GB862567A - Improvements in the depolymerisation of cyclic polymers of epsilon-caprolactam - Google Patents
Improvements in the depolymerisation of cyclic polymers of epsilon-caprolactamInfo
- Publication number
- GB862567A GB862567A GB1623057A GB1623057A GB862567A GB 862567 A GB862567 A GB 862567A GB 1623057 A GB1623057 A GB 1623057A GB 1623057 A GB1623057 A GB 1623057A GB 862567 A GB862567 A GB 862567A
- Authority
- GB
- United Kingdom
- Prior art keywords
- distilling
- reduced pressure
- cyclic
- caprolactam
- base
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/02—Preparation of lactams
- C07D201/12—Preparation of lactams by depolymerising polyamides
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Polyamides (AREA)
Abstract
Monomeric e -caprolactam is prepared by distilling a cyclic polymer thereof under reduced pressure in the presence of about 1-2% by weight of a strong inorganic base. The cyclic dimer is specifically mentioned. Sodium hydroxide is the specified base. It is preferred to heat the cyclic polymers with the base at atmospheric pressure before distilling under reduced pressure. The reduced pressure may be from 50 to 500 mm. Hg. The reaction may be operated batchwise, semi-continuously, e.g. by distilling off about half the initial charge and then making up the liquid level with more polymer, or continuously. The product may be purified by first extracting it with water, then distilling the water and lactam successively, fractionating the distillate and recrystallising, e.g. from cyclohexane containing 2% by volume of chloroform.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1623057A GB862567A (en) | 1957-05-22 | 1957-05-22 | Improvements in the depolymerisation of cyclic polymers of epsilon-caprolactam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1623057A GB862567A (en) | 1957-05-22 | 1957-05-22 | Improvements in the depolymerisation of cyclic polymers of epsilon-caprolactam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB862567A true GB862567A (en) | 1961-03-15 |
Family
ID=10073528
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1623057A Expired GB862567A (en) | 1957-05-22 | 1957-05-22 | Improvements in the depolymerisation of cyclic polymers of epsilon-caprolactam |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB862567A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1500647A1 (en) * | 2003-07-23 | 2005-01-26 | Zimmer Aktiengesellschaft | Process for the treatment of polyamide containing waste by recycling of the depolymerization residue |
-
1957
- 1957-05-22 GB GB1623057A patent/GB862567A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1500647A1 (en) * | 2003-07-23 | 2005-01-26 | Zimmer Aktiengesellschaft | Process for the treatment of polyamide containing waste by recycling of the depolymerization residue |
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