Chemistry can be defined as the study of matter and the changes it undergoes. You¡¯ll sometimes hear it called the central science because it is the connection between physics and all the other sciences, starting with biology. 4897-84-1, Name is Methyl 4-bromobutanoate, molecular formula is , belongs to esters-buliding-blocks compound. In a document, author is Liu Xuan, Recommanded Product: Methyl 4-bromobutanoate.
Infectious Effect of Organic Small Molecules on Photo-oxidative Aging of Polypropylene
Aging of a polymer is generally affected by adjacent polymers, known as infectious behavior of aging. Organic small molecules generated during aging are considered to be infection agents. However, the way they influence aging process and the difference among various infection agents are still unknown. In this paper, the influence of 18 representative organic small molecules on photo-oxidative aging of polypropylene (PP) was studied. The small molecules included acids, esters, aldehydes, ketones and alcohols, corresponding to typical photo-oxidative degradation products of polymers. When they were placed near PP during aging, the carbonyl index (CI) of PP was higher compared to the case when PP was aged individually. It was demonstrated that photo-oxidative aging of PP was accelerated by all the small molecules. The acceleration effects of acids, aldehydes and ketones were outstanding. Especially for propanoic acid, isobutyric acid, methacrylic acid, formaldehyde, acetaldehyde and butanone, CI was increased by more than 700% when PP was aged with them. Further, infection mechanism of acetone and acetic acid was investigated , since they had been identified as typical infection agents. CI and concentrations of gaseous degradation products of PP with and without acetone or acetic acid were measured with aging time. When PP was aged with acetone, CI was increased from as early as 24 h at an extremely high rate. With acetic acid, CI was increased after an obvious induction period and the increasing rate was lower than that with acetone. Similar phenomenon was observed in gaseous degradation products. The results showed that acetone acted as an initiator, photolyzed to generate CH3 center dot that could initiate the oxidation of PP; while acetic acid acted as a catalyzer, facilitating the decomposition of hydroperoxides and the accumulation of oxidation products.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 4897-84-1, in my other articles. Recommanded Product: Methyl 4-bromobutanoate.