fhu3524 wood adhesives and adhesion technology
DESCRIPTION
adhesiveTRANSCRIPT
FHU3524 WOOD ADHESIVES AND ADHESION TECHNOLOGY
SEMESTER 2, 2014/15
LAB REPORT 3 & 4
DETERMINATION OF PHYSICAL PROPERTIES OF RESINS PART 1 & 2
Name :WAN ABDUL RAHMAN BIN WAN ZAMANI
Matric No. :181072
Lecturer :DR. UMMI HANI ABDULLAH
Instructor :MS. AISYAH HUMAIRA ALIAS MR FARIBORZ HASHEMI MR AMIN MORADBAK
INTRODUCTION
Resins can be classified into two types, natural and synthetic resin. Natural resins are extracts of the vegetable or animal origin. These include rosin (gum, wood or tall oil rosins from tree and plant exudates; wood extracts; or by products from paper manufacturing), fossil resins such as amber; mined resins such as shellac as secretion product from an insect; and their main derivatives.
An adhesive in a broad sense is a substance which can bind two surfaces together by adhering them strongly. Adhesives find their frequent application because they weld two surfaces rapidly Urea formaldehyde (UF) adhesives are thermosetting when heated, Phenol formaldehyde (PF) are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde.
1. NON-VOLATILE CONTENT (SOLIDS CONTENT)
The solid content of adhesives is an important parameter for the possibilities for our products and production. The solid content influences drying time, moisture effects on substrates and mostly of less importance shrinking.
Solid content describes how much water we can expect in water-based adhesive. Most typical adhesives have a solid content around 50%. Starch based adhesives mostly have a solid content of 5-20% and some synthetical products up top 80 or 90%. Dextrine based adhesives can be around 70% solid content. Animal-glue (gelatin, protein adhesive) mostly has a solid content of 60-70%. These adhesives have an application temperature of ca. 70 degrees celcius.
OBJECTIVE: To determine the non-volatile content (solids content) of resins.
MATERIALS:
Petri Dish Analytical Balancer Oven Phenol Formaldehyde Urea Formaldehyde
METHODS:
1. The first step is weight (use for decimals) the empty petri dish.
2. Weight for two petri dish. It is one for Urea Formaldehyde (UF) and one for Phenol Formaldehyde (PF).
3. Then tare the analytical balancer.
4. Add 5 grams of Urea Formaldehyde (UF) and 5 grams of Phenol Formaldehyde (PF) for each petri dish.
5. Put the petri dish into the oven for 1 day at 100+5°C
6. Weigh and record the data.
2.GEL TEST FOR LIQUID RESINS
INTRODUCTION
Gel time is another term that is often used interchangeably with pot life, although there are some differences. Both terms are used to describe the thickening of an epoxy after it is mixed, but gel time is often tested at elevated temperatures as well. Gel time is determined by heating the epoxy and observing when it starts to become gel-like, though not quite fully cured. It will most likely be at a higher viscosity the end of it pot life measurement. This value can be useful for manufacturing purposes if one needs to move a part before the cure is complete, but does not want any shift in a component placement. It is not, however, a standard quality control test and should be determined experimentally in each application, if needed.
OBJECTIVE: To determine the amount of time needed to gel or cure a sample of resin.
MATERIALS:
Test tube Beaker Analytical balancer
METHODS:
1. Take a test tube and place 5 grams of Urea Formaldehyde to be tested into it.
2. Place the beaker in the hot water plate. That is the boiling water on it. Put the test tube that are already UF inside there.
3. Record timing and stir the resin at all times with a glass rod until the resin gels and starts to come out from the side. Then stop the timing.
3.DETERMINATION OF pH OF LIQUID RESIN
INTRODUCTION
Ph as we know a measure of the acidity or alkalinity of a solution, numerically equal to 7 neutral solutions, increasing with alkalinity and decreasing with acidity, The pH scale commonly in use ranges from 0 to 14. Every adhesives or resins have a ph value which is acidity or alkalinity.
OBJECTIVE: To determine the pH resin.
MATERIALS:
Phenol Formaldehyde Urea Formaldehyde pH meter
METHODS:
1. Calibrate pH meter with buffer solutions having 4.0 then with pH 10.00. Weigh 50grams of resins in a 100ml beaker. Determine the pH of the resin by immersing the electrode into the resin. Record the reading after 3-5 minutes.
