A kind of preparation method of the high ventilated membrane of polylactic acidTechnical field
The present invention relates to technical field of macromolecules, in particular to the preparation method of a kind of high ventilated membrane of polylactic acid.
Background technique
Previous high ventilated membrane is all the non-biodegradable high ventilated membrane of PE class, generates white pollution after discarded, is destroyedEcological environment.PLA is the Biodegradable high molecular material obtained from reacting by series of physicochemical using cornstarch as primary raw materialMaterial not only has biological degradability, also has the function of natural bacteriostatic, but if packed with polylactic acid film to do vegetable and fruitFilm and/or infant's paper nappy, sanitary napkin counterdie, gas permeability are far from enough.The present invention is intended to provide a kind of polylactic acid height is ventilativeThe material and preparation method of film, have solved above-mentioned problem, expand the application range of PLA.
Summary of the invention
Technical problem to be solved by the invention is to provide a kind of preparation methods of the high ventilated membrane of polylactic acid, existing to solveCaused above-mentioned defects in technology.
To achieve the above object, the present invention provides a kind of technical solution below: preparation method of the high ventilated membrane of polylactic acid,Each component and ratio are as follows: PLA 30-35%, CaCO37-12%, PBAT 50-55%,25253-5% is specific rawSteps are as follows for production:
The first step first will be first by PLA, PBAT, CaCO according to the ratio prepared in advance3It is added in high speed mixer,3min is mixed under the revolving speed of 200r/min, then releases uniformly mixed material；
The material being uniformly mixed in the first step is added in screw extruder second step, then will2525 from sideSpout is added in double screw extruder, is squeezed out, tie rod, cooling, and modified PLA high ventilated membrane proper tree is obtained after pelletizingRouge, 170 DEG C of barrel temperature, 175 DEG C of die head temperature, extruder screw draw ratio is 52:1；
The PLA high breathable film special resin being modified obtained in second step is added in inflation film manufacturing machine unit and squeezes by third stepOut, inflation, traction, secondary inflation, cooling, second traction, winding obtain PLA high ventilated membrane, and barrel temperature is 170 DEG C, die head175 DEG C of temperature, first time blow-up ratio is 1~1.5, and second of blow-up ratio is 3.
It is using the beneficial effect of above technical scheme: a kind of preparation method of the high ventilated membrane of polylactic acid of the invention, it is excellentSelect the PBAT and CaCO of a small amount of particular molecule amount3, the toughness and gas permeability of PLA resin are increased, preferably2525 useAmount and the ventilative film forming process of special PLA high, improve PLA high ventilated membrane and squeeze out stability, stabilize the ventilative film thickness of PLA high,On the one hand obtained PLA high ventilated membrane thickness deviation improves PLA high within 0.005mm, using secondary blowing-up technology saturatingOn the other hand the physical mechanical property of air film has increased considerably the gas permeability of PLA high ventilated membrane, therefore secondary blowing-up technology isThe big main points of of the invention one.The present invention provides a kind of preparation methods of PLA high ventilated membrane, have expanded PLA application field, can be withInstead of traditional PE high ventilated membrane, it is possible to reduce white pollution, since PLA is natural bacteriostatic material, advantageous human health.
Specific embodiment
The preferred embodiment of the present invention.
Embodiment 1
By the PLA of 30 parts by weight, the PBAT of 55 parts by weight, the CaCO of 10 parts by weight3, 5 parts by weight2525, addEnter high speed mixer and 3min is mixed with 200r/min high, mixed material is added in the double screw extruder that draw ratio is 52:1 and is squeezedOut, tie rod, cooling, pelletizing obtain the dedicated modified resin of PLA high ventilated membrane, and twin-screw extruder barrel temperature is 170 DEG C, die head175 DEG C of temperature；By PLA high ventilated membrane dedicated modified resin investment inflation film manufacturing machine unit extrusion, inflation, traction, secondary inflation, coldBut, second traction, winding obtains the high ventilated membrane of polylactic acid, and barrel temperature is 170 DEG C, and 175 DEG C of die head temperature, first time blow-up ratioIt is 1~1.5, second of blow-up ratio is 3.Wherein within 0.005mm, longitudinal tensile strength is high ventilated membrane thickness deviation45.72MPa, transverse tensile strength 42.53MPa, longitudinal elongation at break rate 100.91%, transverse breakage elongation are158.63%, OTR oxygen transmission rate 5132cm3/(m2Datm), moisture-vapor transmission is 4426gmm/ (m2·d·atm)。
Embodiment 2
By the PLA of 33 parts by weight, the PBAT of 55 parts by weight, the CaCO3 of 7 parts by weight, 5 parts by weight2525, addEnter high speed mixer and 3min is mixed with 200r/min high, mixed material is added in the double screw extruder that draw ratio is 52:1 and is squeezedOut, tie rod, cooling, pelletizing obtain the dedicated modified resin of PLA high ventilated membrane, and twin-screw extruder barrel temperature is 170 DEG C, die head175 DEG C of temperature；By PLA high ventilated membrane dedicated modified resin investment inflation film manufacturing machine unit extrusion, inflation, traction, secondary inflation, coldBut, second traction, winding obtains the high ventilated membrane of polylactic acid, and barrel temperature is 170 DEG C, and 175 DEG C of die head temperature, first time blow-up ratioIt is 1~1.5, second of blow-up ratio is 3.Wherein within 0.005mm, longitudinal tensile strength is high ventilated membrane thickness deviation46.64MPa, transverse tensile strength 43.72MPa, longitudinal elongation at break rate 89.29%, transverse breakage elongation are125.84%, OTR oxygen transmission rate is 4621cm3/ (m2Datm), moisture-vapor transmission is 3696gmm/ (m2·d·atm)。
