Ziegler-Natta catalyzed polyisoprene articles
A polymeric article comprises an elastomeric layer comprising cured synthetic polyisoprene particles that comprise a Ziegler-Natta catalyzed polyisoprene.
1. A polymeric article comprising:
an elastomeric layer comprising cured synthetic polyisoprene particles that comprise a Ziegler-Natta catalyzed polyisoprene material comprising:
a cis-1,4 isomer content of greater than or equal to 95% by weight to less than or equal to 97% by weight;
a trans-1,4 isomer content of 1% by weight or less; and
a 3,4 isomer content of 5% by weight or less;
wherein the synthetic polyisoprene particles are pre-vulcanized, the synthetic polyisoprene particles are bonded to each other through intra-polyisoprene particle crosslinks and inter-polyisoprene particle crosslinks, and the intra-polyisoprene particle crosslinks and inter-polyisoprene particle crosslinks comprise sulfur-crosslinks, and
wherein the elastomeric layer comprises a post-vulcanized structure having a molecular weight between crosslinks (Mc) of less than 11,000 g/mol.
2. The polymeric article of claim 1 , wherein the Ziegler-Natta catalyzed polyisoprene material comprises a cis-1,4 isomer content of about 96% to 97% by weight.
3. The polymeric article of claim 1 , wherein the article has a thickness in the range of from 0.030 to 0.065 mm.
4. The polymeric article of claim 1 , wherein the synthetic polyisoprene particles have a median particle diameter in the range of approximately from 0.2 to 2 micrometers.
5. The polymeric article of claim 1 in the form of a condom, a finger cot, or a glove.
6. A prophylactic device comprising:
an elastomeric layer comprising cured synthetic polyisoprene particles that are pre-vulcanized, intra-polyisoprene particle sulfur-crosslinks, and inter-polyisoprene particle sulfur-crosslinks,
wherein the synthetic polyisoprene particles comprise a Ziegler-Natta catalyzed polyisoprene material that comprises:
a cis-1,4 isomer content of greater than or equal to 95% by weight to less than or equal to 97% by weight;
a trans-1,4 isomer content of 1% by weight or less; and
a 3,4 isomer content of 5% by weight or less; and
wherein the elastomeric layer comprises a post-vulcanized structure having a molecular weight between crosslinks (M c ) of less than 11,000 g/mol.
7. The prophylactic device of claim 6 in the form of a condom, wherein the elastomeric layer forms an open end, a closed end, and a tubular sheath extending from the closed end to the open end.
8. The prophylactic device of claim 6 , wherein the synthetic polyisoprene particles have a median particle diameter in the range of approximately from 0.2 to 1.5 micrometers.
9. A method for producing a polymeric article, comprising:
pre-vulcanizing a Ziegler-Natta catalyzed polyisoprene material in the presence of a pre-vulcanization composition, wherein the pre-vulcanization composition comprises: sulfur, a dithiocarbamate accelerator, and a surfactant;
disposing an elastomeric coating of a Ziegler-Natta catalyzed polyisoprene material comprising: a cis-1,4 isomer content of greater than or equal to 95% by weight to less than or equal to 97% by weight; a trans-1,4 isomer content of 1% by weight or less; and a 3,4 isomer content of 5% by weight or less on a former;
curing the elastomeric coating to form an elastomeric layer of the polymeric article; and
adding a post-vulcanization composition to the emulsion after the Ziegler-Natta catalyzed polyisoprene material is pre-vulcanized, wherein the post-vulcanization composition comprises an accelerator;
wherein the synthetic polyisoprene particles are bonded to each other through intra-polyisoprene particle crosslinks and inter-polyisoprene particle crosslinks, and the intra-polyisoprene particle crosslinks and inter-polyisoprene particle crosslinks comprise sulfur-crosslinks.
10. The method of claim 9 , wherein the disposing of the elastomeric coating on the former comprises dipping the former into an emulsion of the Ziegler-Natta catalyzed polyisoprene material.
11. The method of claim 9 , wherein the polymeric article comprises a prophylactic device.
12. The method of claim 9 , wherein the elastomeric layer comprises a post-vulcanized structure having a molecular weight between crosslinks (M c ) of less than 11,000 g/mol.
13. The method of claim 9 , wherein the post-vulcanization composition further comprises amorphous sulfur or polysulfur.
14. The method of claim 9 , wherein the former is a coagulant-free former.
15. The method of claim 9 , wherein the accelerator comprises one or more of: zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), sodium diethyldithiocarbamate (SDEC), sodium dibutyldithiocarbamate (SDBC), a thiuram compound, and a xanthogen.