The performances of rubber-toughened polymers like acrylonitrile-butadiene-styrene (ABS) are strongly affected by the type and amount of rubber phase. Characterization of rubber phase is an effective method to predict and control the physical and mechanical behaviors of ABS materials. In this work, different methods have been employed to determine the amount of rubber phase in ABS polymers. The first method was based on thermogravimetry using a particular step degradation of the polymer. In the second method, characteristic absorption bands in the Fourier transform infrared spectra were used to make a calibration curve to determine the rubber content of unknown ABS samples. The third method was based on variation of heat capacity of ABS polymers with increasing the rubber phase content. In the fourth method, a two-step solvent extraction followed by centrifuging was used to separate the rubber particles of different ABS samples. Separation of hardened rubber particles was used to study the size and size distribution of rubber particles.
A series of experiments were designed and conducted to determine the significance of process parameters in the grafting of styrene and acrylonitrile onto polybutadiene seeds in a semicontinuous emulsion copolymerization system. The significances of the parameters were obtained by comparing the variance ratios, or F values, with F-distributions. The significance level of each test (a-value) was obtained by variance analysis. The important process parameters in industrial polymerization processes are usually monomer-to-polymer ratio, initiator type and concentration, chain-transfer agent, and reaction temperature. The target responses were final monomer conversion, grafting degree, grafting efficiency, gel percent, and viscosity-average molecular weight of free styrene-acrylonitrile (SAN). The analysis of variance indicated that cumene hydroperoxide as the initiator and reaction temperature had strong effects on the graft structure. Moreover, free SAN molecular weight was significantly affected by the monomer/polymer ratio and cumene hydroperoxide and n-dodecyl mercaptan as chaintransfer agents. The raspberry-like morphology of grafted acrylonitrile-butadiene-styrene (ABS) particles and phase separation within the particles were confirmed by transmission electron microscopy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.