Embodiment 3
By the PLA of 35 parts by weight, the PBAT of 50 parts by weight, the CaCO3 of 12 parts by weight, 3 parts by weight2525,High speed mixer is added, 3min is mixed with 200r/min high, mixed material is added in the double screw extruder that draw ratio is 52:1Extrusion, tie rod, cooling, pelletizing obtain the dedicated modified resin of PLA high ventilated membrane, and twin-screw extruder barrel temperature is 170 DEG C, mould175 DEG C of temperature of head；By PLA high ventilated membrane dedicated modified resin investment inflation film manufacturing machine unit extrusion, inflation, traction, secondary inflation, coldBut, second traction, winding obtains the high ventilated membrane of polylactic acid, and barrel temperature is 170 DEG C, and 175 DEG C of die head temperature, first time blow-up ratioIt is 1~1.5, second of blow-up ratio is 3.Wherein within 0.005mm, longitudinal tensile strength is high ventilated membrane thickness deviation48.29MPa, transverse tensile strength 44.65MPa, longitudinal elongation at break rate 66.32%, transverse breakage elongation are95.24%, OTR oxygen transmission rate is 4853cm3/ (m2Datm), moisture-vapor transmission is 3925gmm/ (m2·d·atm)。
Comparative example 1
By the PLA of 30 parts by weight, the PBAT of 55 parts by weight, the CaCO of 10 parts by weight3, 5 parts by weight2525, addEnter high speed mixer and 3min is mixed with 200r/min high, mixed material is added in the double screw extruder that draw ratio is 52:1 and is squeezedOut, tie rod, cooling, pelletizing obtain the dedicated modified resin of PLA high ventilated membrane, and twin-screw extruder barrel temperature is 170 DEG C, die head175 DEG C of temperature；The dedicated modified resin investment inflation film manufacturing machine unit extrusion of PLA high ventilated membrane, inflation, traction, cooling, winding are obtainedThe high ventilated membrane of polylactic acid, barrel temperature be 170 DEG C, 175 DEG C of die head temperature, blow-up ratio 3.Wherein high ventilated membrane thickness deviation is equalWithin 0.005mm, longitudinal tensile strength 35.42MPa, transverse tensile strength 35.78MPa, longitudinal elongation at break rate is101.32%, transverse breakage elongation is 157.69%, OTR oxygen transmission rate 2321cm3/(m2Datm), vapor penetratesRate is 1563gmm/ (m2Datm), pass through comparative example 1 and example 1, it can be deduced that secondary blowing-up technology is big in systemAmplitude improves the gas permeability of high ventilated membrane, is the important means that PLA film gas permeability is improved in the present invention.
Comparative example 2
By the PLA of 40 parts by weight, the PBAT of 55 parts by weight, 5 parts by weight2525, be added high speed mixer with200r/min high mixes 3min, by mixed material be added extrusion in the double screw extruder that draw ratio is 52:1, tie rod, cooling,Pelletizing obtains the dedicated modified resin of PLA high ventilated membrane, and twin-screw extruder barrel temperature is 170 DEG C, 175 DEG C of die head temperature；It willThe dedicated modified resin of PLA high ventilated membrane puts into inflation film manufacturing machine unit extrusion, inflation, traction, secondary inflation, cooling, second traction, receiptsVolume obtains the high ventilated membrane of polylactic acid, and barrel temperature is 170 DEG C, and 175 DEG C of die head temperature, first time blow-up ratio is 1~1.5, secondSecondary blow-up ratio is 3.Wherein high ventilated membrane thickness deviation is within 0.005mm, longitudinal tensile strength 50.44MPa, laterally drawsStretching intensity is 45.90MPa, and longitudinal elongation at break rate 78.10%, transverse breakage elongation is 113.06%, OTR oxygen transmission rateFor 4453cm3/(m2Datm), moisture-vapor transmission is 3525gmm/ (m2·d·atm).Pass through comparative example 2 and example1, it can be deduced that CaCO3The effect for improving PLA banana is also functioned in system.
Based on a kind of above-mentioned, the preparation method of the high ventilated membrane of polylactic acid of structure of the invention, preferably a small amount of particular molecule amountPBAT and CaCO3, the toughness and gas permeability of PLA resin are increased, preferably2525 dosages and special PLA high are saturatingAir film moulding process improves PLA high ventilated membrane and squeezes out stability, stabilizes the ventilative film thickness of PLA high, and obtained PLA high is ventilativeOn the one hand film thickness deviation improves the Physical Mechanical of PLA high ventilated membrane using secondary blowing-up technology within 0.005mmCan, on the other hand increased considerably the gas permeability of PLA high ventilated membrane, obtained PLA high ventilated membrane deviation 0.005mm itInterior, OTR oxygen transmission rate is in 4621cm3/(m2Datm more than), moisture-vapor transmission is in 3696gmm/ (m2Datm) withOn.The present invention provides a kind of preparation methods of PLA high ventilated membrane, have expanded PLA application field, can replace traditional PE highVentilated membrane, it is possible to reduce white pollution, since PLA is natural bacteriostatic material, advantageous human health, the present invention passes through in PLA treeThe PBAT of high molecular weight is added in rouge, increases the toughness of PLA film by the high tenacity of PBAT itself, while CaCO is added3The gas permeability for increasing PLA film adds Germany watt gramMelt strength when 2525 steady extruding improves PLAHigh ventilated membrane blown film stability, then PLA banana is increased substantially by secondary blowing-up technology, it finally obtains a ventilativeThe good PLA film of property.
What has been described above is only a preferred embodiment of the present invention, it is noted that for those of ordinary skill in the artFor, without departing from the concept of the premise of the invention, various modifications and improvements can be made, these belong to the present inventionProtection scope.