The second consideration for selecting plasticizer varieties for blown film-Aging resistance

The second consideration for selecting plasticizer varieties for blown film- Aging resistance

The aging performance of PVC blown film is related to plasticizer and stabilizer. The aging performance of different plasticizer varieties is also different. Generally speaking, comparing the aging resistance of agricultural films is usually comprehensively evaluated in terms of starting to stick or produce spots sooner or later, the rate of spot development, the degree of embrittlement, strength and elongation of the films. According to the results of comprehensive tests, when Petroleum Ester and dioctyl phthalate are used alone, their natural aging properties are better, and they can be dried for about two years ( Generally, when the film is folded in half, that is, it is brittle, or when the relative elongation reaches about 20%, it is considered to reach the end point of aging damage). In general, the faster the plasticizer volatilizes, the lower the elongation retention rate after aging, and the volatility and atmospheric aging resistance of dioctyl phthalate and petroleum ester are relatively close, however, the tensile strength and elongation retention rate of petroleum ester are higher than that of dioctyl phthalate, but the aging and discoloration of petroleum ester are relatively rapid in the later stage of exposure.

dibutyl phthalate has poor atmospheric aging resistance due to its high volatility, heating loss and large water extract.

due to the poor miscibility of chlorinated paraffin and polyvinyl chloride, the aging resistance is correspondingly poor, but its water extraction property in the buried part is better, therefore, an appropriate proportion can be incorporated into the formula.

at 6050 ° C constant temperature in the oven, take the soil from the paddy fields of Shanghai suburbs, bury the sample directly, and keep the soil moist.

diphenyl-octyl phosphate is better than dioctyl phthalate in aging performance. Judging from the aging speed of the buried part of the agricultural film, diphenyl phosphate-octyl phosphate does not show its advantages.