结构可控核壳改性剂的制备及其在PBT改性中的应用研究

Preparation of Controllable Core-shell Structural Modifier and Its Application in PBT

采用氧化还原种子乳液的聚合方法制备了结构可控、粒径均一、功能化的核壳结构改性剂聚丙烯酸丁酯/甲基丙烯酸甲酯/甲基丙烯酸共聚物P(BA/MMA-co-MAA),简称PBMMA,并研究了其对聚对苯二甲酸丁二醇酯(PBT)力学性能的影响。制备的乳液固含量为50%,聚合过程转化率几乎都达到99.5%以上,聚合过程中乳胶粒的增长过程用动态光散射(DLS)测量,其形态用透射电镜(TEM)观察。结果表明,加人的单体几乎都参加了反应,理论粒径与实测粒径基本吻合,最终粒径在334.2 nm左右,粒径分布系数(PDI)都小于0.08,粒径均一,具有明显的核壳结构,乳液聚合中没有明显的二次成核过程。傅里叶红外光谱(FTIR)说明功能单体(MAA)已经共聚到核壳改性剂上。PBMMA与PBT共混之后,使得PBT的缺口冲击强度显著提高,共混体系的力学性能与壳层功能单体(MAA)的含量相关,DMA和SEM测试结果可以证实。该研究有望应用于实际的工业生产中。

Poly（BA/MMA-co-MAA）, PBMMA, with core-shell structured copolymer was prepared by seeded emulsion polymerization and redox initiator system. Its effect on the mechanical properties of PBT was studied. Solids content of the emulsion was 50% , conversion rate of the polymerization process reached above 99.5%. The growth process of latex particles in polymerization was observed by dynamic light scattering （DLS） measurements, the morphology was observed with a transmission electron microscope （TEM）. The results showed that the addition of the monomer participated in almost all reactions, theoretical particle size basically consistented with the measured, the final particle size of about 334. 2 nm, the particle distribution index （PDI） was less than 0.08 with uniform particle size, and significant nuclear shell structure. The emulsion polymerization had no obvious secondary nucleation process. Fourier transform infrared spectroscopy （F＇FIR） showed the functional monomer （MAA） had been copolymerized onto the core-shell modifier. After PBMMA blended with PBT, the notched impact strength of PBT was significantly improved. The mechanical properties of blends were related with shell functional monomer （ MAA ） content confirmed by DMA and SEM. The study was expected to be used in practical industrial production.