POM blending modified automotive glass sandwich film production line
日期：2021/7/28 9:03:05 / 閱讀： / 來源：本站
POM blending modified automotive glass sandwich film production linePOM / Copa blends were prepared by blending injection grade POM resin (m90-44, produced by Shanghai Baoli Plastics Co., Ltd.) and ternary copolymerized polyamide (Copa) resin (produced by Shanghai Celluloid factory, ternary copolymerized component PA6 / PA66 / PA1010 (mass ratio: 10:20:70, melting point: 155 ~ 175 ℃). With the increase of Copa content, the impact strength of the blends increased rapidly and peaked at 2%. After that, the impact strength of the blends began to decrease with the increase of Copa content. This is because when the amount of Copa is small (mass fraction is less than 4%), Copa cannot crystallize, and there is a certain degree of hydrogen bond between Copa and POM molecules. Therefore, the impact strength of the blends is greatly improved; When the amount of Copa is large (such as mass fraction greater than 5%), Copa will crystallize itself, resulting in phase separation, which will rapidly reduce the impact strength of the blends. The blends were plasticized at 165 ~ 170 ℃ and 190 ~ 195 ℃ for 5 minutes, and then tested by tablet pressing. The results showed that the mixing temperature had a great effect on the impact strength of the blends. The impact strength at 165 ~ 170 ℃ is much higher than that at 190 ~ 195 ℃. This is because POM is a heat sensitive plastic. Under the joint action of heat and oxygen, dealdehyde reaction will occur, and the removed formaldehyde will be oxidized to formic acid, and a small amount of formic acid can accelerate the dealdehyde reaction, resulting in a rapid decline in the relative molecular weight of POM. Therefore, the plasticizing temperature should be strictly controlled, and the roll temperature of 165 ~ 170 ℃ should be selected as the mixing temperature of the blend, and the time of 5min is more appropriate. Automotive glass laminated film production line www.www.dressup9x.com
The results show that the addition of Copa slightly increases the melting peak temperature (t..) and narrows the half peak width of 15 POM. This may be the solvent effect of Copa, which makes the - 54000 wave number / cm-i30002000 automotive glass laminated film production line www.www.dressup9x.com
POM molecular chain is easy to move, and the more perfect the crystallization is. The infrared spectrum analysis of the blends is consistent with the increase of T. of LDPE caused by the solvent effect of EVA in LDPE / EVA Blends. It can be seen from the cooling curve that the addition of Copa makes the crystallization temperature of the blend t. rise. Therefore, Copa has heterogeneous nucleation effect on POM. Scanning electron microscopy showed that POM was continuous phase, Copa was dispersed phase, and Copa was dispersed in POM matrix as spherical particles. With the increase of Copa content, the dispersed phase particles gradually increased and the dispersion uniformity became worse, resulting in the decrease of mechanical properties of the blends. Therefore, the dosage of Copa should be 2% by mass. Automotive glass laminated film production line www.www.dressup9x.com
POM can be blended with thermoplastic phenolic resin (novolak). The results of cloud point method showed that there was a low critical phase transition temperature in pomvol AK blends. DSC test showed that the melting point of POM / novolak blends decreased; According to the data obtained from DSC test, the X of POM and novolak is about -0.032 by using Hoffman weeks equilibrium melting point extrapolation method and Flory melting point decline equation. FTIR study showed that the hydroxyl group of novolak could form hydrogen bond with the ether oxygen group of POM, resulting in the shift of the hydroxyl peak of novolak to high frequency. POM and novolak can achieve thermodynamic compatibility. Fig. 6-20 is the FTIR spectrum of pure novolak and its blends with POM at wave number 3200 ~ 3800cm-1.
Because novolak itself contains a large number of hydroxyl groups, the stretching vibration peak of hydroxyl groups will appear in the FTIR spectrum. Automotive glass laminated film production line www.www.dressup9x.com