A kind of castor oil modified benzoxazine resin and preparation method thereof

Abstract

The invention relates to a castor oil modified benzoxazine resin and a preparation method thereof. A castor oil-modified benzoxazine resin is obtained by cross-linking and solidifying after one-step reaction of diisocyanate, castor oil and bismethylol benzoxazine monomer. Preparation: mix castor oil and bis-hydroxymethyl benzoxazine monomers in a solvent evenly, according to the cyanate group in diisocyanate and the total hydroxyl groups in castor oil and bis-hydroxymethyl benzoxazine monomers The amount of the diisocyanate is 1:1 molar ratio, the diisocyanate is slowly added dropwise to the reaction solution to react, and after cooling, a castor oil-based polyurethane benzoxazine prepolymer is obtained; the obtained prepolymer solution is solidified to obtain a castor oil modified benzoxazine resins. The method introduces the natural renewable resource castor oil as a raw material to prepare the modified benzoxazine resin, which has good compatibility, flexibility and excellent dielectric performance, and the synthesis process is simple.

Description

Technical field

[0001] The invention relates to the technical field of organic polymer materials, in particular to castor oil modified benzoxazine resin, a preparation method and application thereof.Background technique

[0002] Benzoxazine (BOZ) is a six-membered heterocyclic compound containing O and N elements obtained by Mannich reaction of phenols, formaldehyde, and primary amines. It can undergo ring-opening polymerization under heating to form nitrogen-containing and Similar to the cross-linked network structure of phenolic resin. As a new type of thermosetting resin, polybenzoxazine has the advantages of excellent electrical insulation, good heat resistance, flame retardancy, low water absorption and good mechanical properties. Of particular concern is that the benzoxazine resin can be heated and cured without a catalyst, no small molecules are released during the curing process, the product has a low porosity, almost zero shrinkage, and has flexible molecular design. As an import...

Examples

Embodiment 1

[0028]The invention provides a method for preparing castor oil modified polyurethane benzoxazine composite resin, the preparation steps of which are:

[0029](1) Mix 60ml of toluene with 30ml of ethanol and pour it into a 500ml four-necked flask. Add 9.3g (75mmol) of p-hydroxybenzyl alcohol, 7.4g (37.5mmol) of diaminodiphenylmethane, and 4.5g (150mmol) of formaldehyde in sequence. Add to the flask, stir and mix uniformly at room temperature, then raise the temperature to 60°C, reflux for 12 hours, and stir at 300r / min. After the reaction is completed, the solution is poured into a beaker, and excess cold methanol is added for precipitation, then dried and ground to obtain a yellow powder, which is the DDM-type bis(hydroxymethyl)benzoxazine monomer.

[0030](2) Weigh 2.47g (5mmol) of the benzoxazine monomer prepared in step (1) in 50ml of toluene solution, stir thoroughly to dissolve it, then add 0.93g (1mmol) of castor oil, mix well and heat up to At 110°C, 1.59 g (6.35 mmol) of diphenylm...

Embodiment 2

[0033]The invention provides a method for preparing castor oil modified polyurethane benzoxazine composite resin, the preparation steps of which are:

[0034](1) Mix 60ml of toluene with 30ml of ethanol and pour it into a 500ml four-necked flask. Add 9.3g (75mmol) of p-hydroxybenzyl alcohol, 7.4g (37.5mmol) of diaminodiphenylmethane, and 4.5g (150mmol) of formaldehyde in sequence. Add to the flask, stir and mix uniformly at room temperature, then raise the temperature to 80°C, reflux for 4 hours, and stir at 500r / min. After the reaction is completed, the solution is poured into a beaker, and excess cold methanol is added for precipitation, then dried and ground to obtain a yellow powder, which is the DDM-type bis(hydroxymethyl)benzoxazine monomer.

[0035](2) Weigh 2.47g (5mmol) of the benzoxazine monomer prepared in step (1) in 50ml of xylene solution, stir thoroughly to dissolve, then add 0.93g (1mmol) of castor oil, mix well and raise the temperature At 100° C., 1.07 g (6.35 mmol) of h...

Embodiment 3

[0038]The invention provides a method for preparing castor oil modified polyurethane benzoxazine composite resin, the preparation steps of which are:

[0039](1) Mix 60ml of toluene with 30ml of ethanol and pour it into a 500ml four-necked flask. Add 9.3g (75mmol) of p-hydroxybenzyl alcohol, 7.4g (37.5mmol) of diaminodiphenylmethane, and 4.5g (150mmol) of formaldehyde in sequence. Add it to the flask, stir and mix uniformly at room temperature, then increase the temperature to 70°C, reflux for 10 hours, and stir at 400r / min. After the reaction is completed, the solution is poured into a beaker, and excess cold methanol is added for precipitation, then dried and ground to obtain a yellow powder, which is the DDM-type bis(hydroxymethyl)benzoxazine monomer.

