ABSTRACT
Polyimides(Pis)areextensivelyusedinmicroelectronicsandaerospaceindustriesowingtotheirexcellentthermal,mechanicalanddielectricproperties[1-3]. AlthoughthePisutilizedformostapplicationsaretypicallyamorphous,theimportanceofcrystallinityhasledtorecenteffortstodevelopsemicrystallinePis, whicharealsosuitable.AclassofPImatricesforadvancedcomposites,which cancrystallizefromthemelt,wasdevelopedrecently.ThesePImatricesare knownbythenamesLARC-CPI[4,5],LARCCPI-2[6],PI-2[7],NewTPI[8-
10],TPEQ-ODPA[11]andTPER-BPDA[12].Theyallexhibitattractiveproperties,suchasexcellentthermalandoxidativestability,highmechanicalproperties, excellentresistancetosolventsandstrongbasesandhighadhesionproperties.A specialfeatureofthesepolymersistheirabilitytocrystallizefromthemeltto formcrystallinematricesforcompositematerials.Thisfeaturedistinguishesthem fromothersemicrystallinePIpowdersoftheLARC-TPItype[13],whichmeltin thetemperaturerange270-290°Canddonotre-crystallizeuponcooling.LARCTPIcancrystallizeaftermeltingonlyinthepresenceofresidualsolvent[14].