LABORATORY 4
4.WATER TOLERANCE (STICKY MATTER)
INTRODUCTION
On this experiment students has to test the stickiness (adhesion) of household "glues" to determine strength or weakness of the substance to stick two surfaces together. This is for physical property of matter, the main function is to explain usefulness of a manufactured product depends on its function for a particular purpose.
MATERIALS:
Beaker Urea Formaldehyde Test Tube
METHODS:
1. Measure 10ml of Urea Formaldehyde into a 100mL test tube that have cool water.
2. Stir the UF. Add water in portion of 10mL each and thoroughly mix and check the cylinder sides for the presence of sticky matter.
RESULTS AND DISCUSSION
As shown in table 1 the result for the physical properties of UF and PF resin of 4 test that are already done. It is for the test solid content, gel test, pH and sticky matter.
Samples Solid Content % Gel Test (min) pH Sticky Matter (mL)
Urea Formaldehyde
40.7177 9.14 8.29 30
Phenol Formaldehyde
64.3780 NA 12.98 NA
Table 1 : The physical properties of UF and PF resins
Table 1 shows the variation of 4 test for solid content, gel test, pH and sticky matter of the Urea Formaldehyde (UF) and Phenol Formaldehyde (PF). The percentage of solid content test for UF is 40.7177%, while for PF is 64.3780%. It is show the percentage of solid content test for UF is higher than PF. According to the gel test, it just do for UF only. That is UF take for 9.14 minutes for the resins become to the gel onto the hot water plate. The pH values of UF is lower than PF. The pH value for UF is 8.29 in the alkaline condition, while the pH values for PF is 12.98 also in alkaline condition. Where we can see, the pH values are higher, the solid content also become higher. And then, the result for sticky matter is 30mL that are use for the resin presence of sticky matter. It is just do for UF only. The opposing effects of gelation and viscosity limits the tendency to cross linking action and the spread ability of the adhesive at these pH ranges otherwise rapid cross linking would make the adhesive become invisible solid, unable to flow and spread on the adherents for ease of bonding.
QUESTIONS:
1. Compare and discuss the properties of all resins that you have tested
The resins that we used to tested is urea and phenol formaldehyde. The difference from the colour is urea formaldehyde is white in colour whereas phenol formaldehyde is dark brown in colour. Similarities both resins is synthetic resin.
2.What is the relationships between solids content, pH value, and curing time.
Relationships Effect Importance
Solid content Influencing drying time
Moisture effects on substrate
Less important shrinking
pH values Influencing in solid content percentage
Higher ph number will give higher solid conten
To determine the ph scale, acidity or alkalinity depends on condition used
Curing time Solid content affecting the cure time of resins
The time taken adhesive to cure
The moment adhesive become harden and solidifying adherent
3. What is the ph of urea formaldehyde resins and phenol formaldehyde resin and their relationship with gel time?
The ph that were tested is the urea formaldehyde reading is 8.29 and phenol formaldehyde is 12.98 its show similarities between both resin is alkalinity because more than 7 ph is alkaline and less than ph 7 is acidity. The relation with gel time is the determination of resins when heated and observing when it starts to become gel-like it looks not colourless especially urea formaldehyde The relative el times of PF and UF , as well as taking consideration the relative rate constants of PF autocondensation. Figure 2 shows that relationship of gel time to pH for UF and PF resins.
Figure 2 Relationships of gel time to pH for UF and PF resins.
CONCLUSION
The conclusion can be made from this experiment shows that the urea formaldehyde (UF) resin and phenol formaldehyde (PF) can be prepared at acidic and alkaline conditions (pH 8 and 13) for use as an adhesive. The experimental results show that such preparations have high adhesive strength, high solid content (64.3780%) for PF and (40.7177%) for UF, moderate gel time, enough for it to spread on the surface of the adherends and set in a short time to bond the adherends strongly. The open vessel reactor was found suitable and may be adopted for small-scale industrial preparation. The pH values of UF resin is lower than PF resin, it also same with percentage of solid content. Where the percentage of solid content UF are lower than percentage of solid content PF resins. Here we can say, the higher pH values, the percentage of solid content are also become higher.