Preparation Of Melamine Phosphate Glass And Study On Modified Nylon6 Composites

Phosphate glass(Pglass)is mainly composed of phosphorus pentaoxide,whose basic structure is P-tetrahedron and metal cation through the coordination bond.Pglass has low glass transition temperature(Tg)and excellent processability,which attract people’s interest.SnO-P2O5 glass(SPglass)is prepared in this article,and then modified by melamine(MEL)through ionic bonding for getting MEPglass.Then the effect of MEPglass on the crystallization and rheological properties of PA6 is explored.At the same time,MEPglass is used as a synergistic agent in flame-retarding polyamide-6(PA6)with aluminium diethylphosphinate(AlPi).The work not only extends the research scope of phosphate glass/polymer composites,but also realizes the application of phosphate glass in flame-retarding polymer.SPglasses with different Tg value are melt under different temperature,time and molar ratio by SnO and P2O5.The increase of melting temperature,melting time and SnO molar ratio in raw materials can improve the Tg of SPglass.With the increase of SnO mole ratio in the raw materials,the number of bridge oxygen bond(P-O-P)in the SPglass structure decreases,and the stability of the SPglass improves after coordination between P-tetrahedral and Sn2+.Considering Tg parameter and stability of SPglass,the suitable SPglass is prepared by SnO and P2O5 with 50:50 mole ratio at 500℃,60 min.After modified by MEL through ionic bonding,the finally MEPglass is used to blend with PA6.A series of PA6/MEPglass composites are prepared according to the percentage of MEPglass quality(2～30 wt%).With the addition of MEPglass,the melt temperature(Tm),crystallization temperature(Tc)and crystallinity(Xc)of PA6 are increased,the semi-crystallization time(t1/2)is prolonged.After adding 10 wt%MEPglass,Tm of PA6 reduces from 221.5℃ to 219.4℃,Tc decreases from 187.2℃ to 182.1℃,Xc changes from 29.5%to 26.8%,t1/2 increases from 0.38 min to 0.44 min.MEPglass can reduce the complex viscosity,storage modulus and loss modulus of PA6.After adding 10 wt%MEPglass,The complex viscosity of PA6(angular frequency 1.0 rad/s,behind the same)decreases from 469.0 Pa·s to 76.4 Pa·s,but the storage modulus reduces from 25.7 Pa to 5.4 Pa,the loss modulus decreases from 466.1 Pa,to 75.8 Pa.MEPglass is us,ed as a synergist to prepare halogen-free flame-retarded PA6 with AlPi.PA6 gets UL-94 V-0@3.2 mm rating when the amount of AlPi is 13 wt%alone.After adding 0.5 wt%MEPglas’s and 9 wt%AlPi,PA6 can get the same UL-94 rating,30.8%decreased in AlPi amount.From the cone calorimeter results,the total heat realease(THR)value of PA6/AlPi-9.5/MEPglass-0.5 decreas,es compared with that of PA6/AlPi-13,and the peak of rate of smoke release(pRSR)number changes from 41.2 to 68.8.The thermogravimetry-fourier transform infrared spectroscopy(TG-FTIR),X-ray nergy spectrum(EDX)and other tests are applied to explore the synergistic effect between AlPi and MEPglass.MEPglass can catch aluminum element in AlPi,and.promotes AlPi to generate more phosphorus free radicals.MEPglass improves the flame retardaney efficiency of AlPi in gaseo.us phase.Compared with single AlPi flame retardant PA6,the tensile strength of flame-retarded PA6 contained MEPglass increases by 8.5%,and the melt index increases by 13.3%.