口罩用熔喷聚丙烯及无纺布中VOCs形成机理研究

Mechanism of VOCs formation in melt-blown PP resin and nonwoven fabric for mask

采用顶空-气相色谱-质谱联用技术(HS-GC-FID/MS)研究了分别采用过氧化物降解法和聚合法生产的5种熔喷聚丙烯(PP)以及2种口罩用熔喷无纺布中挥发性有机物(VOCs)的种类、相对含量、释放行为,并揭示了VOCs产生机理。结果表明:采用过氧化物降解法生产的PP中VOCs含量较高,VOCs主要由大量的酮类、醇类、醚类、环氧类等含氧基团类化合物以及少量的烯烃和烷烃等烃类化合物组成;采用聚合法生产的熔喷PP中VOCs含量较低,VOCs主要为烷烃类化合物。PP熔喷无纺布中VOCs含量较熔喷PP大幅降低。熔喷PP的VOCs中含氧基团类化合物主要为过氧化物降解剂自身分解的残留物。PP熔喷无纺布中VOCs含量大幅降低主要由于PP熔喷纺丝过程中高温快速脱除导致,但高温却导致PP降解形成了新烯烃类和酮类VOCs。

The types,relative contents,release behaviors of volatile organic compounds(VOCs)and the mechanism of VOCs formation in five kinds of melt-blown polypropylene resins(PP)produced by peroxide degradation and direct polymerization and two kinds of melt-blown PP nonwoven were studied by headspace-gas chromatography-flame ionization detector/mass spectrometry(HS-GC-FID/MS).The results show that VOCs contents in PP produced via degradation method is higher,which are composed of ketone compounds,alcohols,ethers,epoxy compounds and a small number of hydrocarbon compounds.VOCs contents in PP produced via polymerization is relatively low and are mainly composed of alkanes.Moreover,VOCs contents in melt-blown PP nonwoven is generally lower than that of melt-blown PP.The oxygen containing groups in VOCs from melt-down PP is residues of peroxide degradation agent after self-degradation.The rapid removal of VOCs from PP resin during the process of melt spinning leads to lower VOCs contents in melt-blown PP nonwoven,however,high temperature also accelerates the degradation of PP and forms new olefins and acetone of VOCs.