快，放热，然后爆炸。---想来想去这个最有可能！
: 2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
| b*****y
发帖数: 40 | 4 First very sorry about what happened. Hope nothing happened with the safety
of yourself.
The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
carcenogen, so give it with your highest care possible. That means, no
nights, no weekends, always have labmates nearby, among many other things.
Out of the three reasons, #1 is highly possible. Definitely dilute with much
much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
40 deg C. If you have done a good job in drying THF, a large quantity of
THF doesn't hurt the initiation. But, it will make the reaction slower, and
thus the heat can be slowly released and well dissipated. EO has excellent
solubility in THF.
#2 is very unlikely to be true.
#3 can't be eliminated, as it can give implosion. Always do a very careful
check for scratches. Use Chemglass flasks. Always kiln the glassware to 500
deg C before freeze-pump-thaw cycles.
Did you use a water bath to help control the temperature?
In addition, there are many PEOs commercially available. Always great to
check the catalog out first.
Take care and good luck next time!
,
【在 x**********1 的大作中提到】
: 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
: 。。。
: 还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
: 4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
: 真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
: 回氮气，反应在真空密闭的体系进行，室温25度。
: 具体原因还不是很清楚，大概分析如下：
: 1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
: 快，放热，然后爆炸。---想来想去这个最有可能！
: 2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
| y********1
发帖数: 565 | 5 good explanation. Maybe it is more helpful to paste your own procedure here.
safety
【在 b*****y 的大作中提到】
: First very sorry about what happened. Hope nothing happened with the safety
: of yourself.
: The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
: carcenogen, so give it with your highest care possible. That means, no
: nights, no weekends, always have labmates nearby, among many other things.
: Out of the three reasons, #1 is highly possible. Definitely dilute with much
: much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
: 40 deg C. If you have done a good job in drying THF, a large quantity of
: THF doesn't hurt the initiation. But, it will make the reaction slower, and
: thus the heat can be slowly released and well dissipated. EO has excellent
| j*********5
发帖数: 6221 | 6 你太小心了，我们公司做PEO基本都是15%左右的浓度，加热到50度，用史莱克瓶，从来
木有爆炸过
THF一定要dry
safety
much
at
and
【在 b*****y 的大作中提到】
: First very sorry about what happened. Hope nothing happened with the safety
: of yourself.
: The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
: carcenogen, so give it with your highest care possible. That means, no
: nights, no weekends, always have labmates nearby, among many other things.
: Out of the three reasons, #1 is highly possible. Definitely dilute with much
: much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
: 40 deg C. If you have done a good job in drying THF, a large quantity of
: THF doesn't hurt the initiation. But, it will make the reaction slower, and
: thus the heat can be slowly released and well dissipated. EO has excellent
| j*********5
发帖数: 6221 | 7 我们的做法是先干燥溶剂，用vac line 转入EO配成THF solution，然后封口拿到手套
箱里加Initiator，瓶子里应该是Ar和少量O2（我们的手套箱里氧气含量有点高），文
献的量是对的，不要配太高浓度，我们一般是15%，加热到50度
,
【在 x**********1 的大作中提到】
: 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
: 。。。
: 还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
: 4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
: 真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
: 回氮气，反应在真空密闭的体系进行，室温25度。
: 具体原因还不是很清楚，大概分析如下：
: 1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
: 快，放热，然后爆炸。---想来想去这个最有可能！
: 2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
| c***3
发帖数: 280 | | x**********1
发帖数: 28 | 9
safety
.....
谢谢大家的帮助，可能还是EO太浓的缘故。老板让下次做的时候不要瓶子封死，这样就
不会爆炸了。。。
【在 b*****y 的大作中提到】
: First very sorry about what happened. Hope nothing happened with the safety
: of yourself.
: The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
: carcenogen, so give it with your highest care possible. That means, no
: nights, no weekends, always have labmates nearby, among many other things.
: Out of the three reasons, #1 is highly possible. Definitely dilute with much
: much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
: 40 deg C. If you have done a good job in drying THF, a large quantity of
: THF doesn't hurt the initiation. But, it will make the reaction slower, and
: thus the heat can be slowly released and well dissipated. EO has excellent
| x**********1
发帖数: 28 | 10 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
。。。
还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
回氮气，反应在真空密闭的体系进行，室温25度。
具体原因还不是很清楚，大概分析如下：
1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
快，放热，然后爆炸。---想来想去这个最有可能！
2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
，低压下EO沸腾，瓶内压力增大爆炸。 ----之前查过，EO蒸汽压不是特别大的，所以
这个原因应该不成立吧？
3. 圆底烧瓶改装成的schlenk line flask 质量问题，有裂缝？ 耐不住高压？
真心求救，不知道原因前都不敢做下一锅了！ | | | y********1
发帖数: 565 | | g***e
发帖数: 584 | 12 不清楚，帮顶，我记得别人做是eo缓慢加入的啊，你这个是一次性加进去了？
,
【在 x**********1 的大作中提到】
: 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
: 。。。
: 还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
: 4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
: 真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
: 回氮气，反应在真空密闭的体系进行，室温25度。
: 具体原因还不是很清楚，大概分析如下：
: 1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
: 快，放热，然后爆炸。---想来想去这个最有可能！
: 2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
| b*****y
发帖数: 40 | 13 First very sorry about what happened. Hope nothing happened with the safety
of yourself.
