| 摘要 |
An aqueous suspension of polyvinyl acetate, modified by at least one alcohol, renders its residual evaporative product insoluble; in that it does not disintegrate and tend to revert to an aqueous suspension when immersed or otherwise subjected to an excess of water, as does the unmodified product. The modified evaporative product, used experimentally as a shielding film that protects plants and fruit from insect damage, does not depend on toxicity for effectiveness, and maintains its integrity by stretching and thinning to accommodate plant growth without rupture to provide uninterrupted protection between applications. The shielding transmits moisture and is believed to transmit needed atmospheric gases as well, to provide long lasting, primarily mechanical protection. The modified suspension, and evaporative product, have demonstrated medicinal properties as a topical treatment for control of psoriasis. Transparent, colorless and odorless when dry, it is anti-bacterial, provides relief from itching and promotes healing of lesions.
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