Study On Characteristics Of Interface Reaction In Polymer Reaction Blends Process

Due to the thermodynamically immiscible characteristic for most polymer pairs, and simple blend can not enhance their mechanical property, it is necessary to add compatilizer directly or form it by in-situ method in blend process to make the polymer pairs become miscible. Now the in-situ compatibility method is widely used in reaction blend process. Because the properties of polymer blends are controlled by the amount and structure of compatilizer formed by the two phases interface reaction in in-situ compatibility blend process, it is significant for the study on polymer reaction blend to research the reaction between different functional groups in polymer chain in blend process. But most of the present researches only aimed at the concrete properties of polymer blends modified by compatibility blend, the formation process of compatilizer and interface reaction were few reported. Hence, the researches on the formation of compatilizer and interface reaction in polymer reaction blend were detailedly discussed in this thesis.At first, the non-compatible polypropylene/polyamide6 (PP/PA6) system was selected to study the interface reaction in reaction blend process. Two precursors (PP-g-TMI and PP-g-MAH) were prepared and blended with PP/PA6 respectively. The effect of compatibility for two polymer blends was compared. The results showed that both of PP-g-TMI and PP-g-MAH could react with PA6 to form compatilizer (PP-g-PA6). With the increase of the amount of precursors, the amount of PP-g-PA6 formed in interface increased. The effect of interface reaction between PP-g-MAH and PA6 was better than that between PP-g-TMI and PA6.Because of the worse solubility of PP in common temperature, it was difficult to quantitatively study on interface reaction in blend process. Therefore, the second part of this thesis was that using styrene-maleic anhydride (SMA) copolymer to substitute PP as main chain to study the interface reaction for SMA/PA6 system. SMA with different content of maleic anhydride (MAH) was prepared by solution copolymerization. SMA and PA6 were blended in Haake rheometer.The research on the reaction velocity and the structure of polymer blends in SMA/PA6 blend system showed that the interface reaction was very fast and completed during 3 minutes. When the SMA/PA6 blend ration was 10/40, the complex PA6 grafting structure in SMA-g-PA6 was formed.The research on the influence factors of SMA/PA6 blend system showed that the effect of reaction temperature on interface reaction was small. When the content of MAH in SMA was 7.75% and SMA/PA6 blend ratio was 25/25, the SMA reacted percent decreased into 6.5% from 31.8% when SMA/PA6 blend ratio was 40/10. And the content of PA6 in SMA-g-PA6 decreased into 41.8% from 43.1%, the melting temperature decreased into 212℃from 216℃, the crystal temperature decreased into 163℃from 170℃. When the SMA/PA6 blend ratio was 10/40, with the increase of the content of MAH in SMA, the compatibility between SMA and PA6 became better. But when the content of MAH in SMA was higher than 2.89%, with the increase of the content of MAH in SMA, the compatibility between SMA and PA6 was similar to that when the content of MAH in SMA was 2.04%. The melting temperature and crystal temperature had nothing to do with the content of MAH in SMA. When the SMA/PA6 blend ratio was 25/25, with the increase of the content of MAH in SMA, the SMA reacted percent and the amount of SMA-g-PA6 increased, the content of PA6 in SMA-g-PA6 didn't change at first and then decreased, the melting temperature of SMA-g-PA6 kept constant.The research on the SMA/PA6 blends extracted by HCL showed that the MAH percent reacted in per SMA chain decreased with the increase of the content of MAH in SMA. And the total amount of MAH reacted and NH₂ reacted in the whole reaction system increased, the MAH reacted percent in per SMA chain decreased with the increase of the content of SMA in SMA/PA6 blend ratio.