[0040](2) Weigh 2.47g (5mmol) of the benzoxazine monomer prepared in step (1) in 50ml of dimethylformamide solution, stir thoroughly to dissolve, then add 0.93g (1mmol) of castor oil and mix After uniformity, the temperature was raised ...

Technical field

[0001] The invention relates to the technical field of organic polymer materials, in particular to castor oil modified benzoxazine resin, a preparation method and application thereof.Background technique

[0002] Benzoxazine (BOZ) is a six-membered heterocyclic compound containing O and N elements obtained by Mannich reaction of phenols, formaldehyde, and primary amines. It can undergo ring-opening polymerization under heating to form nitrogen-containing and Similar to the cross-linked network structure of phenolic resin. As a new type of thermosetting resin, polybenzoxazine has the advantages of excellent electrical insulation, good heat resistance, flame retardancy, low water absorption and good mechanical properties. Of particular concern is that the benzoxazine resin can be heated and cured without a catalyst, no small molecules are released during the curing process, the product has a low porosity, almost zero shrinkage, and has flexible molecular design. As an import...

Examples

Embodiment 1

[0028]The invention provides a method for preparing castor oil modified polyurethane benzoxazine composite resin, the preparation steps of which are:

[0029](1) Mix 60ml of toluene with 30ml of ethanol and pour it into a 500ml four-necked flask. Add 9.3g (75mmol) of p-hydroxybenzyl alcohol, 7.4g (37.5mmol) of diaminodiphenylmethane, and 4.5g (150mmol) of formaldehyde in sequence. Add to the flask, stir and mix uniformly at room temperature, then raise the temperature to 60°C, reflux for 12 hours, and stir at 300r / min. After the reaction is completed, the solution is poured into a beaker, and excess cold methanol is added for precipitation, then dried and ground to obtain a yellow powder, which is the DDM-type bis(hydroxymethyl)benzoxazine monomer.

[0030](2) Weigh 2.47g (5mmol) of the benzoxazine monomer prepared in step (1) in 50ml of toluene solution, stir thoroughly to dissolve it, then add 0.93g (1mmol) of castor oil, mix well and heat up to At 110°C, 1.59 g (6.35 mmol) of diphenylm...

Embodiment 2

[0033]The invention provides a method for preparing castor oil modified polyurethane benzoxazine composite resin, the preparation steps of which are:

[0034](1) Mix 60ml of toluene with 30ml of ethanol and pour it into a 500ml four-necked flask. Add 9.3g (75mmol) of p-hydroxybenzyl alcohol, 7.4g (37.5mmol) of diaminodiphenylmethane, and 4.5g (150mmol) of formaldehyde in sequence. Add to the flask, stir and mix uniformly at room temperature, then raise the temperature to 80°C, reflux for 4 hours, and stir at 500r / min. After the reaction is completed, the solution is poured into a beaker, and excess cold methanol is added for precipitation, then dried and ground to obtain a yellow powder, which is the DDM-type bis(hydroxymethyl)benzoxazine monomer.

[0035](2) Weigh 2.47g (5mmol) of the benzoxazine monomer prepared in step (1) in 50ml of xylene solution, stir thoroughly to dissolve, then add 0.93g (1mmol) of castor oil, mix well and raise the temperature At 100° C., 1.07 g (6.35 mmol) of h...

Embodiment 3

[0038]The invention provides a method for preparing castor oil modified polyurethane benzoxazine composite resin, the preparation steps of which are:

[0039](1) Mix 60ml of toluene with 30ml of ethanol and pour it into a 500ml four-necked flask. Add 9.3g (75mmol) of p-hydroxybenzyl alcohol, 7.4g (37.5mmol) of diaminodiphenylmethane, and 4.5g (150mmol) of formaldehyde in sequence. Add it to the flask, stir and mix uniformly at room temperature, then increase the temperature to 70°C, reflux for 10 hours, and stir at 400r / min. After the reaction is completed, the solution is poured into a beaker, and excess cold methanol is added for precipitation, then dried and ground to obtain a yellow powder, which is the DDM-type bis(hydroxymethyl)benzoxazine monomer.

[0040](2) Weigh 2.47g (5mmol) of the benzoxazine monomer prepared in step (1) in 50ml of dimethylformamide solution, stir thoroughly to dissolve, then add 0.93g (1mmol) of castor oil and mix After uniformity, the temperature was raised ...

Images