PlasticizerAgentClassification, there are different classification methods according to different standards, Generally They can often be divided into two categories based on compatibility.
(1) The main plasticizer has high compatibility with the polymer and can be added in large amounts (in the polymer More than 50 parts of vinyl chloride can be added without leakage and can be used alone.
(2) The auxiliary plasticizer has poor compatibility with the plasticized polymer. If the amount exceeds a certain amount, it will leak out and cannot be used alone.
Press Plastic plasticizer The characteristics and use effects of span> can be divided into cold-resistant plasticizers, heat-resistant plasticizers, flame-resistant plasticizers, non-toxic plasticizers, etc.
According to chemical structure, plasticizers can be divided into phthalate esters, aliphatic dicarboxylic acid esters, and phosphoric acid esters Esters, epoxy compounds, etc.
The development of water-based plasticizers is compatible with the development of polyvinyl chloride, and there is basically a certain proportional relationship. The current development trend of plasticizers is to make full use of new raw material resources, especially petrochemical resources; in terms of varieties, develop new varieties with special properties.
With the development of petrochemical industry, aromatization technology provides a large amount of xylene and polytoluene, which can be oxidized The production of benzoic acid, benzene polycarboxylic acid and corresponding anhydrides, especially phthalic anhydride, expanded the raw materials of benzene from benzene to xylene. This promoted the development of phthalate ester plasticizers. The supply of benzene polycarboxylic acid and its anhydride has opened up raw material sources for new varieties of water-based plasticizers.
In addition, many new synthetic technologies provide many synthesis methods for intermediate and higher monohydric alcohols. The biggest contribution here is the carbonyl group The synthesis method can convert abundant petrochemical products such as propylene, isobutylene, etc. into many intermediate and high-grade monoalcohols. For example, using propylene as the orthocline, n-butyraldehyde can be made by using the base-shifting synthesis method, and n-butyraldehyde and isobutanol can be further synthesized.
n-Butyraldehyde undergoes aldol condensation reaction, dehydration and hydrogenation to obtain 2-ethylhexanol, which is the industrial Your ‘octanol’ in custom.
If propylene is dimerized, 2-methyl-1-pentene can be obtained, and then oxo-synthesized, After hydrogenation, a mixture of 3-methylhexanol and 2,2-dimethylpentanol can be obtained, which can be directly used as a raw material for the synthesis of plastic hope enhancers. This is generally known as ‘heptanol’.
Similarly, propylene is trimerized, and then undergoes oxo synthesis and hydrogenation to obtain “decanol” (also called isopropyl alcohol). Decanol); tetramerization, and then through oxo synthesis and hydrogenation, ‘tridedecanol’ is obtained. Isobutylene is dimerized, and then undergoes oxo synthesis and hydrogenation to obtain “nonanol”.
As can be seen from the above, the alcohols produced by oxo synthesis and hydrogenation using propylene and isobutylene as raw materials are all primary alcohols , except for n-butanol, are all branched.
The oxo synthesis method has undergone new developments in recent years. Due to improvements in catalysts, the reaction pressure can be greatly reduced, making it more convenient. It provides a large amount of medium and high-grade monohydric alcohols as raw materials for the PVC plasticizer industry.
In addition to ball-based synthesis, it also There is alkyl aluminum method. It uses pure aluminum, ethylene and oxygen to react to first produce alkyl aluminum, and then oxidizes it with air and then hydrolyzes it to obtain higher monohydric alcohols.
This method mainly produces mixed linear high-grade monohydric alcohols. Controlling certain reaction conditions can control the length of the alcohol molecular chain. In addition to ethylene, propylene, and isobutylene, paraffin cracking produces so-called α-olefins with double bonds at the chain ends, which can also be used as raw materials for the synthesis of medium and high-grade monoalcohols.
Α-olefin can also be added to HBr and then hydrolyzed in an alkaline solution to produce intermediate or higher monohydric alcohols .
