НАФТАЛИН-1,5-ДИИЗОЦИАНАТ химические свойства, назначение, производство
Описание
Naphthalene diisocyanate (NDI) occurs as white to lightyellow
crystalline flakes with a characteristic odor. NDI is
incompatible with many classes of compounds, reacting
exothermically to release toxic gases. Reactions with amines,
aldehydes, alcohols, alkali metals, ketones, mercaptans, strong
oxidizers, hydrides, phenols, and peroxides can cause vigorous
releases of heat. Acids and bases initiate polymerization reactions.
NDI can react with water to form amines and liberate
carbon dioxide.
Химические свойства
Naphthylene 1,5-diisocyanate is a solid, m.p. 128°C. It has a lower vapour
pressure than tolylene diisocyanate and is therefore less toxic in use; it does,
however, have sensitizing properties.
Использование
Manufacture of polyurethane solid elastomers.
Подготовка
Naphthylene 1,5-diisocyanate (NDI) is prepared from naphthalene as follows:
![3173-72-6 synthesis](https://www.chemicalbook.com/NewsImg/2022-03-11/202103089759158517.jpg)
Общее описание
White to light-yellow crystalline flakes.
Профиль реактивности
Isocyanates and thioisocyanates, such as 1,5-Naphthalene diisocyanate, are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence, [Wischmeyer(1969)].
Опасность
Irritant. Questionable carcinogen.
Профиль безопасности
A powerful allergen. An
irritant. Questionable carcinogen. When
heated to decomposition it emits toxic
fumes of NOx.
Экологическая судьба
NDI is a synthetic organic chemical. It is a natural derivative of
primary amines with the general formula R–N]C]O which
does not occur naturally in the environment. At room temperature
it can be a liquid or crystal. It is miscible with alcohol,
diglycol, monoethyl ether, ether, acetone, carbon tetrachloride,
benzene, chlorobenzene, kerosene, and olive oil; however, it
may react violently with alcohol, water, acid, bases, and strong
alkaline materials and tertiary amines and generate enough heat
to self-ignite and release toxic combustion products. NDI is not
readily biodegradable; however, it reacts with water and most
acids producing unstable carbonic acids, which subsequently
decarboxylate yielding relatively chemically inert and insoluble
polymeric urea. While these polyureas are persistent, studies
have indicated that they pose virtually no potential for adverse
impacts on the aquatic environment. Due to hydrolysis in water,
bioaccumulation of NDI is not expected. Since the hydrolysis
products formed are irritants, there is a potential for inhalation
exposure. The degree stability is a function of humidity.
НАФТАЛИН-1,5-ДИИЗОЦИАНАТ препаратная продукция и сырье
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препарат