Process for the preparation of a vinylidene chloride polymer/clay composite, films obtained therefrom, and use thereof
The present invention relates to a process for preparing a vinylidene chloride polymer composite comprising a vinylidene chloride polymer and clay materials. The process comprises polymerising vinylidene chloride and clay materials and the resulting vinylidene chloride polymer particle is surrounded by a plurality of clay platelets. The clay materials according to the present invention function as a solid stabilizer in the process for preparing a vinylidene chloride polymer composite of the present invention. The present invention further relates to the vinylidene chloride polymer composite obtainable from the process, to use of the vinylidene chloride polymer composite for the preparation of films, and to films prepared therefrom.
1. A process for preparing a vinylidene chloride polymer composite, the process comprising:
adding vinylidene chloride and at least one ethylenically unsaturated monomer copolymerisable therewith to a dispersion, said dispersion comprising a clay material and a free radical initiator in a liquid phase; and
polymerising vinylidene chloride and said at least one ethylenically unsaturated monomer to form a vinylidene chloride polymer composite comprising a vinylidene chloride copolymer and the clay material,
wherein the amount of clay material ranges from 10.0 to 60.0 g per liter (“g L −1 ”) with respect to the liquid phase and wherein the copolymer has a percent by weight (wt %) of vinylidene chloride/said ethylenically unsaturated monomer from 82/18 to 93/7,
and wherein the liquid phase is water.
2. The process according to claim 1 , wherein the clay material surrounds the particle surface of the vinylidene chloride copolymer.
3. The process according to claim 1 , wherein the clay material is selected from the group consisting of montmorillonite, hectorite, laponite, saponite, mica, vermiculite, nontronite, beidellite, volkonskoite, kaolinite, serpentinite, and gibbsite.
4. The process according to claim 1 , wherein the clay material is laponite.
5. The process according to claim 1 , wherein the free radical initiator is selected from the group consisting of peroxides, hydroperoxides, azo compounds, redox compounds, and photoinitiators.
6. The process according to claim 1 , wherein the free radical initiator is an inorganic initiator.
7. The process according to claim 1 , wherein the amount of clay material ranges from 25.0 to 40.0 g L −1 with respect to the liquid phase, and wherein the vinylidene chloride copolymer has a wt % of vinylidene chloride/said ethylenically unsaturated monomer from 85/15 to 90/10.