The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
carcenogen, so give it with your highest care possible. That means, no
nights, no weekends, always have labmates nearby, among many other things.
Out of the three reasons, #1 is highly possible. Definitely dilute with much
much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
40 deg C. If you have done a good job in drying THF, a large quantity of
THF doesn't hurt the initiation. But, it will make the reaction slower, and
thus the heat can be slowly released and well dissipated. EO has excellent
solubility in THF.
#2 is very unlikely to be true.
#3 can't be eliminated, as it can give implosion. Always do a very careful
check for scratches. Use Chemglass flasks. Always kiln the glassware to 500
deg C before freeze-pump-thaw cycles.
Did you use a water bath to help control the temperature?
In addition, there are many PEOs commercially available. Always great to
check the catalog out first.
Take care and good luck next time!
,
【在 x**********1 的大作中提到】
: 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
: 。。。
: 还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
: 4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
: 真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
: 回氮气，反应在真空密闭的体系进行，室温25度。
: 具体原因还不是很清楚，大概分析如下：
: 1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
: 快，放热，然后爆炸。---想来想去这个最有可能！
: 2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
| y********1
发帖数: 565 | 14 good explanation. Maybe it is more helpful to paste your own procedure here.
safety
【在 b*****y 的大作中提到】
: First very sorry about what happened. Hope nothing happened with the safety
: of yourself.
: The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
: carcenogen, so give it with your highest care possible. That means, no
: nights, no weekends, always have labmates nearby, among many other things.
: Out of the three reasons, #1 is highly possible. Definitely dilute with much
: much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
: 40 deg C. If you have done a good job in drying THF, a large quantity of
: THF doesn't hurt the initiation. But, it will make the reaction slower, and
: thus the heat can be slowly released and well dissipated. EO has excellent
| j*********5
发帖数: 6221 | 15 你太小心了，我们公司做PEO基本都是15%左右的浓度，加热到50度，用史莱克瓶，从来
木有爆炸过
THF一定要dry
safety
much
at
and
【在 b*****y 的大作中提到】
: First very sorry about what happened. Hope nothing happened with the safety
: of yourself.
: The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
: carcenogen, so give it with your highest care possible. That means, no
: nights, no weekends, always have labmates nearby, among many other things.
: Out of the three reasons, #1 is highly possible. Definitely dilute with much
: much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
: 40 deg C. If you have done a good job in drying THF, a large quantity of
: THF doesn't hurt the initiation. But, it will make the reaction slower, and
: thus the heat can be slowly released and well dissipated. EO has excellent
| j*********5
发帖数: 6221 | 16 我们的做法是先干燥溶剂，用vac line 转入EO配成THF solution，然后封口拿到手套
箱里加Initiator，瓶子里应该是Ar和少量O2（我们的手套箱里氧气含量有点高），文
献的量是对的，不要配太高浓度，我们一般是15%，加热到50度
,
【在 x**********1 的大作中提到】
: 前两天第一次阴离子(萘钾)聚合EO, 反应在半夜中爆炸了，一片狼藉，吓出一身冷汗。
: 。。。
: 还好第一次用量不大：2 mmol 小分子醇引发剂，3 mL 萘钾THF（微过量）， 4mL EO,
: 4mL THF 反应。 圆底烧瓶改装成的schlenk line flask 先加入醇，THF 和萘钾，然后
: 真空转入EO反应。 实际转入的EO应该大于计算的4mL，大概在6-7mL。 EO转入后没有灌
: 回氮气，反应在真空密闭的体系进行，室温25度。
: 具体原因还不是很清楚，大概分析如下：
: 1. THF 太少，而实际加入的EO太多， 文献中THF：EO=5:1， 而我只有1:1。 EO聚合太
: 快，放热，然后爆炸。---想来想去这个最有可能！
: 2. 转入EO时 schlenk line flask 是真空，转完后没有通回氮气，然后又把烧瓶密闭
| c***3
发帖数: 280 | | x**********1
发帖数: 28 | 18
safety
.....
谢谢大家的帮助，可能还是EO太浓的缘故。老板让下次做的时候不要瓶子封死，这样就
不会爆炸了。。。
【在 b*****y 的大作中提到】
: First very sorry about what happened. Hope nothing happened with the safety
: of yourself.
: The b.p. of EO is only ~ 10 deg C, it is extremely flammable, and it is an
: carcenogen, so give it with your highest care possible. That means, no
: nights, no weekends, always have labmates nearby, among many other things.
: Out of the three reasons, #1 is highly possible. Definitely dilute with much
: much more THF. I typically have 40 grams of EO with ~ 800 mL of THF, but at
: 40 deg C. If you have done a good job in drying THF, a large quantity of
: THF doesn't hurt the initiation. But, it will make the reaction slower, and
: thus the heat can be slowly released and well dissipated. EO has excellent
|
|
