Abstract
Maleic anhydride (MAH)–divinyl benzene (DVB) multi-monomer melt-grafting onto isotactic polybutene-1 (iPB-1) was carried out in a torque rheometer. The effects of dicumyl peroxide (DCP), MAH, and DVB concentrations, and temperature, on the reaction, were investigated. The optimized conditions were 170 °C, DVB/MAH = 4:6 (mass ratio). DVB as a comonomer enhanced the grafting degree (Gd) and grafting efficiency (Ge) of iPB-g-MAH better than styrene. The initiator DCP had little effect on Gd as its concentration over 0.2 phr, but the grafts’ melt flow rate (MFR) increased significantly, and relative molecular weight decreased remarkably with increased DCP concentration. With increasing Gd, the contact angle of grafts with water decreased, and there was a larger crystallization rate. The study of iPB-1 and iPB-g-MAH (Gd = 1.5%)-modified polyamide 6 (PA6) showed that iPB-g-MAH had an obviously toughening effect on PA6. With increasing iPB-g-MAH concentration, the blends of impact strength and elongation at break increased obviously, tensile strength decreased slightly, and MFR decreased prominently, which greatly slowed the processing degradation of PA6. The properties of iPB-1/PA6 blends deteriorated. Both DSC curves and SEM micrographs confirmed that PA6/iPB-g-MAH blends had much better compatibility than PA6/iPB. The reason was that the anhydride group in iPB-g-MAH reacted with amide group in PA6 to improve the compatibility between two phases, and iPB-g-MAH is an excellent modifier for PA6.
Highlights
The isotactic polybutene-1, invented by Natta and coworkers [1,2], is a widely used polymorphic polyolefin material [3,4,5] resulting from its excellent physical and mechanical properties, for instance, relatively high heat distortion temperature, low tendency to creep, and high stress-cracking resistance [6,7]
The reason was that the anhydride group in iPB-g-Maleic anhydride (MAH) reacted with amide group in polyamide 6 (PA6) to improve the compatibility between two phases, and iPB-g-MAH is an excellent modifier for PA6
The iPB-g-MAH is an excellent modifier for PA6
Summary
The isotactic polybutene-1 (iPB-1), invented by Natta and coworkers [1,2], is a widely used polymorphic polyolefin material [3,4,5] resulting from its excellent physical and mechanical properties, for instance, relatively high heat distortion temperature, low tendency to creep, and high stress-cracking resistance [6,7]. The application of iPB-1 was limited due to its disadvantages, such as slow crystallization rate, crystal transformation at room temperature [8,9,10], and low surface activity. There are many reports about the melt-grafting modification of polyethylene (PE) or PP using maleic anhydride (MAH) as monomer, but few reports have been found regarding the modification of iPB-1. The author’s team has been working on the functional modification of iPB-1 for many years [14,15,16,17,18]; MAH is the most widely used graft monomer, which contains both the double bonds that can be grafted and the functional groups for the subsequent chemical modification and it is not prone to homopolymerization under the processing conditions [19,20]. A previous study [17] showed that the polarity, crystallization rate, and the rate of conversion of form II to form I of iPB-1 were significantly accelerated after grafting
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
