Preparation Of High-concentration Peroxide Masterbatch And Controlled Degradation Of Polypropylene

In order to prepare polypropylene(PP)fibers with high fluidity and applicable to melt spinning,it is usually necessary to add peroxide masterbatch to traditional PP.Due to the limitation of technology and scientific research level,the research and preparation of high-concentration peroxide masterbatch(>20%)in China is relatively slow,and it still needs to be imported from abroad.In this paper,for the purpose of preparing high concentration peroxide masterbatch,the following work is carried out:Analyzed and tested CRPP20X imported from South Korea to de-termine the type of peroxide(2,5-dimethyl-2,5di(tert-butylperoxy)hex-ane(D25))and content(18.8%),And studied the melting and crystallli-zation behavior of the carrier resin through thermodynamic analysis,which provides a reference for the preparation of peroxide masterbatch in the laboratory.Based on the laboratory XSS-300 co-directional parallel twin-screw extruder,the peroxide selects D25,and analyzes the feasibility of several olefin materials with low melting points and good compatibility with PP as carrier resins.Finally,formula 5#of high concentration peroxide mas-terbatch was prepared.The content of D25 in the 5#formula is 20.68%,which is higher than that of imported samples from South Korea.The prepared sample 5#was used to control the degradation of homopolymer PP140,and the added amounts were 0%,0.35%and 0.61%,respectively.With the increase in the amount of sample 5#,the fluidity of PP gradually increases.When the amount is 0.61%,the melt flow rate(MFR)increases to 94.03 g/10min(190 0 C,2.16kg),and the fluidity increases by about 10 times;when adding 0.35%of 5#sample,the weight average molecular weight(Mw)was reduced from 144,000 to 71,000,and the molecular weight distribution(PDI)was reduced from 4.12 to 2.73,but after the amount of 5#sample continued to increase,due to The degree of molecular chain branching and cross-linking increases,leading to an increase in Mw(90,000)and a decrease in PDI to 2.05;crystallization angle analysis,after the modification of sample 5#,the crystallization rate of PP140 is accelerated,the crystallinity is increased,and the spherulite size is reduced small.Comprehensive analysis results from various angles:The sample of 5#peroxide masterbatch can effectively degrade PP140 and improve the fluidity of PP,but the content of masterbatch needs to be controlled.Weakening the degradation effect.According to the customer's opinion,continue to modify the formula and process based on the 5#sample,and finally prepare the 11#pero-xide masterbatch formula that meets the customer's requirements.The content of D25 is 20.36%.And the storage performance was checked,and it was found that the peroxide masterbatch should not be stored under open conditions,but it can be stored under sealed conditions for more than 6 months.